bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of RFID Tags Coil's System Stability under Delayed Electromagnetic Interferences
Authors: Aluf Ofer
Published: November 2012

This article discusses the very crucial subject of RFID TAG's stability. RFID equivalent circuits of a label can be represented as Parallel circuits of Capacitance (Cpl), Resistance (Rpl), and Inductance (Lpc). We define V(t) as the voltage that develops on the RFID label therefore making dV(t)/dt the voltage-time derivative. Due to electromagnetic interference, there are different time delays with respect to RFID label voltages and voltage time derivatives. We define V1(t) as V(t) and V2(t) as dV(t)/dt. The delayed voltage and voltage derivative are V1(t-τ1) and V2(t-τ2) respectively (τ***1=τ2). The RFID equivalent circuit can be represented as a delayed differential equation that depends on variable parameters and delays. The investigation of RFID's differential equation is based on bifurcation theory [ 1 ], which is the study of possible changes in the structure of the orbits of a delayed differential equation as a function of variable parameters. This article first illustrates certain observations and analyzes local bifurcations of an appropriate arbitrary scalar delayed differential equation [ 2 ]. RFID label stability analysis is done under different time delays with respect to label voltage and voltage derivative. Additional analysis of the bifurcations of RFID's delayed differential equation on the circle. Bifurcation behavior of specific delayed differential equations can be condensed into bifurcation diagrams. This serves to optimize dimensional parameters analysis of RFID TAGs under electromagnetic interferences to get ideal performances.
Re-description of Dysponetus joeli Olivier et al., 2012 (Polychaeta, Chrysopetalidae), with a new key to species of the genus
Authors: Darbyshire Teresa
Published: November 2012

Dysponetus is a genus of the family Chrysopetalidae with twelve currently described species. Specimens are fragile and easily damaged or broken during sampling making identification difficult. The most recently described species, Dysponetus joeli Olivier et al., 2012, from the Bay of Biscay and English Channel, was described from a few small, damaged and poorly preserved specimens. New specimens from the Isles of Scilly, in much better condition, resembled D. joeli except for the absence of ventral cirri on segment 3. Examination of the type material of D. joeli showed it to be identical to these new specimens and highlighted errors in the original description of the species. This paper corrects the errors and a revised key to species is produced. The differences between D. joeli and the two most similar species, D. bipapillatus Dahlgren, 1996 and D. macroculatus Dahlgren, 1996 are also detailed.
Effect of Application of Plant Growth Regulators on Earias vittella (Fabricius), Infestation and Yield Components of Cotton
Authors: S. Shahzad Ali  , G.H. Abro  , M.A. Rustamani  , Shafi Mohammad Nizamani
Published: November 2012

Studies were carried out on the effect of plant growth regulators on bollworm infestation and plant growth of cotton under field conditions. New cotton variety (CRIS-134) was sown in randomized block design with seven treatments including control (check) and was replicated three times on May 22, 2004. Mepiquate chloride, Acetyl salicylic acid and Naphthalene acetic acid (plant growth regulators) were applied on 10th, 25th August and 9thSeptember 2004.The results indicated that there was no significant effect of either removal of leaves and fruiting bodies of cotton plant and application of plant growth regulators on cotton plant height but significantly effect on volume of bolls and yield in comparison to control. Moreover, application of hormones significantly delayed the maturity of cotton. There was also significant effect of application of plant growth regulators on bollworm infestation compared with control treatments.
THE PREVALENCE OF METABOLIC SYNDROME IN WAR VETERANS WITH A CHRONIC POSTTRAUMATIC STRESS DISORDER
Authors: Babic Dragan , Maslov Boris , Stojakovic Milan
Published: November 2012

BACKGROUND: The Posttraumatic Stress Disorder (FTSD) and metabolic syndrome represent a growing number of public health problems in post-war countries. There is more and more evidence about a relationship between PTSD and metabolic syndrome as well as the research that indicates a high prevalence of metabolic syndrome in people suffering from PTSD. Understanding the relationship between PTSD and metabolic syndrome are important clinical and theoretical issues.OBJECTIVES: The objective of this study was to examine the prevalence of metabolic syndrome in war veterans with a chronic PTSD.METHODS; Metabolic syndrome was investigated in 100 male war veterans with combat PTSE) and in 79 males who needed medical attention in a dispensary of family medicine.RESULTS: According to NCEP: ATP 111 metabolic syndrome was found in 35 % of war veterans with PTSD. Metabolic syndrome was identified more frequently in PTSD patients with co-morbid depression (63.6%) and in war veterans with PTSD of high intensity (66.7%).CONCLUSION: Metablie syndrome was found in more than 1/3 patients suffering from a chronic PTSD, The frequency was higher if the clinical presentation of a chronic PTSD was heavier and if PTSD was co-morbid with a depressive disorder.
Increased Risk of Arthropathies and Joint Replacement Surgery in Patients With Genetic Hemochromatosis: A Study of 3,531 Patients and Their 11,794 First‐Degree Relatives
Authors: Elmberg Maria , Hultcrantz Rolf , Simard Julia F. , Carlsson Åke , Askling Johan
Published: November 2012

Objective

Genetic hemochromatosis (GH) is an autosomal recessive disease in individuals of Northern and Western European descent. Heterozygosity for the C282Y mutation is common (6–20%). Arthropathy is one of the few complications of GH suggested not to be associated with iron body stores; synovial iron deposition remains in iron‐depleted patients. Previous studies suggest an elevated prevalence of clinical and radiographic signs of arthropathy in patients with GH, and 2 smaller studies suggest a possibly elevated risk of joint replacement surgery, but more mixed results are shown regarding risks with HFE genotype. We therefore assessed the risks of arthropathy and joint replacement surgery in patients with GH and in their first‐degree relatives (FDRs).

