bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient calibration of the Hull White model
Authors: Schlenkrich Sebastian
Published: April 2011

In this paper we study the calibration of the Hull White interest rate model for the pricing of Bermudan swaptions and Bermudan bond options. A common modelling approach for the calibration of the Hull White model is to choose the model parameters such that market prices of corresponding European derivatives are replicated by the model. This requires that a multidimensional non‐linear optimization problem has to be solved. The focus of this paper lies in the efficient formulation and numerical solution of this optimization problem. We investigate the numerical properties of the iterative solution of the optimization problem by means of a Gauss Newton and an Adjoint Broyden quasi‐Newton method. Required derivatives of the objective function are evaluated by techniques of Automatic Differentiation. The algorithms are benchmarked to Minpack's general purpose solver HYBRD. Numerical results for the calibration of long‐term Bermudan swaptions are reported. Copyright © 2011 John Wiley & Sons, Ltd.
Design of sliding mode control for neutral delay systems with perturbation in control channels
Authors: Niu Yugang , Jia T. , Huang J. , Liu J.
Published: April 2011

This paper considers the problem of sliding mode control for a class of uncertain neutral delay systems. There are uncertainties not only in the state matrices, but also in the control matrix that results from perturbation in the control channels. By means of a sliding surface dependent on both the current states and delayed states, a sliding mode controller is designed such that the asymptotic stability of closed‐loop systems can be ensured. The design of both the sliding surface and the sliding mode controller can be obtained via convex optimization. It is shown that the state trajectories are driven onto the specified sliding surface in finite time and remain there for subsequent time. Finally, a numerical simulation example is provided. Copyright © 2011 John Wiley & Sons, Ltd.
Toward a generalized sub‐optimal control method of underactuated systems
Authors: Ordaz‐Oliver J. Patricio , Santos‐Sánchez Omar J. , López‐Morales Virgilio
Published: April 2011

In this paper, some experimental results and a performance analysis of a general control methodology for swinging up and stabilizing underactuated two‐link robots are presented. The analyzed methodology is based on Euler–Lagrange dynamics, passivity analysis, and dynamic programming theory. The applied control method preserves the general structure of a suboptimal control approach, while the functional defining a performance index is based on the underactuated system energy. In order to illustrate the presented approach, the swing up and stabilization control of two experimental electromechanical underactuated systems about an unstable equilibrium point are shown. Copyright © 2011 John Wiley & Sons, Ltd.
Thermal properties and stability of n‐octadecane based composites containing multiwalled carbon nanotubes
Authors: Bayramoglu Evren Çagˇlim
Published: April 2011

In this study, multiwalled carbon nanotubes (MWNT) were added to n‐octadecane at weight percentages of 1.25, 2.5, 5, 10 and changes of thermal properties of n‐octadecane were analyzed. Structural characterization of the materials was carried out by transmission electron microscope (TEM) and optical microscope. Thermal properties of n‐octadecane and its composites were evaluated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermal measurements show that the highest contribution to latent heat absorbing capacity with 18% was provided by the addition of 1.25% MWNT to n‐octadecane. The thermal properties and the thermal stability of pure n‐octadecane and its composites with MWNT were also investigated by subjecting the samples to 1440 melting‐cooling cycles. The sample with 1.25% MWNT content also showed the best thermal stability. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Off‐label prescribing patterns of antidepressants in children and adolescents
Authors: Lee Euni , Teschemaker Anna R. , Johann‐Liang Rosemary , Bazemore Gina , Yoon Martin , Shim Kye‐Sik , Daniel Marlon , Pittman Jerome , Wutoh Anthony K.
Published: April 2011

Purpose

To understand the extent of off‐label prescribing among pediatrics, the study assesses the prescribing patterns of antidepressants in ambulatory settings.

Methods

A cross‐sectional analysis was conducted using the National Ambulatory Medical Care Survey from 2000 to 2006. The prevalence of off‐label prescribing of antidepressants was estimated, and predictive factors were evaluated.

Participants

Children and adolescents aged 6–18 years to private physicians' offices.

Main Outcome Measures

Prevalence of antidepressant prescriptions including FDA and non‐FDA‐approved indications, types of antidepressants prescribed, and factors associated with off‐label prescribing.

Results

Our study population made 18 646 visits to private physicians' offices, representing about 667 million weighted visits during the study period. The mean age of the patients was 12.2 years (SD = 3.7), and majority of the visits were made by White people (73.1%). Of all visits, 3.7% (95%CI: 3.2%–4.2%) were associated with antidepressants. The most prevalent form of antidepressants prescribed were selective serotonin reuptake inhibitors (63.7%). Only 9.2% of the visits were associated with FDA‐approved indications. Visits made to pediatricians (adjusted OR = 2.4; 95%CI: 1.1–5.1), family physicians, and other offices (adjusted OR = 1.9; 95%CI: 1.2–3.1) were more likely to be associated with off‐label prescribing as compared with visits to a psychiatrist's office.

