bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating Reliability on Fuel Cell Model Identification. Part I: A Design of Experiments Approach
Authors: Tsikonis L. , Van herle J. , Favrat D.
Published: November 2011

A model‐based Design of Experiments method was employed for the optimization of measurements on a solid oxide fuel cell (SOFC). Based on a simplified SOFC model, a variation of the D‐optimality was used as optimization criterion for the calculation of optimal experimental designs (determinant of the covariance matrix with weighting factors). Solutions for different numbers of design points were calculated and the behavior of optimization criteria as functions of the number of design points as well as of the number of repetitions of measurements was analyzed. A new type of graph was introduced which depicts the behavior of optimization criteria for constant number of measurements. This approach showed that, for constant numbers of measurements, the precision is higher and therefore the reliability in the cell's model identification is improved when repeated measurements of a small set of optimal design points are effectuated, instead of many different measurements. Finally, a sensitivity analysis was performed showing the influence of the parameter values on the values of the optimization criterion and the optimal measurements.

The used methodology and its theoretical conclusions may be used as a basis for development of diagnostics tools or filtering existing data for optimal parameter estimations.
Effect of Ce‐Doping on the Electrical and Electrocatalytical Behavior of La/Sr Chromo‐Manganite Perovskite as New SOFC Anode
Authors: Lay E. , Benamira M. , Pirovano C. , Gauthier G. , Dessemond L.
Published: November 2011

The effect of cerium substitution on the electrical and electrochemical characteristics of a new anode material La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) was examined by synthesizing CexLa0.75–xSr0.25Cr0.5Mn0.5O3 for x = 0–0.375). From x = 0–0.25, the structure is rhombohedral (S.G. R‐3c), and with a higher cerium content (x = 0.375) it becomes cubic (S.G. Pm‐3m). These materials are stable in the operating conditions of an SOFC anode. CexLa0.75–xSr0.25Cr0.5Mn0.5O3 and LSCM materials are p‐type semi‐conductors. Cerium substitution improves the conductivity in neutral atmosphere from 18.3 to 35.4 S cm–1 for x = 0 and 0.375, respectively, at 1,173 K. In reducing conditions, the conductivity is not influenced by cerium substitution, and it is about 1 S cm–1 at 1,173 K. High temperature XRD shows that structure becomes cubic at 1,073 K in operating (reducing) conditions. Cerium substitution positively enhances the electrochemical behavior, as proved by studying the properties of dense cone‐shaped electrodes.
Postoperative spindle cell nodule after thyroidectomy: A case mimicking recurrence with anaplastic transformation of thyroid cancer
Authors: Kim Sun Wook , Oh Young Lyun , Choi Joon Young , Lee Ji In , Chung Jae Hoon , Kim Jee Soo
Published: November 2011

Background

Here, we report a case of a postoperative spindle cell nodule that mimicked recurrence with anaplastic transformation after thyroidectomy.

Methods

The course of the disease is described. The mass was studied morphologically and immunohistochemically.

Results

A 31‐year‐old woman underwent total thyroidectomy for papillary thyroid carcinoma. A mass suspected of recurrence was found 14 months later and caused dysphagia and dyspnea. An 18F‐fluorodeoxyglucose positron emission tomographic (18F‐FDG‐PET) scan showed a lesion with high uptake; however, a fine‐needle aspiration biopsy (FNAB) was inconsistent with recurrent cancer. The mass was resected and was composed of elongated spindle cells, with eosinophilic cytoplasm within a myxoid background. Immunohistochemical staining was strongly positive for vimentin, focally positive for smooth muscle actin, desmin, and p53, and negative for cytokeratin AE1/AE3, Cam5.2, epithelial membrane antigen (EMA), and anaplastic lymphoma kinase (ALK‐1).

Conclusion

Although postoperative spindle cell nodules are rare after thyroid surgery, it should be considered in the differential diagnosis for recurrent masses at the operative site. Head Neck, 2013
Thyroid cartilage invasion in early‐stage squamous cell carcinoma involving the anterior commissure
Authors: Hartl Dana M. , Landry Guillaume , Hans Stéphane , Marandas Patrick , Casiraghi Odile , Janot François , Brasnu Daniel F.
Published: November 2011

Background

Anterior commissure (AC) carcinoma is in close proximity to the thyroid cartilage. Our objective was to evaluate risk factors for thyroid cartilage invasion.

Methods

This was a retrospective study of tumors involving the AC treated by open surgery. Tumor stage, extensions, vocal fold (VF) mobility, CT scan, and pathologic cartilage status were recorded.

Results

Ninety‐four patients with clinical T (cT) classifications cT1b (44%), cT2 (50%), and cT3 (6%) were included. The incidence of thyroid cartilage invasion was 8.5%, significantly related to VF mobility, with invasion in 31% versus 5% with normal mobility (p = .002). Sensitivity, specificity, and positive and negative predictive values for decreased VF mobility were 50%, 90%, 31%, and 95%, respectively. After a median follow‐up of 49 months, there was no difference in local control between tumors with or without cartilage invasion.