Methods

We performed a population‐based cohort study of 3,531 patients with GH and of their 11,794 FDRs (assumed to be heterozygous for the C282Y mutation) using nationwide Swedish population‐based health and census registers. Hazard ratios (HRs) of arthropathies and joint replacement surgeries among patients and their FDRs (versus the general population) were assessed using Cox regression.

Results

Between 1997 and 2005, 406 of 3,531 patients were reported/hospitalized with any noninfectious arthropathies, including osteoarthritis, corresponding to an HR of 2.38 (95% confidence interval [95% CI] 2.14–2.64). Patients were also at increased risk of hip replacement (HR 2.77, 95% CI 2.27–3.38) and knee replacement (HR 2.14, 95% CI 1.58–2.88) surgery. Among the 11,794 FDRs (patients excluded), we found no increased risk of any of the joint morbidities.

Conclusion

Patients with GH, but not their FDRs, are at increased risk of arthropathies, including the need for joint replacement surgery.
Pulmonary Hypertension and Other Potentially Fatal Pulmonary Complications in Systemic Juvenile Idiopathic Arthritis
Authors: Kimura Yukiko , Weiss Jennifer E. , Haroldson Kathryn L. , Lee Tzielan , Punaro Marilynn , Oliveira Sheila , Rabinovich Egla , Riebschleger Meredith , Antón Jordi , Blier Peter R. , Gerloni Valeria , Hazen Melissa M. , Kessler Elizabeth , Onel Karen , Passo Murray H. , Rennebohm Robert M. , Wallace Carol A. , Woo Patricia , Wulffraat Nico ,   The Childhood Arthritis Rheumatology Research Alliance Carra Net Investigators
Published: November 2012

Objective

Systemic juvenile idiopathic arthritis (JIA) is characterized by fevers, rash, and arthritis, for which interleukin‐1 (IL‐1) and IL‐6 inhibitors appear to be effective treatments. Pulmonary arterial hypertension (PAH), interstitial lung disease (ILD), and alveolar proteinosis (AP) have recently been reported with increased frequency in systemic JIA patients. Our aim was to characterize and compare systemic JIA patients with these complications to a larger cohort of systemic JIA patients.

Methods

Systemic JIA patients who developed PAH, ILD, and/or AP were identified through an electronic Listserv and their demographic, systemic JIA, and pulmonary disease characteristics as well as their medication exposure information were collected. Patients with these features were compared to a cohort of systemic JIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry.

Results

The patients (n = 25) were significantly (P < 0.05) more likely than the CARRA registry cohort (n = 389) to be female; have more systemic features; and have been exposed to an IL‐1 inhibitor, tocilizumab, corticosteroids, intravenous immunoglobulin, cyclosporine, and cyclophosphamide. Twenty patients (80%) were diagnosed with pulmonary disease after 2004. Twenty patients (80%) had macrophage activation syndrome (MAS) during their disease course and 15 patients (60%) had MAS at pulmonary diagnosis. Sixteen patients had PAH, 5 had AP, and 7 had ILD. Seventeen patients (68%) were taking or recently discontinued (<1 month) a biologic agent at pulmonary symptom onset; 12 patients (48%) were taking anti–IL‐1 therapy (primarily anakinra). Seventeen patients (68%) died at a mean of 10.2 months from the diagnosis of pulmonary complications.

Conclusion

PAH, AP, and ILD are underrecognized complications of systemic JIA that are frequently fatal. These complications may be the result of severe uncontrolled systemic disease activity and may be influenced by medication exposure.
In Vitro Biocompatibility of Multiwalled Carbon Nanotubes with Sensory Neurons
Authors: Gladwin Karen M. , Whitby Raymond L. D. , Mikhalovsky Sergey V. , Tomlins Paul , Adu Jimi
Published: November 2012

Multiwalled carbon nanotubes (MWCNTs) possess unique properties rendering them a potentially useful biomaterial for neurobiological applications such as providing nanoscale contact‐guidance cues for directing axon growth within peripheral nerve repair scaffolds. The in vitro biocompatibility of MWCNTs with postnatal mouse spinal sensory neurons was assessed for this application. Cell culture medium conditioned with MWCNTs was not significantly toxic to dissociated cultures of postnatal mouse dorsal root ganglia (DRG) neurons. However, exposure of DRG neurons to MWCNTs dispersed in culture medium resulted in a time‐ and dose‐dependent reduction in neuronal viability. At 250 μg mL−1, dispersed MWCNTs caused significant neuronal death and unusual neurite morphologies illustrated by immunofluorescent labelling of the cytoskeletal protein beta (III) tubulin, however, at a dose of 5 μg mL−1 MWCNTs were nontoxic over a 14‐day period. DRG neurons grown on fabricated MWCNT substrates produced neurite outgrowths with abnormal morphologies that were significantly inferior in length to neurons grown on the control substrate laminin. This evidence demonstrates that to be utilized as a biomaterial in tissue scaffolds for nerve repair, MWCNTs will require robust surface modification to enhance biocompatibility and growth promoting properties.
Expeditious Synthesis of the Cores of Naturally Occurring Cyclic Polyethers using a Divergent Ring Rearrangement Metathesis Strategy
Authors: Escavabaja Philippe , Viala Jacques , Coquerel Yoann , Rodriguez Jean
Published: November 2012