Conclusions

The study observed a very high prevalence of off‐label antidepressant prescribing patterns among children and adolescents in US ambulatory care settings. Coordinated efforts should be placed to evaluate the potential reasons and ramifications of antidepressant off‐label prescribing to guard patients' safety. Copyright © 2011 John Wiley & Sons, Ltd.
Zwitterionic shell‐crosslinked micelles from block‐comb copolymer of PtBA‐b‐P(PEGMEMA‐co‐DMAEMA)
Authors: Ding Zong‐Lei , He Wei‐Dong , Tao Jing , Jiang Wen‐Xing , Li Li‐Ying , Pan Ting‐Ting
Published: April 2011

Through reversible addition‐fragmentation chain transfer (RAFT) polymerization of t‐butyl acrylate (tBA) and RAFT copolymerization of 2‐dimethylaminoethyl methacrylate (DMAEMA) with poly(ethylene glycol) methyl ether methacrylate (PEGMEMA), block‐comb copolymer of PtBA‐b‐P(PEGMEMA‐co‐DMAEMA) was prepared. After the self‐assembly of PtBA‐b‐P(PEGMEMA‐co‐DMAEMA) into core‐shell spherical micelles, P(PEGMEMA‐co‐DMAEMA) segments of the shell was crosslinked with 1,2‐bis(2‐iodoethoxy)ethane and the core of PtBA was selectively hydrolysized with trifluoroacetic acid. Thus, zwitterionic shell‐crosslinked micelles with positively charged outer shell and negatively charged inner core were obtained. Dynamic light scattering, transmission electron microscope, Zeta potential measurement, and nuclear magnetic resonance were used to confirm the formation of the zwitterionic shell‐crosslinked micelles. They showed the excellent resistance to the variation of pH value and possessed the positive values throughout the whole range of pH range even if the carboxylic groups of the micelles was much more than ammonium groups. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Main‐chain chiral poly(2‐oxazoline)s: Influence of alkyl side‐chain on secondary structure formation in solution
Authors: Bloksma Meta M. , Rogers Sarah , Schubert Ulrich S. , Hoogenboom Richard
Published: April 2011

The synthesis and microwave‐assisted polymerization of a series of chiral 2‐oxazolines with varying alkyl pendant groups, namely R‐2‐ethyl‐4‐ethyl‐2‐oxazoline (R‐EtEtOx), R‐2‐butyl‐4‐ethyl‐2‐oxazoline (R‐BuEtOx), R‐2‐octyl‐4‐ethyl‐2‐oxazoline, 2‐nonyl‐4‐ethyl‐2‐oxazoline, and R‐2‐undecyl‐4‐ethyl‐2‐oxazoline (R‐UndeEtOx), are reported. A kinetic investigation of the polymerization of R‐EtEtOx revealed a living polymerization mechanism. The poly(2‐oxazoline)s containing an ethyl, butyl, and octyl pendant group form similar chiral structures according to circular dichroism measurements. When the pendant group is further elongated, the chiral structure becomes more flexible in trifluoroethanol and the thermal response in hexafluoroisopropanol (HFIP) significantly changes. The short‐range structure of poly‐R‐BuEtOx dissolved in HFIP is thermoresponsive in a complex way, due to HFIP hydrogen bonding to the polymeric amide groups, whereas the long‐range structure determined from small angle neutron scattering is insensitive to temperature demonstrating that only the local secondary structure changes with temperature. In addition, the chiral structure of poly‐R‐UndeEtOx depends on the polarity of the solvent. The short‐range structure becomes more flexible in polar solvents, most likely due to interactions with the amide groups disturbing the secondary structure. In contrast, the long‐range structural transition from an ellipsoid in the apolar n‐hexane to a rod structure in the polar n‐butanol is ascribed to better solvation of the long aliphatic side chains. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Mass spectrometric immunoassay of intact insulin and related variants for population proteomics studies
Authors: Oran Paul E. , Jarvis Jason W. , Borges Chad R. , Sherma Nisha D. , Nelson Randall W.
Published: April 2011

Purpose: The purpose of the work presented herein was to develop a high‐throughput assay for the quantification of human insulin in plasma samples while simultaneously detecting, with high mass accuracy, any additional variant forms of insulin that might be present in each sample.

Experimental design: A mass spectrometric immunoassay (MSIA) was designed in which anti‐human insulin antibodies were immobilized to commercially available mass spectrometric immunoassay pipette tips and used to capture insulin and related protein variants from human plasma.

Results: Standard curves for insulin exhibited linearity (average R2 for three days of analysis=0.99) and assay concentration limits of detection and limits of quantification for insulin were found to be 1 and 15 pM, respectively. Estimated coefficient of variations for inter‐day experiments (n=3 days) were <8%. Simultaneously, the assay was shown to detect and identify insulin metabolites and synthetic insulin analogs (e.g. Lantus). Notably, insulin variants not known to exist in plasma were detected in diabetics.

Conclusions and clinical relevance: This introductory study sets a foundation toward the screening of large populations to investigate insulin isoforms, isoform frequencies, and their quantification.
Silver‐induced conformational changes of polypeptides: a CD study
Authors: Murariu Manuela , Stela Dragan Ecaterina , Adochitei Adriana , Zbancioc Gheorghita , Drochioiu Gabi
Published: April 2011

The role of silver ions in various pathologies, as well as their effect on peptide conformation and properties are less understood. Consequently, we synthesized several peptides with various residues in their sequence to investigate silver‐induced conformational changes at various pH values by Circular Dichroism spectroscopy. Uniquely, the glycine‐based, histidine‐containing peptide showed a severe change from a random coil and β‐turn conformation to large α‐helices during silver binding. When comparing the effect of silver ions on the conformation of bradykinin a similar tendency was found. Besides, silver ions reduced the amyloid‐β peptide tendency to aggregation. Our results suggest a specific and protective role for silver ions in brain pathologies, which is related to their high affinity toward physiologically and pharmacologically active peptides. Fourier transform infrared spectroscopy studies as well as the mass spectrometric ones support our conclusions. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Conformational constraints in angiotensin IV to probe the role of Tyr2, Pro5 and Phe6
Authors: Lukaszuk Aneta , Demaegdt Heidi , Van den Eynde Isabelle , Vanderheyden Patrick , Vauquelin Georges , Tourwé Dirk
Published: April 2011