Conclusions

For these tumors involving the AC, VF mobility was the only significant factor related to thyroid cartilage invasion and should be taken into consideration when planning surgery. © 2011 Wiley Periodicals, Inc. Head Neck, 2011
Cytomegalovirus-specific T-cell reactivity in biliary atresia at the time of diagnosis is associated with deficits in regulatory T cells
Authors: Brindley Stephen M. , Lanham Allison M. , Karrer Frederick M. , Tucker Rebecca M. , Fontenot Andrew P. , Mack Cara L.
Published: November 2011

Biliary atresia (BA) is a progressive, inflammatory cholangiopathy that culminates in fibrosis of extrahepatic and intrahepatic bile ducts. A leading theory on the pathogenesis of BA is that the bile duct damage is initiated by a virus infection, followed by a bile duct-targeted autoimmune response. One mechanism of autoimmunity entails a diminished number or function of regulatory T cells (Tregs). The aim of this study was to identify potential virus-specific liver T cells from infants with BA at the time of diagnosis, implicating the virus involved in early bile duct damage. A subaim was to determine if the presence of virus infection was associated with quantitative changes in Tregs. Liver T cells from BA and control patients were cultured with antigen-presenting cells in the presence of a variety of viral or control proteins. 56% of BA patients had significant increases in interferon-gamma-producing liver T cells in response to cytomegalovirus (CMV), compared with minimal BA responses to other viruses or the control group CMV response. In addition, a positive correlation between BA plasma CMV immunoglobulin M (IgM) and liver T-cell CMV reactivity was identified. Investigation of peripheral blood Tregs revealed significant deficits in Treg frequencies in BA compared with controls, with marked deficits in those BA patients who were positive for CMV. Conclusion: Liver T-cell responses to CMV were identified in the majority of BA patients at diagnosis, suggesting perinatal CMV infection as a plausible initiator of bile duct damage. Deficiency of Tregs in BA implies decreased inhibition of inflammation and autoreactivity, potentially allowing for exaggerated bile duct injury. (Hepatology 2012)
Loss of microRNA 122 expression in patients with hepatitis B enhances hepatitis B virus replication through cyclin G1-modulated P53 activity
Authors: Wang Saifeng , Qiu Lipeng , Yan Xiaoli , Jin Wensong , Wang Yanzhong , Chen Lizhao , Wu Erjie , Ye Xin , Gao George F. , Wang Fusheng , Chen Yu , Duan Zhongping , Meng Songdong
Published: November 2011

Hepatitis B virus (HBV) causes chronic infection in about 350 million people worldwide. Given the important role of the most abundant liver-specific microRNA, miR-122, in hepatic function and liver pathology, here we investigated the potential role and mechanism of miR-122 in regulating HBV replication. We found that miR-122 expression in liver was significantly down-regulated in patients with HBV infection compared with healthy controls, and the miR-122 levels were negatively correlated with intrahepatic viral load and hepatic necroinflammation. The depletion of endogenous miR-122 by its antisense inhibitor led to enhanced HBV replication, whereas overexpression of miR-122 by transfection of mimic or its expression vector inhibited viral production. We next identified cyclin G1 as an miR-122 target from multiple candidate target genes that are involved in the regulation of HBV replication. Overexpression and knockdown studies both showed that cyclin G1 regulated viral replication in HBV transfected cells. We also observed that cyclin G1 expression was up-regulated in HBV-infected patients, and cyclin G1 levels were inversely associated with miR-122 expression in liver tissues. Using coimmunoprecipitation, a luciferase reporter system, and electrophoretic mobility shift assay, we further demonstrated that cyclin G1 specifically interacted with p53, and this interaction blocked the specific binding of p53 to HBV enhancer elements and simultaneously abrogated p53-mediated inhibition of HBV transcription. Finally, we show that miR-122 suppressed HBV replication in p53 wildtype cells but not in null isogenic cells.

Conclusion:

miR-122 down-regulates its target cyclin G1, and thus interrupts the interaction between cyclin G1 and p53 and abrogates p53-mediated inhibition of HBV replication. Our work shows that miR-122 down-regulation induced by HBV infection can impact HBV replication and possibly contribute to viral persistence and carcinogenesis.
Meander hydrodynamics initiated by river restoration deflectors
Authors: Zhou Tian , Endreny Ted
Published: November 2011

River restoration projects have installed j‐hook deflectors along the outer bank of meander bends to reduce hydraulic erosion, and in this study we use a computational fluid dynamics (CFD) model to document how these deflectors initiate changes in meander hydrodynamics. We validated the CFD with streamwise and cross‐channel bankfull velocities from a 193° meander bend flume (inlet at 0°) with a fixed point bar and pool equilibrium bed but no j‐hooks, and then used the CFD to simulate changes to flow initiated by bank‐attached boulder j‐hooks (1st attached at 70°, then a 2nd at 160°). At bankfull and half bankfull flow the j‐hooks flattened transverse water surface slopes, formed backwater pools upstream of the boulders, and steepened longitudinal water slopes across the boulders and in the conveyance region off the mid‐channel boulder tip. Streamwise velocity and mass transport jets upstream of the j‐hooks were stilled, mid‐channel jets were initiated in the conveyance region, eddies with a cross‐channel axis formed below boulders, and eddies with a vertical axis were shed into wake zones downstream of the point bar and outer bank boulders. At half bankfull depth conveyance region flow cut toward the outer bank downstream of the j‐hook boulders and the secondary circulation cells were reshaped. At bankfull depth the j‐hook at 160° was needed to redirect bank‐impinging flow sent by the upstream j‐hook. The hooked boulder tip of both j‐hooks funneled surface flow into mid‐channel plunging jets, which reversed the secondary circulation cells and initiated 1 to 3 counter rotating cells through the entire meander. The main outer bank collision zone centered at 50° without the j‐hook was moved by the j‐hook to within and just beyond the 70° j‐hook boulder region, which displaced other mass transport zones downstream. J‐hooks re‐organized water surface slopes, streamwise and cross‐channel velocities, and mass transport patterns, to move shear stress from the outer bank and into the conveyance and mid‐channel zones at bankfull flow. At half bankfull flows a patch of high shear re‐attached to the outer bank below the downstream j‐hook. J‐hook geometry and placement within natural meanders can be analyzed with CFD models to help restoration teams reach design goals and understand hydraulic impacts. Copyright © 2011 John Wiley & Sons, Ltd.
Estimating evapotranspiration with land data assimilation systems
Authors: Peters‐Lidard Christa D. , Kumar Sujay V. , Mocko David M. , Tian Yudong
Published: November 2011