Ring rearrangement metathesis (RRM) strategies are proposed for the expeditious synthesis of the cores of naturally occurring cyclic polyethers of the dysiherbaine and acetogenin families, as well as a hybrid compound, from 8‐oxabicyclo[3.2.1]octenes.
Effect of calcination temperature of TiO2 on the crystallinity and the permittivity of PVDF‐TrFE/TiO2 composites
Authors: Kuang Xiwen , Gao Qian , Zhu Hong
Published: November 2012

Composite membranes of poly(vinylidene‐trifluoroethylene)/titanium dioxide (PVDF‐TrFE/TiO2) were prepared by the solution cast method. The crystallization behavior and dielectric properties of the composites with TiO2 calcined at different temperatures were studied. Transmission electron microscopy and X‐ray diffraction (XRD) results showed that the TiO2 nanoparticles calcined at different temperatures were well dispersed in the polymer matrix and did not affect the structure of the PVDF‐TrFE matrix. XRD and differential scanning calorimeter measurements showed that the crystallinity of PVDF‐TrFE/TiO2 composites increased as the addition of TiO2 with different calcination temperatures. The dielectric property testing showed that the permittivity of PVDF‐TrFE/TiO2 membrane increased rapidly with the increase of TiO2 content and the calcination temperature of TiO2 at constant TiO2 content, but the dielectric loss did not change much. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Conservation status and reproduction of the critically endangered freshwater pearl mussel (Margaritifera margaritifera) in Northern Ireland
Authors: Reid Neil , Keys Alan , Preston Jane S. , Moorkens Evelyn , Roberts Dai , Wilson Conor D.
Published: November 2012

Freshwater unionoids are one of the most threatened animal groups worldwide and the freshwater pearl mussel Margaritifera margaritifera is currently listed as critically endangered in Europe. The EC Habitats Directive requires that EU Member States monitor the distribution and abundance of this species and report regularly on its conservation status.

The pearl mussel meta‐population in Northern Ireland was surveyed to assess temporal population trends in Special Areas of Conservation (SACs) and mussel reproduction throughout its range.

Mussels occurred in six rivers and numbers within three SAC designated sites remained stable between 2004–2007 and 2011. The discovery of more than 8000 previously unknown individuals in the Owenreagh River contributed to an overall increase (+56.8%) in the total known population. All populations actively reproduced during 2010 with approximately half of all individuals gravid. Moreover, suitable salmonid hosts occurred at all sites with 10.7% of salmon and 22.8% of trout carrying encysted glochidia. Populations were composed entirely of aged individuals with little evidence of recent recruitment.

It is inferred that the break in the life cycle must occur during the juvenile stage when glochidia metamorphose and settle into the interstitial spaces within the substrate. Water quality parameters, most notably levels of suspended solids, exceeded the recommended maximum thresholds in all rivers.

It is posited that the deposition of silt may be the main cause of juvenile mortality contributing to a lack of recruitment. Consequently, all populations were judged to be in ‘unfavourable’ conservation status. Catchment‐level management plans are urgently needed to reduce siltation with the aim of improving recruitment. These results have implications for the success of ex situ conservation programmes; specifically, the size at which captive‐bred juveniles are released into the wild. Further research is required to assess the vulnerabilities of early life‐stages of M. margaritifera to siltation.

Copyright © 2012 John Wiley & Sons, Ltd.
Mitochondrial dysfunction in osteoarthritis is associated with down‐regulation of superoxide dismutase 2
Authors: Gavriilidis Christos , Miwa Satomi , von Zglinicki Thomas , Taylor Robert W. , Young David A.
Published: November 2012

Objective

Superoxide dismutase 2 (SOD2) is down‐ regulated in osteoarthritis (OA). This study was undertaken to investigate the functional effects of this down‐regulation in the context of oxidative damage and mitochondrial dysfunction.

Methods

Lipid peroxidation in articular cartilage from OA patients and from lesion‐free control subjects with femoral neck fracture was assessed by measuring malondialdehyde levels using the thiobarbituric acid reactive substances assay. Long‐range polymerase chain reaction amplification and a mitochondrial DNA (mtDNA) strand break assay were used to investigate the presence of somatic large‐scale mtDNA rearrangements in cartilage. Microscale oxygraphy was used to explore possible changes in mitochondrial respiratory activity between OA and control chondrocytes. RNA interference was used to determine the effects of SOD2 depletion on lipid peroxidation, mtDNA damage, and mitochondrial respiration.

Results

OA cartilage had higher levels of lipid peroxidation compared to control cartilage, and lipid peroxidation was similarly elevated in SOD2‐depleted chondrocytes. SOD2 depletion led to a significant increase in mtDNA strand breaks in chondrocytes, but there was no notable difference in the level of strand breaks between OA and control chondrocytes. Furthermore, only very low levels of somatic, large‐scale mtDNA rearrangements were identified in OA cartilage. OA chondrocytes showed less spare respiratory capacity (SRC) and higher proton leak compared to control chondrocytes. SOD2‐depleted chondrocytes also showed less SRC and higher proton leak.