The aromatic amino acids Tyr and Phe in angiotensin IV (Ang IV) were conformationally constrained by the use of β‐Me substituted analogs, or cyclic constrained analogs. None of these modifications was allowed for Tyr1, while only e‐β‐MePhe6 substitution resulted in an AngIV analog with high IRAP potency and selectivity versus AP‐N or the AT1 receptor. This indicates an important role of the orientation of the Phe6 for inducing selectivity. Pro5 replacement with 2‐aminocyclopentanecarboxylic acid maintained IRAP potency and abolished AT1 affinity. These results confirm the importance of conformational constrained amino acids to generate selectivity in bioactive peptides. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Assessment of Extracts from Mistletoe (Viscum album) for Herb–Drug Interaction by Inhibition and Induction of Cytochrome P450 Activities
Authors: Doehmer Johannes , Eisenbraun Jürgen
Published: April 2011

Three commercially available extracts from mistletoe (Viscum album L.) grown on ash tree (abnobaVISCUM® Fraxini 20 mg), on fir (abnobaVISCUM® Abietis 20 mg), and on pine (abnobaVISCUM® Pini 20 mg) were tested in vitro for their potential to interfere with the major drug metabolizing cytochromes P450 by hepatocyte viability, by inhibition of cytochromes P450 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4, and by the induction of cytochromes P450 1A2, 2B6, 2C9, 2E1 and 3A4. As the three extracts are produced from mistletoe plants belonging to three different subspecies of Viscum album L. they have explicit differences in the content and spectrum of various active ingredients, e.g. mistletoe specific lectins. Cytotoxic effects on liver cells were observed for abnobaVISCUM® Fraxini with a high lectin content with an EC50 value of 2.56 µg/mL, for abnobaVISCUM® Abietis with a moderate lectin content with an EC50 value of 5.79 µg/mL and for abnobaVISCUM® Pini with a low lectin content with an EC50 value of 30.86 µg/mL. The induction of cytochromes P450 was tested on human liver cells from three donors. Inhibition of cytochromes P450 was carried out on human liver microsomes. No or minor induction and inhibition was observed for all three extracts. The data indicate no or minor potential for herb–drug interactions by interference with cytochromes P450 by any of the three mistletoe extracts. Copyright © 2011 John Wiley & Sons, Ltd.
Aged Red Garlic Extract Reduces Cigarette Smoke Extract‐induced Cell Death in Human Bronchial Smooth Muscle Cells by Increasing Intracellular Glutathione Levels
Authors: Jeong Yi‐Yeong , Park Hye‐Jin , Cho Young‐Woo , Kim Eun‐Jin , Kim Gyu‐Tae , Mun Yun‐Ja , Lee Jong Deog , Shin Jung‐Hye , Sung Nak‐Ju , Kang Dawon , Han Jaehee
Published: April 2011

Increasing antioxidant capacity has been proposed as a promising strategy to prevent cigarette smoke‐induced lung diseases. This study tested whether garlic extracts prevented cigarette smoke extract (CSE)‐induced cell death in human bronchial smooth muscle cells (HBSMCs). Garlic extracts were prepared from fresh raw garlic (FRG), aged black garlic (ABG) and aged red garlic (ARG). Treatment of HBSMCs with 10% CSE induced cell death accompanied by activation of caspase. Of the garlic extracts, treatment with ARG extract reduced CSE‐induced cell death. The combination of ARG extract with CSE attenuated the CSE‐induced reduction in glutathione (GSH) content, generation of reactive oxygen species (ROS) and induction of heme oxygenase‐1 expression compared with CSE treatment without ARG extract. Furthermore, the combination of L‐BSO, a GSH synthesis inhibitor, with ARG and CSE extracts failed to increase the intracellular GSH content and cell viability. Taken together, these results demonstrate that ARG extract reduces CSE‐induced cell death by increasing GSH content and reducing ROS generation in HBSMCs. Copyright © 2011 John Wiley & Sons, Ltd.
Shikonin Derivatives Protect Immune Organs from Damage and Promote Immune Responses In Vivo in Tumour‐bearing Mice
Authors: Long Su , GuangZhi Yan , BaoJie Guan , Wei Xu , YanYong Hao , YingLi Wang , Yang Zhang , LiHua Liu
Published: April 2011