Advancements in both land surface models (LSMs) and land surface data assimilation, especially over the last decade, have substantially advanced the ability of land data assimilation systems (LDASs) to estimate evapotranspiration (ET). This article provides a historical perspective on international LSM intercomparison efforts and the development of LDASs, both of which have improved LSM ET skill. In addition, an assessment of ET estimates for current LDASs is provided along with current research that demonstrates improvement in LSM ET estimates due to assimilating satellite‐based soil moisture products. Using the Ensemble Kalman Filter in the Land Information System, we assimilate both NASA and Land Parameter Retrieval Model soil moisture products into the Noah LSM Version 3.2 with the North American LDAS Phase 2 (NLDAS‐2), forcing to mimic the NLDAS‐2 configuration. Through comparisons with two global reference ET products, one based on interpolated flux tower data and one from a new satellite ET algorithm, over the NLDAS‐2 domain, we demonstrate improvement in ET estimates only when assimilating the LPRM soil moisture product. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of conditional parameterization on performance of rainfall‐runoff model regarding hydrologic non‐stationarity
Authors: Luo Jiangmei , Wang Enli , Shen Shuanghe , Zheng Hongxing , Zhang Yongqiang
Published: November 2011

Better parameterization of a hydrological model can lead to improved streamflow prediction. This is particularly important for seasonal streamflow forecasting with the use of hydrological modelling. Considering the possible effects of hydrologic non‐stationarity, this paper examined ten parameterization schemes at 12 catchments located in three different climatic zones in east Australia. These schemes are grouped into four categories according to the period when the data are used for model calibration, i.e. calibration using data: (1) from a fixed period in the historical records; (2) from different lengths of historical records prior to prediction year; (3) from different climatic analogue years in the past; and (4) data from the individual months. Parameterization schemes were evaluated according to model efficiency in both the calibration and verification period. The results show that the calibration skill changes with the different historic periods when data are used at all catchments. Comparison of model performance between the calibration schemes indicates that it is worth calibrating the model with the use of data from each individual month for the purpose of seasonal streamflow forecasting. For the catchments in the winter‐dominant rainfall region of south‐east Australia, a more significant shift in rainfall‐runoff relationships at different periods was found. For those catchments, model calibration with the use of 20 years of data prior to the prediction year leads to a more consistent performance. Copyright © 2011 John Wiley & Sons, Ltd.
On the classification of weighing matrices and self‐orthogonal codes
Authors: Harada Masaaki , Munemasa Akihiro
Published: November 2011

We provide a classification method of weighing matrices based on a classification of self‐orthogonal codes. Using this method, we classify weighing matrices of orders up to 15 and order 17, by revising some known classification. In addition, we give a revised classification of weighing matrices of weight 5. A revised classification of ternary maximal self‐orthogonal codes of lengths 18 and 19 is also presented. © 2011 Wiley Periodicals, Inc. J Combin Designs 20:40–57, 2012
Reversible and DRAD difference sets in
Authors: Webster Jordan D.
Published: November 2011

The existence of Hadamard difference sets has been a central question in design theory. Reversible difference sets have been studied extensively. Dillon gave a method for finding reversible difference sets in groups of the form (C)2. DRAD difference sets are a newer concept. Davis and Polhill showed the existence of DRAD difference sets in the same groups as Dillon. This article determines the existence of reversible and DRAD difference sets in groups of the form (C)3. These are the only abelian 2‐groups outside of direct products of C4 and (C)2 known to contain reversible and DRAD difference sets. © 2011 Wiley Periodicals, Inc. J Combin Designs 20:58–67, 2012
Perineural cysts resembling complex cystic adnexal masses on transvaginal sonography
Authors: Saboo Sachin S. , Di Salvo Donald
Published: November 2011

Perineural cysts may be discovered incidentally on pelvic sonography and can easily mimic more common gynecologic masses. We report the complex cystic adnexal mass like appearance of these incidentally noted cysts which mimicked malignancy on sonography in a postmenopausal female, with stage I breast cancer and vaginal spotting. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound 2013
Repeatability and reproducibility of ultrasonographic measurement of carotid intima thickness
Authors: Lau Kar‐Ho , Fung Ying‐Keung , Cheung Yuk‐Ting , Tsang Wing‐Keung , Ying Michael
Published: November 2011

Purpose.