Conclusion

This is the first study to analyze the effects of SOD2 depletion in human articular chondrocytes in terms of changes to oxidation and mitochondrial function. The findings indicate that SOD2 depletion in chondrocytes leads to oxidative damage and mitochondrial dysfunction, suggesting that SOD2 down‐regulation is a potential contributor to the pathogenesis of OA.
Self‐Assembly of Aniline Oligomers
Authors: Zhao Yanchai , Tomšík Elena , Wang Jixiao , Morávková Zuzana , Zhigunov Alexander , Stejskal Jaroslav , Trchová Miroslava
Published: November 2012

A great number of nano/microscaled morphologies have recently been prepared during the oxidation of aniline. At the early stage of oxidation, aniline oligomers are obtained, often in spectacular morphologies depending on reaction conditions. Herein, the flower‐like hierarchical architectures assembled from aniline oligomers by a template‐free method are reported. Their formation process is ascribed to the self‐assembly of oligoanilines through non‐covalent interactions, such as hydrogen bonding, hydrophobic forces, and π–π stacking. The model of directional growth is offered to explain the formation of petal‐like objects and, subsequently, flowers. In order to investigate the chemical structure of the oligomers, a series of characterizations have been carried out, such as matrix‐assisted laser desorption ionization, time‐of‐flight mass spectrometry, gas chromatography coupled with mass spectrometry analysis, X‐ray diffraction, and UV/Vis, Fourier‐transform infrared, and Raman spectroscopies. Based on the results of characterization methods, a formation mechanism for aniline oligomers and their self‐assembly is proposed.
Magnetic Polystyrene Nanosphere Immobilized TEMPO: A Readily Prepared, Highly Reactive and Recyclable Polymer Catalyst in the Selective Oxidation of Alcohols
Authors: Zheng Zhi , Wang Jianli , Zhang Miao , Xu Lixin , Ji Jianbing
Published: November 2012

The 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) radical immobilized on the magnetic polystyrene nanospheres (MPNs) was used as a recyclable catalyst in the oxidation of various alcohols. The new and simply prepared heterogeneous TEMPO/MPNs exhibits both similar versatility and efficiency to homogeneous TEMPO under basic Montanari conditions. The excellent stability of the MPNs enables the TEMPO/MPNs to be recycled more than 20 times without significant leaching of immobilized TEMPO radicals or degradation of Fe3O4 nanoparticles. Moreover, the magnetic response ensures the rapid separation and quantitative recycling of TEMPO/MPNs by simple magnetic decantation.
Substrate Recognition and Regioselective Catalysis with Complexes Bearing NR,NH‐NHC Ligands
Authors: Hahn F. Ekkehardt
Published: November 2012

Complexes bearing “protic” N‐heterocyclic carbene (NHC) ligands (NR,NH‐NHCs) have been shown to use the NH group of the NHC ligand for the formation of hydrogen bonds to selected substrates. This type of hydrogen bond can be used for substrate recognition, selection, and orientation. In contrast to related systems, the hydrogen bond donor and thus the molecular recognition unit is located in proximity to the metal center. This concept article discusses major strategies for the preparation of complexes bearing protic NHC ligands and their potential applications.
Microwave Synthesis of the CPM‐5 Metal Organic Framework
Authors: Sabouni R. , Kazemian H. , Rohani S.
Published: November 2012

The metal organic framework CPM‐5 (crystalline porous materials) was successfully synthesized and characterized for the first time using microwave irradiation as a rapid and facile synthesis method in about 10 min compared to several days crystallization time required for the conventional solvothermal approaches. Furthermore, CPM‐5 produced by microwave‐assisted synthesis exhibited a very high surface area of 2187 m2g–1 compared to, e.g., 580 m2g–1 of the conventionally synthesized samples. Moreover, the as‐synthesized CPM‐5 showed high carbon dioxide uptake.
Pareto Optimal Operating Solutions for a Semibatch Reactor Based on Failure Probability Indices
Authors: Dan A. , Maria G.
Published: November 2012

When highly exothermic/hazardous reactions are conducted in the presence of parametric uncertainty, derivation of optimal operating policies for a semibatch reactor has to simultaneously consider several objectives of sustainability. This paper presents a methodology to generate the Pareto optimal solutions when reactor productivity (product yield) and safety objectives (expressed in probabilistic terms) are simultaneously considered in a simple way, in the presence of technological constraints, uncertainty in safety boundaries, and random fluctuations in control variables. Exemplification is made for a semibatch reactor of high thermal sensitivity used for the catalytic acetoacetylation of pyrrole with diketene in homogeneous liquid phase.
Equilibrium Model of a Continuous Crystallization Process for Separation of Substances Exhibiting Solid Solutions
Authors: Temmel E. , Müller U. , Grawe D. , Eilers R. , Lorenz H. , Seidel‐Morgenstern A.
Published: November 2012

Three general types of phase diagrams characterizing solid‐liquid equilibria are relevant for solution crystallization: simple eutectic, intermediate compound‐forming, and solid solution systems. Among these, a system capable to form solid solutions is very difficult to separate into its pure components. However, gradual fractional crystallization of two‐component solid solutions in a solvent is of large interest for the production of highly purified substances. A few publications suggest separation opportunities based on exploiting a cascade of batch crystallizers. A model‐based description of such a process by means of ternary phase diagrams is complicated. Due to the Gibbs phase rule there remains one degree of freedom in the region below the solubility curve, when temperature and pressure are fixed. This implies that the conodes, connecting one solid and one liquid state, do not converge into a pure component corner of the phase diagram. In this case, the specific courses of the conodes have to be determined experimentally. A simple empirical description of a phase diagram involving solid solutions is introduced and illustrated. Subsequently, a multistage crystallization process will be explained and modeled, based on the phase diagrams and the relevant mass balances.
Controlled Chain‐Scission of Polybutadiene by the Schwartz Hydrozirconation
Authors: Zheng Jun , Lin Yichao , Liu Feng , Tan Haiying , Wang Yanhui , Tang Tao
Published: November 2012