Shikonin, a major component of Lithospermum erythrorhizon and Arnebia euchroma, exhibits antiinflammatory, immunomodulatory and antitumour activities. Although many recent studies have focused on the antitumour effects of shikonin, the exact mechanisms underlying its antitumour and immunomodulatory effects in tumour‐bearing mice remain unclear. The aim of the present study was to investigate the antitumour and immunomodulatory effects of shikonin derivatives (ShD) in tumour‐bearing mice. Swiss mice inoculated with hepatoma HepA22 or sarcoma 180 (S180) cells were treated with ShD or 5‐fluorouracil (5Fu). Survival time, immune organs, natural killer cell activity, lymphocytes, lymphocyte transformation and interleukin (IL)‐2 production were analysed. ShD significantly prolonged the survival (median survival time prolonged by >7 days) of tumour‐bearing mice in a dose‐dependent manner, inhibited the growth of transplantable neoplasms (inhibitory rate, > 33%), and recovered (at [ShD] = 2.5 mg/kg/day) or increased (at [ShD] > 5 mg/kg/day) the number of CD3‐ and CD19‐positive cells. ShD also played a role in protecting the immune organs from damage and reversed or enhanced immune responses, as noted by the nearly normal thymic structure; enlarged splenic corpuscles; and improved natural killer cell activity, lymphocyte transformation and IL‐2 production in ShD‐treated mice. ShD reduced the tumour load of tumour‐bearing mice and protected the immune organs against tumour‐induced damage and immune function impairment. Copyright © 2011 John Wiley & Sons, Ltd.
Icariin induces the Expression of Toll‐like Receptor 9 in Ana‐1 Murine Macrophages
Authors: Li Li , Peng Lina , Miao Jianhua , Qiu Yafeng , Zhou Ying , Gao Xiaoqi , Xu Yongli , Shi Zixue , Shao Donghua , Ma Zhiyong
Published: April 2011

Icariin is the major pharmacologically active compound of Herba epimedii which has been used as a tonic, aphrodisiac and an antirheumatic in traditional Chinese medicine. This study analysed the effect of icariin on the expression of Toll‐like receptor 9 (TLR9) which plays an important role in regulation of the innate immune response. Stimulation of Ana‐1 murine macrophages with icariin induced a significant dose‐dependent expression of TLR9, and its mRNA expression which increased from 3 h post‐treatment was approximately five‐fold that of DMSO‐treated cells. Several molecules, such as myeloid differentiation factor 88, tumor necrosis factor‐α and interleukin 6, which are involved in the TLR9 downstream signaling pathway, were also significantly up‐regulated in response to icariin stimulation. Our findings demonstrated that icariin is able to induce the expression of TLR9. Copyright © 2011 John Wiley & Sons, Ltd.
The Mechanism of Sesame Oil in Ameliorating Experimental Autoimmune Encephalomyelitis in C57BL/6 Mice
Authors: Ghazavi A. , Mosayebi G.
Published: April 2011

Experimental autoimmune encephalomyelitis (EAE) is a Th1 cell‐mediated autoimmune disease of the CNS that serves as an animal model for multiple sclerosis (MS). The study investigated the effectiveness of treatment with sesame oil on the development of EAE. EAE was induced in 8 week old C57BL/6 mice with an emulsion of MOG35‐55. Therapy with sesame oil (4 mL/kg/day as oral gavage) was started on day 3 before the immunization. IFN‐gamma and IL‐10 production from cultured spleen supernatants were determined by the ELISA method. The results showed that daily oral gavage of sesame oil significantly reduced the clinical symptoms of EAE in C57BL/6 mice. In addition, sesame oil‐treated mice displayed a significantly delayed disease onset. Mononuclear cells isolated from spleen of sesame oil‐treated mice showed a significant decrease in the production of IFN‐gamma compared with control mice (p = 0.001). IL‐10 production was also enhanced in splenic mononuclear cells in sesame oil‐treated mice. The ratio of IFN‐gamma to IL‐10 in sesame oil‐treated EAE mice was significantly less than in non‐treated EAE mice (p = 0.01). This report indicates that sesame oil therapy protected mice from developing EAE by reducing IFN‐gamma secretion. Thus, sesame oil treatment may be effective in MS patients by immunomodulating the Th1 immune response. Copyright © 2011 John Wiley & Sons, Ltd.
Assessment of numerical weather forecasts against observations from Cardington: seasonal diurnal cycles of screen‐level and surface temperatures and surface fluxes
Authors: Edwards J. M. , McGregor J. R. , Bush M. R. , Bornemann F. J.
Published: April 2011

The performance of numerical weather forecasts made with the Met Office Unified Model is evaluated using near‐surface measurements made at a comprehensively instrumented site over the course of the annual cycle, with the aim of characterizing the forecasting system's generic behaviour in the surface layer. The study is focused on the seasonal diurnal cycles of the screen‐level and surface temperatures and the surface flux budget.

High‐resolution versions of the model simulate seasonal composite diurnal cycles of the screen temperature to an accuracy of about 1 K, but appear to show a cold bias in the surface skin temperature by day and a warm bias at night, while underestimating the magnitude of the difference in temperature between the screen level and the surface, particularly in conditions of light winds and strong surface cooling.

The consistency of the measured surface fluxes is assessed by deriving the full annual cycle of the monthly mean atmospheric surface fluxes. The measured surface flux budget at this site is closed to an accuracy better than 5 W m−2. Comparison of the modelled and measured fluxes shows that in spring and summer the modelled downward shortwave fluxes are too large, while the latent heat fluxes are overestimated. Copyright © 2011 British Crown Copyright. Published by John Wiley & Sons Ltd.
The ERA‐Interim reanalysis: configuration and performance of the data assimilation system
Authors: Dee D. P. , Uppala S. M. , Simmons A. J. , Berrisford P. , Poli P. , Kobayashi S. , Andrae U. , Balmaseda M. A. , Balsamo G. , Bauer P. , Bechtold P. , Beljaars A. C. M. , van de Berg L. , Bidlot J. , Bormann N. , Delsol C. , Dragani R. , Fuentes M. , Geer A. J. , Haimberger L. , Healy S. B. , Hersbach H. , Hólm E. V. , Isaksen L. , Kållberg P. , Köhler M. , Matricardi M. , McNally A. P. , Monge‐Sanz B. M. , Morcrette J.‐J. , Park B.‐K. , Peubey C. , de Rosnay P. , Tavolato C. , Thépaut J.‐N. , Vitart F.
Published: April 2011