To evaluate the repeatability and reproducibility of intima thickness (IT) measurements at different sites along the common carotid artery and compare with intima–media thickness (IMT) measurements.

Methods.

Ultrasound examinations of common carotid artery were performed in 30 healthy subjects and 20 patients with diabetes mellitus. Carotid IT and IMT were measured at 10 mm, 13 mm, and 16 mm upstream from the carotid bulb. Each subject was scanned by three operators to evaluate inter‐operator reproducibility. Each operator scanned the subjects twice to evaluate intra‐operator repeatability. Inter‐equipment reproducibility of the measurements was evaluated.

Results.

The inter‐operator reproducibility for measuring carotid IT at the three sites was 81.5%, 81.9% and 69.1%, respectively, slightly lower than carotid IMT measurement (89.7%, 86.5%, 75.2%, respectively). The intra‐operator repeatability for carotid IT measurement at the three sites ranged 76.9–89.5%, 67.4–90.3%, and 55.2–70.5%, respectively, and was lower than for IMT measurement (86.5–96.9%, 87.6–95.7%, 79.9–86.5%, respectively). The inter‐equipment reproducibility of IMT (75.7–86.6%) was slightly better than for IT measurement (71.4–75.9%).

Conclusions.

Ultrasonographic measurement of carotid IT is repeatable and reproducible, although not as good as IMT. Measurements preformed 10 mm to 13 mm upstream from the carotid bulb yield more repeatable and reproducible results. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound 40:79–84, 2012
On the hamiltonicity of line graphs of locally finite, 6‐edge‐connected graphs
Authors: Brewster Richard C. , Funk Daryl
Published: November 2011

The topological approach to the study of infinite graphs of Diestel and KÜhn has enabled several results on Hamilton cycles in finite graphs to be extended to locally finite graphs. We consider the result that the line graph of a finite 4‐edge‐connected graph is hamiltonian. We prove a weaker version of this result for infinite graphs: The line graph of locally finite, 6‐edge‐connected graph with a finite number of ends, each of which is thin, is hamiltonian.
Synthesis and biological activities of some new thiazolidine derivatives containing pyrazole ring system
Authors: Nishida Sho , Maruoka Hiroshi , Yoshimura Yuki , Goto Takao , Tomita Ryoko , Masumoto Eiichi , Okabe Fumi , Yamagata Kenji , Fujioka Toshihiro
Published: November 2011

As a part of systematic investigation of synthesis and biologically active compounds of thiazolidine (TZD) derivatives containing pyrazole ring system, several new pyrazole–TZD derivatives 8a, 8b, 8c, 8d and 9a, 9b, 9c, 9d have been synthesized. Compounds 8a, 8b, 8c, 8d were prepared from N‐substituted TZDs 6a, 6b, 6c, 6d and 1H‐pyrazole‐4‐carboxaldehyde 7 by Knoevenagel‐type reaction. Treatment of 8a, 8b, 8c, 8d with sodium hydride at room temperature caused dimerization reaction to afford the corresponding spirocompounds 9a, 9b, 9c, 9d. All the synthesized compounds were characterized by spectroscopic analysis. In vitro, the synthesized compounds 8a, 8b, 8c, 8d and 9a, 9b, 9c, 9d were tested for their growth inhibitory activity in A549 lung cancer, B16F10 murine melanoma, and HeLa human uterine carcinoma cells and for their differentiation of 3T3‐L1 preadipocytes to adipocytes. The results showed that compound 8c possessed growth inhibitory effect of B16F10 cells (IC50 = 27 μM) and compounds 9c, 9d had induction effect on the differentiation of 3T3‐L1 preadipocytes. J. Heterocyclic Chem., (2011).
Fast estimation of RL‐loaded microelectronic interconnections delay for the signal integrity prediction
Authors: Ravelo Blaise , Eudes Thomas
Published: November 2011

This article presents a modelling method of the signal delays induced by microelectronic interconnections regarding RL impedance load. The method proposed is based on the RLC model of the transmission lines (TL) extracted from the equivalent S parameters. Formulation for estimating the interconnection propagation delay is established according to the behaviour of the TL unit step responses. The second order model is validated with a microstrip interconnect prototype with simulations and measurements in frequency and time domains. The developed propagation delay model was validated with SPICE computations. For that, a transient simulation was performed by considering input signals corresponding to high‐speed data of some Gbits/s. Then, accurate results were found for interconnections with different lengths in order of millimetre and also by varying the load values. It was shown that the computed 50% propagation delays present of relative errors about 5%. Copyright © 2011 John Wiley & Sons, Ltd.
Arsenic mobilization in rice (Oryza sativa) and its accumulation in the grains
Authors: Bogdan Katja , Schenk Manfred K.
Published: November 2011