Controlled chain‐scission of polybutadiene (PB), polyisoprene, and poly(styrene‐co‐butadiene), induced by bis(cyclopentadienyl) zirconium hydrochloride (Cp2ZrHCl), was revealed at room temperature. The chain‐scission reaction of linear PB was studied by means of GPC, NMR spectroscopy, and MALDI‐TOF‐MS. It was confirmed that the molecular weights of degraded products were quasi‐quantitatively controlled by Cp2ZrHCl loading, irrespective of the starting PB, whereas the microstructure of PB chains was crucial to the scission reaction. The hydrozirconation of model molecules indicated that the existence of an internal double bond in compounds with multiple double bonds was essential for chain cleavage. The chain‐cleavage mechanism was proposed to involve hydrozirconation of internal double bonds in PB chains and β‐alkyl elimination. Furthermore, metallocene‐catalyzed chain‐scission by a chain‐transfer reaction was developed. It is believed that the reported chain scission offers a promising pathway for end‐group functionalization by chain cleavage and presents a new application of Schwartz’s reagent.
ChemInform Abstract: Copper(I) Iodide Catalyzed Synthesis of Quinolinones via Cascade Reactions of 2‐Halobenzocarbonyls with 2‐Arylacetamides.
Authors: Fu Liangbing , Huang Xiaoli , Wang Deping , Zhao Pinghua , Ding Ke
Published: November 2012

The scope is investigated providing a straightforward preparation of quinolinone, pyridinones, and heteroannnulated analogues in moderate to good yields.
ChemInform Abstract: Nanocelluloses: A New Family of Nature‐Based Materials
Authors: Klemm Dieter , Kramer Friederike , Moritz Sebastian , Lindstroem Tom , Ankerfors Mikael , Gray Derek , Dorris Annie
Published: November 2012

Review: 395 refs.
ChemInform Abstract: Stereoselective Synthesis of Polycyclic Thiopyrans.
Authors: Meier Herbert , Schmidt Michael , Mayer Axel , Schollmeyer Dieter , Beile Bernhard
Published: November 2012

Reactions of benzothiete (I) with bicyclic alkenes exhibit very high π‐side selectivity in the formation of polycyclic thiopyrans.
ChemInform Abstract: Phenylboronic Acid as Efficient and Eco‐Friendly Catalyst for the One‐Pot, Three‐Component Synthesis of α‐Aminophosphonates under Solvent‐Free Conditions.
Authors: Tibhe Gaurao D. , Bedolla‐Medrano Mercedes , Cativiela Carlos , Ordonez Mario
Published: November 2012

Aliphatic and aromatic aldehydes react with benzylamine and dimethyl phosphite within a short time to give the title compounds in good to excellent yields.
ChemInform Abstract: Simple Ultrasound‐Assisted Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐one and 3,4‐Dihydropyrimidine‐2(1H)‐thione‐Fused Steroidal Derivatives by a Three‐Component Reaction.
Authors: Dutta Mandakini , Gogoi Junali , Shekarrao Kommoori , Goswami Jonalee , Gogoi Sanjib , Boruah Romesh Chandra
Published: November 2012

The method allows the preparation of different types of biologically heterocyclic steroid systems and can also be applied to non‐steroidal cycloalkanones (X).
Amplified Two‐Photon Absorption in Trans‐A2B2‐Porphyrins Bearing Nitrophenylethynyl Substituents
Authors: Nowak‐Król Agnieszka , Wilson Craig J. , Drobizhev Mikhail , Kondratuk Dmitry V. , Rebane Aleksander , Anderson Harry L. , Gryko Daniel T.
Published: November 2012

We show that peripheral nitro groups enhance the maximum two‐photon absorption cross‐section of trans‐A2B2‐porphyrins bearing two phenylethynyl substituents by more than one order of magnitude. Maximum values as high as 1000 GM result from realization of suitable conditions for effective resonance enhancement along with a lowering of the energy and intensification of the two‐photon allowed transitions in the Soret region.
Construction of quasi‐cyclic low‐density parity‐check codes with low encoding complexity
Authors: Xu Hua
Published: November 2012

Low encoding complexity is very important for quasi‐cyclic low‐density parity‐check (QC‐LDPC) codes used in wireless communication systems. In this paper, a new scheme is presented to construct QC‐LDPC codes with low encoding complexity. This scheme is called two‐stage particle swarm optimization (TS‐PSO) algorithm, in which both the threshold and girth distribution of QC‐LDPC codes are considered. The proposed scheme is composed of two stages. In the first stage, we construct a binary base matrix of QC‐LDPC code with the best threshold. The matrix is constructed by combining a binary PSO algorithm and the protograph extrinsic information transfer (PEXIT) method. In the second stage, we search an exponent matrix of the QC‐LDPC code with the best girth distribution. This exponent matrix is based on the base matrix obtained in the first stage. Consequently, the parity‐check matrix of the QC‐LDPC code with the best threshold and best girth distribution are constructed. Furthermore, bit error rate performances are compared for the QC‐LDPC codes constructed by proposed scheme, the QC‐LDPC code in 802.16e standard, and the QC‐LDPC code in Tam's study. Simulation results show that the QC‐LDPC codes proposed in this study are superior to both the 802.16e code and the Tam code on the additive white Gaussian noise (AWGN) and Rayleigh channels. Moreover, proposed scheme is easily implemented, and is flexible and effective for constructing QC‐LDPC codes with low encoding complexity. Copyright © 2012 John Wiley & Sons, Ltd.
Modelling the impacts of reforestation on the projected hydroclimatology of Niger River Basin, West Africa
Authors: Oguntunde Philip G. , Abiodun Babatunde J. , Lischeid Gunnar , Merz Christoph
Published: November 2012