ERA‐Interim is the latest global atmospheric reanalysis produced by the European Centre for Medium‐Range Weather Forecasts (ECMWF). The ERA‐Interim project was conducted in part to prepare for a new atmospheric reanalysis to replace ERA‐40, which will extend back to the early part of the twentieth century. This article describes the forecast model, data assimilation method, and input datasets used to produce ERA‐Interim, and discusses the performance of the system. Special emphasis is placed on various difficulties encountered in the production of ERA‐40, including the representation of the hydrological cycle, the quality of the stratospheric circulation, and the consistency in time of the reanalysed fields. We provide evidence for substantial improvements in each of these aspects. We also identify areas where further work is needed and describe opportunities and objectives for future reanalysis projects at ECMWF. Copyright © 2011 Royal Meteorological Society
Highly correlated calculations using optimized virtual orbital space with controlled accuracy. Application to counterpoise corrected interaction energy calculations
Authors: Kraus Michal , Pitoňák Michal , Hobza Pavel , Urban Miroslav , Neogrády Pavel
Published: April 2011

In this work, we investigate the correlation between error introduced by truncation of optimized virtual orbital space (OVOS) on the MP2 level (YMP2) with the error of the post‐MP2 contributions, such as the CCSD‐MP2 (i.e., YΔCCSD), CCSD(T)‐MP2 (i.e., YΔCCSD(T)), or the (T) separately. We found a correlation between the YMP2 and several other quantities, such as the percent of recovered optimization functional value in the truncated OVOS (OF%), or the aforementioned YΔCCSD, YΔCCSD(T), Y(T), which is to good approximation linear in the logarithmic scale. These correlations open a possibility to control the accuracy of the post‐MP2 calculations in the truncated OVOS, because the YMP2 and the OF% are easily obtained, almost as a byproduct of the virtual orbital optimization. According to the results present in this work, knowledge of the YMP2 or the OF% allows us to safely estimate the order of magnitude of the error of the post‐MP2 corrections. To keep the accuracy of, for instance, CCSD(T) correlation energy calculated in the truncated OVOS within 1.10−5 − 1.10−6 Hartree error bars, we can typically reduce only a few percent of the OVOS, although this value increases slightly with enlarging the atomic orbital (AO) basis set and the number of inactive occupied orbitals. Still, even such a modest reduction can save more then a half of the computation time, compared with calculations in the full VOS. The situation is, however, much more favourable in case of counterpoise (CP) corrected calculations of interaction energy, where this methodology enables safe truncation of significant part of OVOS of monomers, resulting from the presence of the ghost AO. Dimension of such truncated OVOS essentially corresponds to CP‐uncorrected calculations, thus leads to more than an order of magnitude speedup of calculation of monomers. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Experimental and theoretical investigation of the molecular and electronic structure of N′‐benzylidene‐N‐[4‐(3‐methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐chloro‐acetic acid hydrazide
Authors: Demir Sibel , Dinçer Muharrem , Çukurovali Alaaddin , Yilmaz ibrahim
Published: April 2011

The title compound, N′‐benzylidene‐N‐[4‐(3‐methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐chloro‐acetic acid hydrazide, has been synthesized and characterized by elemental analysis, IR, 1H and 13C NMR, and X‐ray single crystal diffraction. The compound crystallizes in the orthorhombic space group P 21 21 21 with a = 5.8671 (3) Å, b = 17.7182 (9) Å, and c = 20.6373 (8) Å. Moreover, the molecular geometry from X‐ray experiment, the molecular geometry, vibrational frequencies, and gauge‐including atomic orbital 1H and 13C chemical shift values of the title compound in the ground state have been calculated by using the Hartree–Fock and density functional methods (B3LYP) with 6‐31G(d) and 6‐31G(d,p) basis sets. The results of the optimized molecular structure are exhibited and compared with the experimental X‐ray diffraction. Besides, molecular electrostatic potential, Frontier molecular orbitals, and thermodynamic properties of the title compound were determined at B3LYP/6‐31G(d) levels of theory. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Temperature dependence of the rate constant of ionic analogs of H + H2 → H2 + H reaction by quantum instanton method
Authors: Buchowiecki Marcin
Published: April 2011

Rate constant ratios k(T)/k(1,500K) for two symmetrical reactions H− + H2 → H2 + H− and H+ + H2 → H2 + H+ are reported. Direct method based on quantum instanton approximation for evaluation of the temperature dependence of the quantum‐mechanical reaction rate constant is used. Implementation of the theory involves thermodynamic integration and path integral Monte Carlo method. Results of anionic case shows resemblance to neutral case, whereas cationic case is significantly different and below 1,000K rate constant shows strong deviation form linearity of Arrhenius plot due to high activation barrier. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
The potential role of self‐sampling for high‐risk human papillomavirus detection in cervical cancer screening
Authors: Schmeink Channa E. , Bekkers Ruud L. M. , Massuger Leon F. A. G. , Melchers Willem J. G.
Published: April 2011

High‐risk human papillomavirus (hr‐HPV) detection will become an important tool in the screening for cervical cancer. Self‐sampling is an inexpensive and well‐accepted method for HPV detection that will increase participation of nonresponders in current screening programs. Even more, because self‐collected samples are as good as physician‐collected samples for HPV detection, self‐sampling might be a suitable method for future primary cervical cancer screening. Copyright © 2011 John Wiley & Sons, Ltd.
How to control an infectious bead string: nucleosome‐based regulation and targeting of herpesvirus chromatin
Authors: Nevels Michael , Nitzsche Alexandra , Paulus Christina
Published: April 2011