Flooded rice (Oryza sativa L.) may contain high arsenic (As) concentrations compared to other grain crops. For the development of measures to reduce the As concentration of rice grains, knowledge about the mobility of As within the rice plant is required. Therefore, to investigate the mobilization of As within the plant, rice was grown in nutrient solution and exposed to As either before flowering, after flowering, or continuously until maturity. Furthermore, rice was grown in four soils under greenhouse and field conditions and the time course of As accumulation in grains during the grain‐filling period was investigated. When grown in nutrient solution, As removal at flowering did not reduce As concentrations in polished rice compared to plants supplied with As continuously or after flowering. Plants that received As only after flowering had the same As concentrations in shoot and bran as plants receiving As only before flowering. However, continuous As supply resulted in doubling of As concentrations in both plant parts. In contrast to grain and shoot, the As concentration in the root decreased after As removal compared to the treatments receiving As only after flowering or continuously. The observations indicate that As was mobilized from root or shoot to the grain and that it was accumulated in the grain, although it was not available in nutrient solution during the grain‐filling period. In soil experiments, the 1000‐grain weight increased up to 2 weeks before harvest in the field as well as in the greenhouse. The As concentration in rice grain was constant during the whole grain‐filling period. It was at a similar level under field and greenhouse conditions, and its variation among soils was in the same order indicating that soil was the decisive factor for As concentration in grains. Our results suggest that temporary cultural measures during the cultivation period, for example drainage, might be ineffective because of the mobilization capacity within the rice plant. Moreover, harvest before final maturity of grains would not reduce the As concentration since it remained constant during the grain‐filling period.
A qualitative study of U.S. veterans' reasons for seeking Department of Veterans Affairs disability benefits for posttraumatic stress disorder
Authors: Sayer Nina A. , Spoont Michele , Murdoch Maureen , Parker Louise E. , Hintz Samuel , Rosenheck Robert
Published: November 2011

Posttraumatic stress disorder (PTSD) is the most prevalent compensable mental disorder within the U.S. Department of Veterans Affairs disability system and the number of veterans with PTSD service‐connected disability has increased steadily over the past decade. An understanding of the reasons veterans apply for PTSD disability status may inform interpretation of this increase and policies and interventions to assist veterans with military‐related PTSD. The authors conducted an exploratory qualitative study to describe the reasons veterans seek PTSD disability benefits and explored differences between those who served in different military service eras. They gathered data through in‐depth interviews with 44 purposefully selected U.S. veterans, and conducted content analysis of transcribed interviews using inductive and deductive analysis with constant comparison. Participants described 5 interrelated categories of reasons for seeking PTSD disability benefits, including 3 internal factors (tangible need, need for problem identification or clarification, beliefs that justify/legitimize PTSD disability status) and 2 external factors (encouragement from trusted others and professional assistance). There were no major differences by service era. Findings may help policy makers, providers, and researchers understand what veterans hope to achieve through PTSD disability and the instrumental role of social networks and government systems in promoting the pursuit of PTSD disability status.
Enhanced Biomimetic Performance of Ionic Polymer–Metal Composite Actuators Prepared with Nanostructured Block Ionomers
Authors: Vargantwar Pruthesh H. , Roskov Kristen E. , Ghosh Tushar K. , Spontak Richard J.
Published: November 2011

Ionic polymer–metal composites (IPMCs) represent an important class of stimuli‐responsive polymers that are capable of bending upon application of an electric potential. Conventional IPMCs, prepared with Nafion and related polyelectrolytes, often suffer from processing challenges, relatively low actuation levels and back relaxation during actuation. In this study, we examine and compare the effects of fabrication and solvent on the actuation behavior of a block ionomer with a sulfonated midblock and glassy endblocks that are capable of self‐organizing and thus stabilizing a molecular network in the presence of a polar solvent. Unlike Nafion, this material can be readily dissolved and cast from solution to yield films that vary in thickness and exhibit enormous solvent uptake. Cycling the initial chemical deposition of Pt on the surfaces of swollen films (the compositing process) increases the extent to which the electrodes penetrate the films, thereby improving contact along the polymer/electrode interface. The maximum bending actuation measured from IPMCs prepared with different solvents is at least comparable, but is often superior, to that reported for conventional IPMCs, without evidence of back relaxation. An unexpected characteristic observed here is that the actuation direction can be solvent regulated. Our results confirm that this block ionomer constitutes an attractive alternative for use in IPMCs and their associated applications.
Synthesis of Clicked Imidazolium‐Containing Biosourced Copolymers and Application in Carbon Nanotube Dispersion
Authors: Mincheva Rosica , Meyer Franck , Verge Pierre , Raquez Jean‐Marie , Billiet Leen , Du Prez Filip , Dubois Philippe
Published: November 2011

New polyesters incorporating a variable quantity of imidazolium rings along the backbone are synthesized by Huisgen 1,3‐dipolar cycloaddition (“click” reaction). Subsequently, the imidazolium‐grafted copolymers reveal an efficient dispersing ability toward the carbon nanotubes (CNTs) through supramolecular interactions in organic media. Interestingly, these compounds offer a simple and reliable strategy to control the quantity of dispersed CNTs as a function of imidazolium content. This approach is particularly suitable for the elaboration of biosourced and biodegradable materials based on poly(butylene succinate) with high‐performance properties.
Instability of syllable repetition in patients with spinocerebellar ataxia and Parkinson's disease
Authors: Schmitz‐Hübsch Tanja , Eckert Oleksandr , Schlegel Uwe , Klockgether Thomas , Skodda Sabine
Published: November 2011

Background:

The aim of the current study was to test the hypothesis of a fundamental impairment of vocal pacing in patients with spinocerebellar ataxia and Parkinson's disease.