This study simulates the impacts of reforestation on hydroclimatology of Niger River Basin (NRB) under enhanced greenhouse gases (GHGs). A regional climate model (RegCM3) was used to dynamically downscale hydroclimatological variables of NRB for present‐day (PRS), and for future climate scenarios (with and without reforestation). The data were further analysed to detect changes in water balance components and the moisture recycling ratios. Under A1B scenario, warmer climate was projected over the entire basin in all seasons, a drier climate during the rainy season, and a wetter climate during the dry season. Reforestation along NRB (GBR) reduces the GHG warming over the basin both seasons, but increases it north‐east of the basin in July–September (JAS). Both reforestation scenarios could enhance rainfall over the reforested area. With reforestation over Sahel (GSR), seasonal evapotranspiration increases between 3·6% and 14·4%; but with GBR, evapotranspiration reduces between −12·4% and −4·3%. The GSR option offsets the projected annual GHG effects on moisture recycling over the basin. Evaporation coefficient decreased by about 5% under elevated CO2 while runoff coefficient increased. Reforestation reduces the projected warming and drying over the reforested zones because of its influence on the monsoon flow (reduction in speed). Hence, with reforestation in summer, the onset of monsoon delays in bringing in the cool moist air over the area located downwind of the reforested zone; this increases the temperature and reduces rainfall amount over the area. Copyright © 2012 John Wiley & Sons, Ltd.
Numerical modelling and measurement of cell trajectories in 3‐D under the influence of dielectrophoretic and hydrodynamic forces
Authors: Holzner Felix , Hagmeyer Britta , Schütte Julia , Kubon Massimo , Angres Brigitte , Stelzle Martin
Published: November 2012

This research is part of a program aiming at the development of a fluidic microsystem for in vitro drug testing. For this purpose, primary cells need to be assembled to form cellular aggregates in such a way as to resemble the basic functional units of organs. By providing for in vivo‐like cellular contacts, proper extracellular matrix interaction and medium perfusion it is expected that cells will retain their phenotype over prolonged periods of time. In this way, in vitro test systems exhibiting in vivo type predictivity in drug testing are envisioned. Towards this goal a 3‐D microstructure micro‐milled in a cyclic olefin copolymer (COC) was designed in such a way as to assemble liver cells via insulator‐based dielectrophoresis (iDEP) in a sinusoid‐type fashion. First, numeric modelling and simulation of dielectrophoretic and hydrodynamic forces acting on cells in this microsystem was performed. In particular, the problem of the discontinuity of the electric field at the interface between the fluid media in the system and the polymer materials it consists of was addressed. It was shown that in certain cases, the material of the microsystem may be neglected altogether without introducing considerable error into the numerical solution. This simplification enabled the simulation of 3‐D cell trajectories in complex chip geometries. Secondly, the assembly of HepG2 cells by insulator‐based dielectrophoresis in this device is demonstrated. Finally, theoretical results were validated by recording 3‐D cell trajectories and the Clausius–Mossotti factor of liver cells was determined by combining results obtained from both simulation and experiment.
Electrokinetic motion of a deformable particle: Dielectrophoretic effect
Authors: Ai Ye , Mauroy Benjamin , Sharma Ashutosh , Qian Shizhi
Published: November 2012

Electrokinetics‐induced motion and deformation of a hyperelastic particle confined in a slit microchannel has been numerically investigated for the first time with a full consideration of the fluid–particle–electric field interactions and the dielectrophoretic (DEP) effect. When the initial orientation of a cylindrical particle with respect to the applied electric field, θp0, is 90°, the particle tends to curl up as a “C” shape when moving from left to right. The electrokinetics‐induced particle deformation is due to the joint effects of the shear force arising from the non‐uniform Smoluchowski slip velocity on the particle surface and the asymmetric DEP force with respect to the center of the deformed particle arising from the spatially non‐uniform electric field surrounding the particle. The electrokinetics‐induced particle deformation is opposite to that of a particle moving in the same direction subjected to a pressure‐driven flow. When the initial particle orientation is 0<θp0<90°, a net torque arising from the DEP effect progressively rotates and aligns the particle with its longest axis parallel to the applied electric field, thus decreasing the non‐uniformity of the electric field and accordingly the particle deformation. The numerical predictions are in qualitative agreement with our previous experimental observation. The results show that the DEP effect is significant and must be taken into account in the modeling of electrokinetic motion of a deformable particle in microfluidics.
Electrodeless dielectrophoresis for bioanalysis: Theory, devices and applications
Authors: Regtmeier Jan , Eichhorn Ralf , Viefhues Martina , Bogunovic Lukas , Anselmetti Dario
Published: November 2012