Herpesvirus infections of humans can cause a broad variety of symptoms ranging from mild afflictions to life‐threatening disease. During infection, the large double‐stranded DNA genomes of all herpesviruses are transcribed, replicated and encapsidated in the host cell nucleus, where DNA is typically structured and manoeuvred through nucleosomes. Nucleosomes individually assemble DNA around core histone octamers to form ‘beads‐on‐a‐string’ chromatin fibres. Herpesviruses have responded to the advantages and challenges of chromatin formation in biologically unique ways. Although herpesvirus DNA is devoid of histones within nucleocapsids, nuclear viral genomes most likely form irregularly arranged or unstable nucleosomes during productive infection, and regular nucleosomal arrays resembling host cell chromatin in latently infected cells. Besides variations in nucleosome density, herpesvirus chromatin ‘bead strings’ undergo dynamic changes in histone composition and modification during the different stages of productive replication, latent infection and reactivation from latency, raising the likely possibility that epigenetic processes may dictate, at least in part, the outcome of infection and ensuing pathogenesis. Here, we summarise and discuss several new and important aspects regarding the nucleosome‐based mechanisms that regulate herpesvirus chromatin structure and function in infected cells. Special emphasis is given to processes of histone deposition, histone variant exchange and covalent histone modification in relation to the transcription from the viral genome during productive and latent infections by human cytomegalovirus and herpes simplex virus type 1. We also present an overview on emerging histone‐directed antiviral strategies that may be developed into ‘epigenetic therapies’ to improve current prevention and treatment options targeting herpesvirus infection and disease. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamic output feedback integral sliding mode control design for uncertain systems
Authors: Chang Jeang‐Lin
Published: April 2011

This paper addresses the problem of designing a dynamic output feedback sliding mode control algorithm for linear MIMO systems with mismatched parameter uncertainties along with disturbances and matched nonlinear perturbations. Once the system is in the sliding mode, the proposed output‐dependent integral sliding surface can robustly stabilize the closed‐loop system and obtain the desired system performance. Two types of mismatched disturbances are considered and their effects on the sliding mode are explored. By introducing an additional dynamics into the controller design, the developed control law can guarantee that the system globally reaches and is maintained on the sliding surface in finite time. Finally, the feasibility of the proposed method is illustrated by numerical examples. Copyright © 2011 John Wiley & Sons, Ltd.
Interconnected jumping time‐delay systems: Mode‐dependent decentralized stability and stabilization
Authors: Mahmoud Magdi S.
Published: April 2011

In this paper, we deal with the problems of mode‐dependent decentralized stability and stabilization with ℋ︁∞ performance for a class of continuous‐time interconnected jumping time‐delay systems. The jumping parameters are governed by a finite state Markov process and the delays are unknown time‐varying and mode‐dependent within interval. The interactions among subsystems satisfy quadratic bounding constraints. To characterize mode‐dependent local stability behavior, we employ an improved Lyapunov–Krasovskii functional at the subsystem level and express the stability conditions in terms of linear matrix inequalities (LMIs). A class of local decentralized state‐feedback controllers is developed to render the closed‐loop interconnected jumping system stochastically stable. Then, we extend the feedback strategy to dynamic observer‐based control and establish the stochastic stabilization via LMIs. It has been established that the developed results encompass several existing results as special cases which are illustrated by simulation of examples. Copyright © 2011 John Wiley & Sons, Ltd.
Adaptive output feedback control of uncertain nonlinear systems based on dynamic surface control technique
Authors: Liu Yan‐Jun , Wang Wei
Published: April 2011

An adaptive output feedback control approach is studied for a class of uncertain nonlinear systems in the parametric output feedback form. Unlike the previous works on the adaptive output feedback control, the problem of ‘explosion of complexity’ of the controller in the conventional backstepping design is overcome in this paper by introducing the dynamic surface control (DSC) technique. In the previous schemes for the DSC technique, the time derivative for the virtual controllers is assumed to be bounded. In this paper, this assumption is removed. It can be proven that the resulting closed‐loop system is stable in the sense that all the signals are semi‐global uniformly ultimately bounded and the system output tracks the reference signal to a bounded compact set. A simulation example is given to verify the effectiveness of the proposed approach. Copyright © 2011 John Wiley & Sons, Ltd.
Performance analysis for multi‐delay systems in finite frequency domains
Authors: Zhang Xiao‐Ni , Yang Guang‐Hong
Published: April 2011

This paper considers the problem of performance analysis for continuous‐time multi‐delay systems in finite frequency domains. Unlike the existing results about the performance analysis for time‐delay systems in the entire frequency range, this study is focused on examining the performances of time‐delay systems in finite frequency ranges. Based on a further generalization of the strict S‐procedure, a delay‐dependent sufficient condition for systems to satisfy performances in finite frequency intervals is developed in the framework of linear matrix inequality approach. Finally, the effectiveness of the proposed method is illustrated via some numerical examples. Copyright © 2011 John Wiley & Sons, Ltd.
Robust smart‐cards‐based user authentication scheme with user anonymity
Authors: Wu Shuhua , Zhu Yuefei , Pu Qiong
Published: April 2011