Methods:

Thirty‐one patients with spinocerebellar ataxia, 42 patients with Parkinson's disease, and 43 healthy controls had to repeat a single syllable at a self‐chosen isochronous pace. The coefficient of variance for interval length and the change in interval length with successive utterances were used to describe pace stability.

Results:

Ataxic and parkinsonian patients both showed a significant instability of vocal pace performance. Ataxic speakers featured difficulties in keeping the pace immediately from the beginning of the task, whereas parkinsonian patients accelerated the pace in the course of the performance. The results support differential roles of cerebellar and basal ganglia pathways in motor speech performance.

Conclusions:

Cerebellar function may be required for the general precision of interval timing, whereas basal ganglia rather serve to maintain rhythm stability over time. © 2011 Movement Disorder Society
Development of single‐stage and doherty GaN‐based hybrid RF power amplifiers for quasi‐constant envelope and high peak to average power ratio wireless standards
Authors: Moreno Jorge , Fang Jie , Quaglia Roberto , Camarchia Vittorio , Pirola Marco , Ghione Giovanni
Published: November 2011

This article describes the design, realization, and characterization of a set of hybrid medium‐power RF power amplifiers, based on a commercial packaged GaN HEMT and developed through a low‐cost microstrip process. Two different design solutions suitable for wireless applications are presented: the first, intended for a constant envelope modulation (with reference to the GSM standard) is a Class F amplifier exhibiting at 900 MHz an efficiency of 72% with an output power of 37.5 dBm; the second, optimized for nonconstant envelope signals with high dynamics (with reference to the UMTS WCDMA standard) is a Doherty amplifier showing, at 2.14 GHz, an efficiency higher than 40% at 6 dB of output power back‐off with a maximum output power of 40 dBm. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:206–210, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26459
Miniaturized microstrip wilkinson power divider with capacitor loading
Authors: He Jun , Feng Chen Zhao , Hai Yang Bao , Ying Xiong Mei
Published: November 2011

A novel miniaturized microstrip Wilkinson power divider with capacitor loading is presented in this article. The new divider not only effectively reduces the occupied area to 45% of the conventional one at 1.0 GHz, but also has good harmonic suppression performance. Furthermore, the new structure has only two variable parameters and can be easily designed. The design is validated both by simulation and measurement. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:61–63, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26484
A broadband antenna using the modified ground plane with a complementary split ring resonator for 5‐GHz WLAN band‐notched performance
Authors: Kim Jangyeol , Kim Nam , Lee Seungwoo
Published: November 2011

In this article, a new configuration of a broadband antenna is proposed.The designed antenna is an elliptical monopole antenna with a complementary split ring resonator structure that is inserted in the ground plane for rejecting the 5‐GHz WLAN band (5.15–5.35 and 5.725–5.825 GHz). In addition, impedance matching technique implemented by rectangular slot applied to the ground plane is suggested. The technique can be an effective method to achieve the wider bandwidth. The designed antenna shows that a VSWR less than 2 was satisfied with a resonant frequency in the range of 2.67–12 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:6–3, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26512
Improved enrichment and proteomic identification of outer membrane proteins from a Gram‐negative bacterium: Focus on Caulobacter crescentus
Authors: Cao Yuan , Johnson Helen M. , Bazemore‐Walker Carthene R.
Published: November 2011

Efforts to characterize proteins found in the outer membrane (OM) of Gram‐negative bacteria have been steadily increasing due to the promise of expanding our understanding of fundamental bacterial processes such as cell adhesion or cell wall biogenesis as well as the promise of finding potential vaccine‐ or drug‐targets for virulent bacteria. We have developed a mass spectrometry‐compatible experimental strategy that resulted in increased coverage of the OM proteome of a model organism, Caulobacter crescentus. The specificity of the OM enrichment step was improved by using detergent solubilization of the protein pellet, low‐density cell culture conditions, and a surface‐layer deficient cell line. Additionally, efficient gel‐assisted digestion, high‐resolution RP/RP‐MS/MS, and rigorous bioinformatic analysis led to the identification of 234 proteins using strict identification criteria (≥two unique peptides per protein; peptide false discovery rate <2%). Eighty‐four of the detected proteins were predicted to localize to the OM or extracellular space. These results represent ∼70% coverage of the predicted OM/extracellular proteome of C. crescentus. This analytical approach, which considers important experimental variables not previously explored in published OM protein studies, can be applied to other OM proteomic endeavors “as is” or with slight modification and should improve the large‐scale study of this especially challenging subproteome.
A proteomics approach to the cell‐surface interactome using the enzyme‐mediated activation of radical sources reaction
Authors: Jiang Songlin , Kotani Norihiro , Ohnishi Tomoko , Miyagawa‐Yamguchi Arisa , Tsuda Masayuki , Yamashita Ryusuke , Ishiura Yoshihito , Honke Koichi
Published: November 2011