Dielectrophoresis is a non‐destructive, label‐free method to manipulate and separate (bio‐) particles and macromolecules. The mechanism is based on the movement of polarizable objects in an inhomogeneous electric field. Here, microfluidic devices are reviewed that generate those inhomogeneous electric fields with insulating posts or constrictions, an approach called electrodeless or insulator‐based dielectrophoresis. Possible advantages compared to electrode‐based designs are a less complex, monolithic fabrication process with low‐cost polymeric substrates and no metal surface deterioration within the area of sample analysis. The electrodeless design has led to novel devices, implementing the functionality directly into the channel geometry and covering many areas of bioanalysis, like manipulation and separation of particles, cells, DNA, and proteins.
Interactions between chemical and climate stressors: A role for mechanistic toxicology in assessing climate change risks
Authors: Hooper Michael J. , Ankley Gerald T. , Cristol Daniel A. , Maryoung Lindley A. , Noyes Pamela D. , Pinkerton Kent E.
Published: November 2012

Incorporation of global climate change (GCC) effects into assessments of chemical risk and injury requires integrated examinations of chemical and nonchemical stressors. Environmental variables altered by GCC (temperature, precipitation, salinity, pH) can influence the toxicokinetics of chemical absorption, distribution, metabolism, and excretion as well as toxicodynamic interactions between chemicals and target molecules. In addition, GCC challenges processes critical for coping with the external environment (water balance, thermoregulation, nutrition, and the immune, endocrine, and neurological systems), leaving organisms sensitive to even slight perturbations by chemicals when pushed to the limits of their physiological tolerance range. In simplest terms, GCC can make organisms more sensitive to chemical stressors, while alternatively, exposure to chemicals can make organisms more sensitive to GCC stressors. One challenge is to identify potential interactions between nonchemical and chemical stressors affecting key physiological processes in an organism. We employed adverse outcome pathways, constructs depicting linkages between mechanism-based molecular initiating events and impacts on individuals or populations, to assess how chemical- and climate-specific variables interact to lead to adverse outcomes. Case examples are presented for prospective scenarios, hypothesizing potential chemical–GCC interactions, and retrospective scenarios, proposing mechanisms for demonstrated chemical–climate interactions in natural populations. Understanding GCC interactions along adverse outcome pathways facilitates extrapolation between species or other levels of organization, development of hypotheses and focal areas for further research, and improved inputs for risk and resource injury assessments. Environ. Toxicol. Chem. 2013;32:32–48. © 2012 SETAC
One‐Step Sonochemical Synthesis of Reduced Graphene Oxide/Pt/Sn Hybrid Materials and Their Electrochemical Properties
Authors: Anandan S. , Manivel A. , Ashokkumar M.
Published: November 2012

Low frequency ultrasound (20 kHz) was used for the reduction of graphene oxide (GO), Pt and Sn precursors with simultaneous loading of Pt and Sn monometallic and Pt–Sn bimetallic nanoparticles on the surface of reduced GO (rGO). The physicochemical characterizations of the catalysts were carried out using transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), energy dispersive X‐ray spectroscopy (EDX), and selected area electron diffraction (SAED) techniques. The reduced monometallic and bimetallic nanoparticles were spherical in shape with diameters around 2–6 nm, uniformly embedded on rGO sheets of few layers thickness. The electrocatalytic activities of the synthesized materials were evaluated by cyclic voltammetric studies.
Local Structure of Rare Earth Niobates (RE3NbO7, RE = Y, Er, Yb, Lu) for Proton Conduction Applications▴
Authors: López‐Conesa L. , Rebled J. M. , Chambrier M. H. , Boulahya K. , González‐Calbet J. M. , Braida M. D. , Dezanneau G. , Estradé S. , Peiró F.
Published: November 2012

Structural properties of rare earth niobates (RE3NbO7, RE = Y, Er, Yb, Lu) have been studied using selected area electron diffraction (SAED) and high resolution transmission electron microscopy (HRTEM). SAED patterns show diffuse scattering features along the [111] direction of the pure fluorite (Fm–3m) structure due to a short‐range ordering of anion vacancies in the fluorite structure or the change of coordination number around some cations. The latter is related to the presence of small domains of pyrochlore phase (Fd‐3m), which are observed in the HRTEM images.
Electron transfer dissociation versus collisionally activated dissociation of cationized biodegradable polyesters
Authors: Scionti Vincenzo , Wesdemiotis Chrys
Published: November 2012

Biodegradable polyesters were ionized by electrospray ionization and characterized by tandem mass spectrometry using collisionally activated dissociation (CAD) and electron transfer dissociation (ETD) as activation methods. The compounds studied include one homopolymer, polylactide and two copolymers, poly(ethylene adipate) and poly(butylene adipate). CAD of [M+2Na]2+ ions from these polyesters proceeds via charge‐remote 1,5‐H rearrangements over the ester groups, leading to cleavages at the (CO)O–alkyl bonds. ETD of the same precursor ions creates a radical anion at the site of electron attachment, which fragments by radical‐induced cleavage of the (CO)O–alkyl bonds and by intramolecular nucleophilic substitution at the (CO)–O bonds. In contrast to CAD, ETD produces fragments in one charge state only and does not cause consecutive fragmentations, which simplifies spectral interpretation and permits conclusive identification of the correct end groups. The radical‐site reactions occurring during ETD are very similar with those reported for ETD of protonated peptides. Unlike multiply protonated species, multiply sodiated precursors form ion pairs (salt bridges) after electron transfer, thereby promoting dissociations via nucleophilic displacement in addition to the radical‐site dissociations typical in ETD. Copyright © 2012 John Wiley & Sons, Ltd.
Innovative determination of polar organophosphonate pesticides based on high‐resolution Orbitrap mass spectrometry
Authors: Padilla‐Sánchez Juan Antonio , Plaza‐Bolaños Patricia , Romero‐González Roberto , Grande‐Martínez Ángel , Thurman Earl Michael , Garrido‐Frenich Antonia
Published: November 2012