In this paper, we mainly investigate anonymous user authentication scheme using smart card. We first demonstrate security weaknesses still exist in two such schemes recently propose by Wang et al. and Tsai et al., respectively according to Wang et al.'s criteria. Thereafter, we propose an enhanced smart‐card‐based authentication scheme with user anonymity for providing all the admired requirements at the same time. Compared with the previous schemes, our scheme is yet efficient both in computation and communication cost. Moreover, we can prove the security of the proposed scheme in the random oracle model. Copyright © 2011 John Wiley & Sons, Ltd.
The breakage and damage of plasmid DNA photocatalized by TiO2/carbon nanotube composites
Authors: Li Song , Xiong Xinhong , Li Wenfeng
Published: April 2011

In this paper, the plasmid DNA was used as a target to evaluate the bioeffect of TiO2/Carbon Nanotube (CNT) composites. The conformational change and breakage of DNA induced by the composites were characterized by the integrated tools of electrochemistry, circular dichroism (CD), atomic force microscopy (AFM), and DNA electrophoresis. At the early stage of incubation, the DNA double helix conformation was substantially changed by TiO2/CNT composites. Both electrophoresis and electrochemistry results suggested the breakage and damage appeared on the native DNA molecules. When DNA was treated longer by TiO2/CNT, DNA molecules were broken into fragment. AFM images confirmed the process. The DNA damage was deemed to be a gradual process: supercoiled plasmid DNA was first damaged to nicked‐circle structure, then further to linear form, and then DNA fragment. Copyright © 2011 John Wiley & Sons, Ltd.
Dissolution of copper oxide by the ethanolamine and ammonium fluoride in aqueous solution
Authors: Kwang Ko Cheon , Lee Won Gyu
Published: April 2011

Dissolution properties of copper oxide in aqueous solutions containing ethanolamine and/or ammonium fluoride have been evaluated at various pH ranges. The dissolution rate was strongly affected by the pH of the solution. The solution of ammonium fluoride showed good properties for the dissolution of copper oxide in the range of acidic conditions, whereas the solution containing ethanolamine showed a dissolution property within the basic condition. A mixture solution of ethanolamine and ammonium fluoride displayed enhanced dissolution property of copper oxide at acidic and basic conditions only. An expected synergy effect on the dissolution rate and selectivity could not be produced through a mixture of ethanolamine and ammonium fluoride in an aqueous solution. Copyright © 2011 John Wiley & Sons, Ltd.
Universal Scaling of the Charge Transport in Large‐Area Molecular Junctions
Authors: Kronemeijer Auke J. , Katsouras Ilias , Huisman Eek H. , van Hal Paul A. , Geuns Tom C. T. , Blom Paul W. M. , de Leeuw Dago M.
Published: April 2011

Charge transport through alkanes and para‐phenylene oligomers is investigated in large‐area molecular junctions. The molecules are self‐assembled in a monolayer and contacted with a top electrode consisting of poly(3,4‐ethylenedioxythiophene)–poly(4‐styrenesulfonic acid) (PEDOT:PSS). The complete set of J(V,T) characteristics of both saturated and π‐conjugated molecules can be described quantitatively by a single equation with only two fit parameters. The derived parameters, in combination with a variation of the bulk conductivity of PEDOT:PSS, demonstrate that the absolute junction resistance is factorized with that of PEDOT:PSS.
Chitosan‐Functionalized Graphene Oxide as a Nanocarrier for Drug and Gene Delivery
Authors: Bao Hongqian , Pan Yongzheng , Ping Yuan , Sahoo Nanda Gopal , Wu Tongfei , Li Lin , Li Jun , Gan Leong Huat
Published: April 2011

The covalent functionalization of graphene oxide (GO) with chitosan (CS) is successfully accomplished via a facile amidation process. The CS‐grafted GO (GO–CS) sheets consist of about 64 wt.% CS, which imparts them with a good aqueous solubility and biocompatibility. Additionally, the physicochemical properties of GO–CS are studied. As a novel nanocarrier, GO–CS is applied to load a water‐insoluble anticancer drug, camptothecin (CPT), via π–π stacking and hydrophobic interactions. It is demonstrated that GO–CS possesses a superior loading capacity for CPT, and the GO–CS–CPT complexes show remarkably high cytotoxicity in HepG2 and HeLa cell lines compared to the pure drug. At the same time, GO–CS is also able to condense plasmid DNA into stable, nanosized complexes, and the resulting GO–CS/pDNA nanoparticles exhibit reasonable transfection efficiency in HeLa cells at certain nitrogen/phosphate ratios. Therefore, the GO–CS nanocarrier is able to load and deliver both anticancer drugs and genes.
Characterization of hello message exchange to estimate sensor node's neighborhood residual energy distribution in initialization phase
Authors: Fang Shudong , Berber Stevan Mirko , Swain Akshya Kumar
Published: April 2011

The paper characterizes the hello message exchange (HME) procedure for a sensor node to develop its neighborhood residual energy distribution in the initialization phase of a static wireless sensor network. Because of the lack of coordination on channel access in the initialization phase, hello messages from multiple nodes face a high risk of data collision in the exchange course. A discovery ratio is hereby defined to measure the sufficiency of the HME procedure. The discovery ratio is related to the precision of the parameter estimates for the probability density function of a node's neighborhood residual energy distribution. To achieve an arbitrarily high discovery ratio within a resolvable time interval, the HME procedure is implemented using Birthday protocol, which results in large node energy consumption. To overcome this flaw, a method termed carrier sensing mini‐slot algorithm is proposed to carry out the HME procedure. The time duration and the node energy consumption for the HME procedures based on the Birthday protocol and the carrier sensing mini‐slot algorithm, respectively, are theoretically analyzed and verified by simulations. Copyright © 2011 John Wiley & Sons, Ltd.
Cattle rancher and conservation agency personnel perceptions of wildlife management and assistance programs in Alabama, Florida, Georgia, and Mississippi
Authors: Willcox Adam S. , Giuliano William M.
Published: April 2011

