bluuebunny/crossref_metadata_2025 huggingface dataset:
Simplified hand model including the user's forearm for the study of internal GSM/DCS mobile phone antenna
Authors: Wu Chih‐Hsien , Wong Kin‐Lu , Lin Chun‐I , Su Chih‐Ming , Yeh Shih‐Huang , Tang Chia‐Lun
Published: August 2006

A simplified hand model for the study of internal mobile phone antenna for analyzing its impedance and radiation characteristics with the presence of the user's hand is proposed. The antenna in this study is a compact internal antenna having two separate resonant strips capable of generating two wide bandwidths for GSM and DCS operations. For the simplified hand model, it is a one‐layer hand model including the user's forearm with a relative permittivity of 35 and a conductivity of 0.5 S/m. With this simplified hand model, efficient and reliable simulation study of the mobile phone antenna with the user's hand can be obtained. Detailed effects of the user's hand on the impedance and radiation characteristics of the internal mobile phone antenna are analyzed in this study. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2202–2205, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21935
Novel trapezoidal planar dual‐mode bandpass filter using one single patch resonator
Authors: Xiao Jian‐kang , Li Ying
Published: August 2006

Microstrip bandpass filters are widely used in a variety of microwave systems, particularly in transmitter and receiver sections etc. to select a desired band of frequencies. However, common bandpass filters have deficiencies such as several resonators coupling, coupling gaps, only one attenuation pole in frequency responses, and so on. This paper proposes a triangular dual‐mode bandpass filter and two types of trapezoidal dual‐mode bandpass filters using one single patch resonators with corner cuts or crossed slots. It shows degenerate dual‐mode with corner cuts and unequaled crossed slots can improve the performances of filter greatly. The proposed filters have outstanding virtues such as novel and simple structures as they have one single patch without coupling gaps, small volume, easy integration and miniaturization, and so on. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2142–2145, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21939
Experimental study of the self‐imaging phenomenon with weak‐guiding condition
Authors: Hong Jong‐Kyun , Lee Sang‐Sun
Published: August 2006

This paper investigates a self‐imaging phenomenon in a multimode interference (MMI) coupler. In the experiment, different self‐images which are undefined in MMI theory are observed. This undefined self‐image is named the “pseudo‐self‐image ” (PSI) as a matter of convenience. The characteristics of both the single self‐image (0‐dB self‐image: 0‐dB SI), which is defined in MMI theory, and the PSI are compared and analyzed through simulation and experimentation to estimate the applicability of the PSI. Results show that the PSI has an imaging period the same as the 0‐dB SI, and the excess loss and the extinction ratio of the PSI improve more than those of the 0‐dB SI as the imaging period increases. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2354–2357, 2006;Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.21942
Dual‐band CRLH branch‐line coupler in MIM technology
Authors: Nguyen Hoang V. , Caloz Christophe
Published: August 2006

A dual‐band (DB) composite right/left‐handed (CRLH) branch‐line coupler implemented in metal–insulator–metal technology is presented. A simple and accurate circuit‐model design procedure for DB CRLH transmission lines is described and applied to the coupler. A prototype operating at 4.2 and 5.2 GHz is demonstrated in excellent agreement with both circuit and full‐wave simulations. © 2006 Wiley Periodicals,Inc. Microwave Opt Technol Lett 48:2331–2333, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21948
A 2.4, 5.2, and 5.7 GHz CMFB Gilbert downconverter with low‐voltage cascode current mirror input stage
Authors: Tseng Sheng‐Che , Meng Chinchun , Huang Guo‐Wei
Published: August 2006

A triple‐band (2.4, 5.2, and 5.7 GHz) CMFB downconversion micromixer with a low‐voltage cascode current mirror RF input stage has been demonstrated by the 0.18‐μm CMOS technology in this letter. Micromixer has a single‐ended RF input stage, the CMFB topology is adopted to improve the conversion gain, and a differential‐to‐single output buffer is used to convert the differential output of the mixer into a single‐ended output. The fully integrated downconversion micromixer has the conversion gain of 12 dB, LO‐to‐IF isolation of 43 dB, LO‐to‐RF isolation of 48 dB, and RF‐to‐IF isolation of 18 dB at 2.4 GHz. The mixer has the conversion gain of 7.5 dB, LO‐to‐IF isolation of 54 dB, LO‐to‐RF isolation of 49.5 dB, and RF‐to‐IF isolation of 25 dB at 5.7 GHz. The total quiescent current consumption of the circuit is 7.6 mA. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2345–2349, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21950
NMR assignments of a di‐pentacyclo‐undecane cyclic ether
Authors: Kruger Hendrik G. , Ramdhani Reshika
Published: August 2006

The X‐ray structure of a di‐pentacyclo‐undecane cyclic ether was recently reported. As part of a programme to use NMR spectroscopy for the structure elucidation of cage compounds, the complete NMR assignments of the cyclic ether was attempted. Major overlap of proton and carbon signals of the two cages is observed. It was required to elucidate the fragment analogues that represent similar structural features of the cyclic ether in order to get an approximate but reasonable insight into the complex overlapping signals. Normal 2D NMR techniques were utilized to assign the various NMR signals. Copyright © 2006 John Wiley & Sons, Ltd.
Proteins of the accessory sex glands associated with the oocyte‐penetrating capacity of cauda epididymal sperm from holstein bulls of documented fertility
Authors: Moura Arlindo A. , Chapman David A. , Killian Gary J.
Published: August 2006