We previously reported a simple method to analyze the interaction of cell‐surface molecules in living cells. This method termed enzyme‐mediated activation of radical sources (EMARS) is featured by radical formation of the labeling reagent by horseradish peroxidase (HRP). Herein, we propose an approach to the cell‐surface molecular interactome by using combination of this EMARS reaction and MS‐based proteomics techniques. In the current study, we employed a novel labeling reagent, fluorescein‐conjugated arylazide. The fluorescein‐tagged proteins resulting from the EMARS reaction were directly detected in the electrophoresis gels with a fluorescence image analyzer. These products were also purified and concentrated by immunoaffinity chromatography with anti‐fluorescein antibody‐immobilized resins. The purified fluorescein‐tagged proteins were subsequently subjected to an MS‐based proteomics analysis. Analysis using HRP‐conjugated cholera toxin subunit B, which recognizes a lipid raft marker, ganglioside GM1, revealed 30 membrane and secreted proteins that were candidates for the cell‐surface molecules coclustering with GM1. The proposed approach will provide a clue to study functional molecular interactions in a variety of biological events on the cell surface.
Mechanism of N10‐formyltetrahydrofolate synthetase derived from complexes with intermediates and inhibitors
Authors: Celeste Lesa R. , Chai Geqing , Bielak Magdalena , Minor Wladek , Lovelace Leslie L. , Lebioda Lukasz
Published: November 2011

N10‐formyltetrahydrofolate synthetase (FTHFS) is a folate enzyme that catalyzes the formylation of tetrahydrofolate (THF) in an ATP dependent manner. Structures of FTHFS from the thermophilic homoacetogen, Moorella thermoacetica, complexed with (1) a catalytic intermediate—formylphosphate (XPO) and product—ADP; (2) with an inhibitory substrate analog–folate; (3) with XPO and an inhibitory THF analog, ZD9331, were used to analyze the enzyme mechanism. Nucleophilic attack of the formate ion on the gamma phosphate of ATP leads to the formation of XPO and the first product ADP. A channel that leads to the putative formate binding pocket allows for the binding of ATP and formate in random order. Formate binding is due to interactions with the gamma‐phosphate moiety of ATP and additionally to two hydrogen bonds from the backbone nitrogen of Ala276 and the side chain of Arg97. Upon ADP dissociation, XPO reorients and moves to the position previously occupied by the beta‐phosphate of ATP. Conformational changes that occur due to the XPO presence apparently allow for the recruitment of the third substrate, THF, with its pterin moiety positioned between Phe384 and Trp412. This position overlaps with that of the bound nucleoside, which is consistent with a catalytic mechanism hypothesis that FTHFS works via a sequential ping‐pong mechanism. More specifically, a random bi uni uni bi ping‐pong ter ter mechanism is proposed. Additionally, the native structure originally reported at a 2.5 Å resolution was redetermined at a 2.2 Å resolution.
Phytochemical, Antioxidant and Anti‐α‐glucosidase Activity Evaluations of Bergenia cordifolia
Authors: Roselli Mariagrazia , Lentini Giovanni , Habtemariam Solomon
Published: November 2011

The antioxidant, anti‐α‐glucosidase and anticholinesterase activity of the leaves and rhizomatous extract of Bergenia cordifolia were investigated. The rhizomes extract that showed a higher degree of 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging and anti‐α‐glucosidase activity than reference compounds (rutin and acarbose respectively) were subjected to phytochemical analysis. The study revealed that previously unknown minor constituents from the plant, (+)‐catechin 3‐O‐gallate, (+)‐catechin 3,5‐di‐O‐gallate and 1,2,4,6‐tetra‐O‐galloyl‐β‐ d‐glucopyranoside, were the radical scavenging and anti‐α‐glucosidase principles. These compounds as well as the crude extracts were weak acetylcholienesterase inhibitors, suggesting a higher degree of selectivity against α‐glucosidase enzyme. In comparison with the minor constituents, the previously known major constituents of the plant, bergenin and arbutin, were poor radical scavengers and enzyme inhibitors. Copyright © 2011 John Wiley & Sons, Ltd.
Screening for Anti‐inflammatory and Bronchorelaxant Activities of 12 Commonly Used Chinese Herbal Medicines
Authors: Yue Grace G. L. , Chan Ben C. L. , Kwok Hin‐Fai , To Ming‐Ho , Hon Kam‐Lun , Fung Kwok‐Pui , Lau Clara B. S. , Leung Ping‐Chung
Published: November 2011

The use of health supplements derived from medicinal herbs as self‐medication for the relief of respiratory tract pathology symptoms is increasing in Chinese communities as air pollution is worsening. Twelve herbs from two formulae of our previous studies were evaluated for their anti‐inflammatory, immunomodulatory and bronchorelaxant activities in this study. Among the extracts tested, those of Herba Schizonepetae and Radix Glycyrrhizae showed significant inhibitory effects on LPS‐induced nitric oxide production (p < 0.05) in mouse macrophage RAW264.7 cells, suggesting their anti‐inflammatory activities. Radix Scutellariae and Radix Glycyrrhizae extracts showed significant inhibitory effects on phytohaemagglutinin‐induced proliferation in human peripheral blood mononuclear cells (p < 0.05). These extracts also showed inhibition of TNF‐α, IFN‐γ and IL‐10 production. For the bronchorelaxant assay, Rhizoma Cynanchi Stauntonii and Radix Glycyrrhizae extracts showed potent attenuation of the acetylcholine‐ and carbachol‐induced contractions in rat trachea (p < 0.05), implying their relaxant activities.