Natural resource agencies in the United States continue to design and expand technical and financial assistance programs that benefit private landowners managing for wildlife. Cattle ranchers, one of the primary stakeholders, are well poised to benefit from these programs, especially if they can easily integrate wildlife management activities into cattle operations. A key component to implementing successful wildlife management programs on ranches is to understand how ranchers perceive wildlife management and assistance programs. It is also important that conservation agency personnel working with these ranchers are able to assess rancher perceptions of wildlife management accurately so they can tailor programs that meet rancher needs and foster strong working and interpersonal relationships. We surveyed 1,634 ranchers to understand their perceptions of wildlife benefits and problems, attitudes toward wildlife, and likeliness to participate in financial and technical assistance programs. We also surveyed 52 natural resource‐agency personnel regarding their perceptions of ranchers on similar topics, to allow for direct comparison of responses. Rancher and agency responses were similar for many wildlife benefits and attitudes toward wildlife, yet agency personnel overestimated rancher perceptions of wildlife problems and the economic benefits of wildlife enterprises. We suggest ways conservation agencies can improve current assistance programs for cattle ranchers based on both rancher and agency employee perceptions of wildlife management. This includes emphasizing programs that feature preferred species and better integrating wildlife management with routine cattle operations. © 2011 The Wildlife Society.
Interdisciplinarity and innovation dynamics. On convergence of research, technology, economy, and society
Authors: Mainzer Klaus
Published: April 2011

In the age of globalization, economic growth and the welfare of nations decisively depend on basic innovations. Therefore, education and knowledge is an important advantage of competition in highly developed countries with high standards of salaries, but raw material shortage. In the twenty-first century, innovations will arise from problem-oriented research, crossing over traditional faculties and disciplines. Therefore, we need platforms of interdisciplinary dialogue to choose transdisciplinary problems (e.g., environment, energy, information, health, welfare) and to cluster new portfolios of technologies. The clusters of research during the excellence initiative at German universities are examples of converging sciences. The integration of natural and engineering sciences as well as medicine can only be realized if the research training programs (e.g., graduate schools) generate a considerable added value in terms of multidisciplinary experience, international networking, scientific and entrepreneurial know-how, and personality development. The Carl von Linde-Academy is presented as an example of an interdisciplinary center of research and teaching at the Technical University of Munich.
L’utilisation du MSOME: expérience de six ans
Authors: Dumont M. , Junca A. -M. , Belloc S. , Cohen-Bacrie P. , Cohen-Bacrie M. , Menezo Y. , Benkhalifa M. , de Mouzon J. , Prisant N.
Published: April 2011

Introduction

L’analyse fine de la morphologie des spermatozoïdes à un grossissement de 6600 x, appelée MSOME (motile sperm organellar morphology examination) et appliquée en ICSI, a donné naissance à l’IMSI (intracytoplasmic morphologically selected sperm injection). Cette technique est proposée aux couples en échecs répétés d’implantation embryonnaire en ICSI, dans le but d’obtenir une grossesse évolutive.

Matériel et méthodes

L’étude concerne une cohorte observationnelle de 11535 ICSI pratiquées avec du sperme éjaculé frais, de janvier 2004 à juillet 2009. Parmi celles-ci, 2509 ont été réalisées avec IMSI. Les paramètres étudiés sont: le taux de clivage à J2 par ovocyte injecté, le taux de grossesses cliniques par ponction et le taux de fausses couches spontanées, en fonction du rang de la tentative et/ou de la qualité du sperme du bilan. Ces données ont été comparées entre l’ICSI et l’IMSI et les comparaisons ont été faites à l’aide de Chi2 et d’analyse de variance.

Résultats

Nous n’avons pas observé de différence significative entre l’ICSI et l’IMSI en termes de taux de clivage à J2 et taux de grossesses cliniques. Par contre, le taux de grossesses, en IMSI de rang 1, est significativement plus élevé en cas d’anomalie du sperme si on regroupe les tératozoospermies avec les oligozoospermies et les oligotératozoospermies (34,4 vs 27,1%, p = 0,02). De plus, si l’on regroupe les tératozoospermies et les oligotératozoospermies, le taux de fausses couches est plus faible en IMSI comparé à l’ICSI, de manière proche de la significativité (12,6% vs. 19,6%, p = 0,08).

Conclusion

En présence d’une tératozoospermie sévère, l’IMSI semble augmenter les taux de grossesses et diminuer les taux de fausses couches.
Ectomesenchymal chondromyxoid tumor of the anterior tongue: A rare case
Authors: Sengul Demet , Sengul Ilker , Ozdol Mehmet Umit , Astarci Muzeyyen Hesna , Ustun Huseyin
Published: April 2011

Ectomesenchymal chondromyxoid tumor is a rare tumor seen in the anterior dorsal aspect of the tongue. Diagnosis of this lesion without a prediagnosis clinically is made only with histopathological findings including the immunohistochemical examinations. However, diverse results are being reported in the literature with keratin staining. While glial fibrillary acid protein positiveness maintain being a fixed repeating feature, we emphasized for our case of a 28‐year‐old Caucasian woman having the findings of qualities supporting the ectomesenchymal origin of the mentioned tumor.