The determination of compounds showing a very low molecular weight (i.e. < 200 Da) can be complicated when low‐resolution mass spectrometry is used in the selected‐reaction monitoring mode, since the possible number of product ions is reduced and the obtained reactions are not selective enough to overcome background noise and/or matrix interferences. In this study, the use of high‐resolution mass spectrometry based on Exactive Orbitrap was applied for the determination of a group of polar organophosphonate pesticides and transformation products (TPs), which show the aforementioned features, in agricultural soils. Namely, glyphosate, glufosinate, ethephon and their TPs, aminomethyl phosphonic acid (AMPA), 3‐methylphosphinicopropionic acid, N‐acetyl‐glufosinate and 2‐hydroxyethylphosphonic acid were analyzed. The [M‐H]‐ ions 168.00564, 180.04202, 142.96593, 110.00016, 151.01547, 222.05259 and 124.99982 were used, respectively, for the detection and identification of the compounds. Confirmation was carried out by using accurate mass measurements of ion fragments for each compound, from neutral losses of CO2, H2O and H2CO (formaldehyde). Furthermore, the recently reported tool, relative isotopic mass defect (RΔm), was also used to support the confirmation protocol. The optimized method was fully validated at low levels, including the estimation of a not commonly used parameter: the limit of confirmation (LOC). This LOC is expressed as the lowest concentration of compound that can be confirmed using a fragment or the RΔm, and it ranged from 10 to 50 µg kg−1 for all compounds. All the data was obtained in a single injection. Finally, the method was applied to real soil samples, and glyphosate and AMPA were found at 265 µg kg−1 and 105 µg kg−1, respectively. Copyright © 2012 John Wiley & Sons, Ltd.
Study of the efficiency for ion transfer through bent capillaries
Authors: Chen Tsung‐Chi , Xu Wei , Garimella Sandilya , Ouyang Zheng
Published: November 2012

Discontinuous atmospheric pressure interfaces (DAPIs) with bent capillaries represent a highly simplified and flexible means for introducing ions into a vacuum manifold for mass analysis or gas phase ion reactions. In this work, a series of capillaries of different radians and curvatures were used with DAPI for studying the impact of the capillary bending on the ion transfer. The variation of transfer efficiency was systematically characterized for dry and solvated ions. The efficiency loss for dry ions was less than one order of magnitude, even with a three‐turn bent capillary. The transfer of solvated ions generated by electrospray was found to be minimally impacted by the bending of the transfer capillary. For multiply protonated ions, the transfer efficiency for ions at lower charge states could be relatively well retained, presumably due to the lower reactivity associated with proton transfer reaction and the compensation in intensity by conversion of ions at higher charge states. Copyright © 2012 John Wiley & Sons, Ltd.
Investigation on accelerating FFT‐based methods for the EFIE on graphics processors
Authors: Attardo Elia A. , Francavilla Matteo A. , Vipiana Francesca , Vecchi Giuseppe
Published: November 2012

The use of graphic processor units (GPUs) has been recently proposed in computational electromagnetics to accelerate the solution of the electric field integral equation. In these methods, the linear systems obtained by using boundary elements are considered, and then an accelerated solution for a specific excitation is obtained. The existing studies are mostly focused on speeding up the filling time or the LU decomposition of that matrix. This limits the application to simple simulation scenarios if a fast method is not employed. In this paper, we propose a GPU acceleration for FFT‐based integral equation solvers. We will investigate the operations involved in the solver, and we will motivate the use of GPUs. Results of numerical tests will be reported firstly on a perfect electric conductor sphere with different radii; then a realistic aircraft will be considered. We found that using GPUs for FFT‐based methods allows achieving a reasonable speed‐up. Copyright © 2012 John Wiley & Sons, Ltd.
Statins may reduce femoral osteolysis in patients with total Hip arthroplasty
Authors: Lübbeke Anne , Garavaglia Guido , Rothman Kenneth J. , Bonvin Alexis , Roussos Constantinos , Miozzari Hermes , Hoffmeyer Pierre
Published: November 2012

In experimental studies, statin use has been associated with reduction of osteoclastic activity and promotion of bone formation around implants. Moreover, a large clinical study recently reported a substantially reduced risk of revision for aseptic loosening among statin users with THA. Our objective was to evaluate the influence of statin use on the development of femoral osteolysis within 5 years after THA. We conducted a case‐cohort study including all THAs presenting with femoral osteolysis at the 5 year visit (cases) and compared them with those without osteolysis (controls). Cases and controls were identified from a cohort of primary THAs operated between 2001 and 2005. Seven hundred thirty‐five THAs were included, mean age 68 years. Five years after surgery osteolysis had developed around the femoral component of 40 THAs (5.4%). Ever‐use of statins was much less frequent among cases (5 of 40, 12.5%) than among controls (199 of 695, 28.6%). The crude risk ratio of femoral osteolysis among statin users was 0.36 (95% CI 0.14; 0.92). After adjusting for age, sex, activity level, BMI, diagnosis, bearing surface, and type of stem, the adjusted risk ratio was 0.38 (95% CI 0.15; 0.99). In conclusion, statin use was associated with a reduced risk of developing femoral osteolysis 5 years after THA. Statins may be useful for reducing the risk of implant failure following THA. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 814–820, 2013