In conclusion, Herba Schizonepetae, Radix Glycyrrhizae, Radix Scutellariae and Rhizoma Cynanchi Stauntonii extracts were demonstrated to exert anti‐inflammatory, immunomodulatory and bronchorelaxant activities, which may help to ameliorate the symptoms of respiratory tract pathologies. The findings have thus provided some scientific evidence on the efficacy and mechanisms of action of these herbs, which are useful for the further development of clinical applications. Copyright © 2011 John Wiley & Sons, Ltd.
A novel support vector classifier for longitudinal high‐dimensional data and its application to neuroimaging data
Authors: Chen Shuo , DuBois Bowman F.
Published: November 2011

Recent technological advances have made it possible for many studies to collect high dimensional data (HDD) longitudinally, for example, images collected during different scanning sessions. Such studies may yield temporal changes of selected features that, when incorporated with machine learning methods, are able to predict disease status or responses to a therapeutic treatment. Support vector machine (SVM) techniques are robust and effective tools well suited for the classification and prediction of HDD. However, current SVM methods for HDD analysis typically consider cross‐sectional data collected during one time period or session (e.g., baseline). We propose a novel support vector classifier (SVC) for longitudinal HDD that allows simultaneous estimation of the SVM separating hyperplane parameters and temporal trend parameters, which determine the optimal means to combine the longitudinal data for classification and prediction. Our approach is based on an augmented reproducing kernel function and uses quadratic programming for optimization. We demonstrate the use and potential advantages of our proposed methodology using a simulation study and a data example from the Alzheimer's disease Neuroimaging Initiative. The results indicate that our proposed method leverages the additional longitudinal information to achieve higher accuracy than methods using only cross‐sectional data and methods that combine longitudinal data by naively expanding the feature space. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 604–611, 2011
Model‐based clustering of regression time series data via APECM—an AECM algorithm sung to an even faster beat
Authors: Chen Wei‐Chen , Maitra Ranjan
Published: November 2011

We propose a model‐based approach for clustering time series regression data in an unsupervised machine learning framework to identify groups under the assumption that each mixture component follows a Gaussian autoregressive regression model of order p. Given the number of groups, the traditional maximum likelihood approach of estimating the parameters using the expectation‐maximization (EM) algorithm can be employed, although it is computationally demanding. The somewhat fast “tune” to the EM “folk song” provided by the Alternating Expectation Conditional Maximization (AECM) algorithm can alleviate the problem to some extent. In this article, we develop an alternative partial expectation conditional maximization algorithm (APECM) that uses an additional data augmentation storage step to efficiently implement AECM for finite mixture models. Results on our simulation experiments show improved performance in both fewer numbers of iterations and computation time. The methodology is applied to the problem of clustering mutual funds data on the basis of their average annual per cent returns and in the presence of economic indicators. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 567–578, 2011
High‐Voltage Nano‐oxidation in Deionized Water and Atmospheric Environments by Atomic Force Microscopy
Authors: Huang Jen‐Ching , Chen Chung‐Ming
Published: November 2011

This study used atomic force microscopy (AFM), metallic probes with a nanoscale tip, and high‐voltage generators to investigate the feasibility of high‐voltage nano‐oxidation processing in deionized water (DI water) and atmospheric environments. Researchers used a combination of wirecutting and electrochemical etching to transform a 20‐μm‐thick stainless steel sheet into a conductive metallic AFM probe with a tip radius of 60 nm, capable of withstanding high voltages. The combination of AFM, high‐voltage generators, and nanoscale metallic probes enabled nano‐oxidation processing at 200 V in DI water environments, producing oxides up to 66.6 nm in height and 467.03 nm in width. Oxides produced through highvoltage nano‐oxidation in atmospheric environments were 117.29 nm in height and 551.28 nm in width, considerably exceeding the dimensions of those produced in DI water. An increase in the applied bias voltage led to an apparent logarithmic increase in the height of the oxide dots in the range of 200‐400 V. The performance of the proposed high‐voltage nano‐oxidation technique was relatively high with seamless integration between the AFM machine and the metallic probe fabricated in this study. SCANNING 34: 230‐236, 2012 © 2011 Wiley Periodicals, Inc.
Performance analysis of secure beaconing messages for GeoNetworking
Authors: Lee Jong‐Hyouk , Ernst Thierry , Ma Xiaomin
Published: November 2011

GeoNetworking is a protocol specially designed to provide geographical addressing and forwarding for Cooperative Intelligent Transport Systems (ITS). Unlike advanced messages defined in GeoNetworking, beaconing messages are fundamental to periodically advertise essential information, e.g., a vehicle ITS station's geographical position and speed, to neighbor ITS stations. The beaconing messages should be delivered in a secure manner. Otherwise, geographical addressing and forwarding of GeoNetworking cannot be supported as unauthorized actions from attackers break down cooperative communication between ITS stations. However, security mechanisms for beaconing messages come with overhead that affect the overall performance. This being so, in this paper, we analyze the overhead of secure beaconing messages in terms of packet delivery ratio, delay, and normalized throughput. From the conducted numerical analysis, we demonstrate that 1) three parameters such as the number of ITS stations in a given radio range, the backoff window size, and the message size mainly affect the performance; 2) the delay of secure beaconing message is still acceptable with proper channel bit rates; and 3) the normalized throughput of secure beaconing message is better than that of the basic beaconing message. Copyright © 2011 John Wiley & Sons, Ltd.