We previously reported that accessory sex gland fluid (AGF) from high fertility (HF) bulls influenced the oocyte‐penetrating capacity of cauda epididymal sperm from low fertility (LF) bulls, based on in vitro fertilization (IVF) assays. The present study determined if AGF proteins were associated with these effects. Nineteen IVF assays with 12 bulls were grouped as follows. Group I (n = 8): assays where sperm from LF bulls exposed to AGF from HF bulls had greater oocyte penetration than exposed to homologous AGF. Group II (n = 7): sperm from LF bulls to AGF from HF bulls versus homologous AGF showed no significant differences. Group III (n = 4): sperm from LF bulls treated with homologous AGF had greater fertility than sperm treated with AGF from HF bulls. Sire fertility was based on nonreturn rates (NNR) and AGF collected by artificial vagina from bulls with cannulated vasa deferentia. Two‐dimensional SDS–PAGE maps of AGF were analyzed by PDQuest and proteins identified by tandem mass spectrometry and Western blots. Differences in spot intensity between AGF of HF and LF bulls were compared across groups of IVF assays (P < 0.05). The expression of BSP A1/A2 and A3, BSP 30 kDa, clusterin, albumin, phospholipase A2 (PLA2), and osteopontin was greater in the AGF of HF bulls in Group I as compared to Groups II and III. Conversely, there was less nucleobindin in the AGF of HF bulls in Group I than in Groups II and III. This is the first report of nucleobindin (58 kDa/pI 5.6) in male reproductive fluids, using both immunoblots and mass spectrometry. Thus, the effect of AGF from HF bulls on epididymal sperm is likely the result of specific proteins expressed in the AGF. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Pronuclear stage porcine embryos do not possess a strict asymmetric distribution of lysine 9 dimethylation of histone H3 based solely on parental origin
Authors: Sega Martiana F. , Lee Kiho , Machaty Zoltan , Cabot Ryan
Published: August 2006

Epigenetic modification of core histone proteins plays an important role in gene transcription and chromatin structure. It is known that the methylation status of the lysine 9 residue of histone H3 (H3K9) is closely linked with repression of transcription and heterochromatin formation. It has been reported that a strict asymmetric distribution of the dimethylated form of H3K9 exists between the two parental genomes in murine embryos. The aim of this study was to characterize the H3K9 dimethylation pattern in cleavage stage porcine embryos. Indirect immunocytochemical analysis showed that this modification is present throughout the nuclei of pronuclear, 2‐cell, 4‐cell and blastocyst stage porcine embryos. However, at the pronuclear stage the pronuclei within in vitro‐fertilized porcine embryos possessed an asymmetric distribution of the dimethylated form of H3K9; this distribution was not based solely on the parent‐of‐origin. These results show that dimethylation of H3K9 is differentially regulated in pronuclear stage porcine embryos. Mol. Reprod. Dev. 74: 2–7, 2007. © 2006 Wiley‐Liss, Inc.
Maternal low protein diet restricted to the preimplantation period induces a gender‐specific change on hepatic gene expression in rat fetuses
Authors: Kwong Wing Yee , Miller Daniel J. , Wilkins Adrian P. , Dear Mark S. , Wright J. Neville , Osmond Clive , Zhang Junlong , Fleming Tom P.
Published: August 2006

It has been shown previously that maternal low protein diet (LPD) throughout rat gestation altered hepatic gene expression and enzyme activities in offspring. Here, we investigate the effect of maternal LPD (9% casein vs. 18% control) exclusively during the preimplantation period (switched diet group) or provided throughout gestation on hepatic gene expression in day 20 fetuses. Using quantitative competitive PCR, we found that switched diet induced a two‐fold increase (P = 0.008) in hepatic gene expression of phosphoenolpyruvate carboxykinase (PEPCK, a rate limiting enzyme for gluconeogenesis) in male fetuses and a 17% increase (P = 0.005) in 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1, acts primarily as a reductase to produce active glucocorticoid) in female liver compared with control fetuses. Maternal LPD administered throughout gestation increased 11β‐HSD1 expression in male fetal liver by 27% (P = 0.042) compared with controls. However, maternal LPD fed for either period did not affect fetal hepatic insulin receptor (IR), glucocorticoid receptor (GR), glycogen synthase (GS) nor placental glucose transporter 1 (Glut1) and 3 (Glut3) transcript levels. The alteration in fetal hepatic gene expression could not be attributed specifically to known regulators including insulin or glucose concentrations in fetal blood nor alteration in cAMP in fetal liver, although a combination of these regulatory factors may be responsible. Fetal hepatic glycogen level was unaffected by maternal diet. The present findings show that the long term potential of the preimplantation embryo is sensitive to maternal LPD such that basal levels of hepatic gene expression in day 20 fetuses are altered in a gender‐specific manner. Mol. Reprod. Dev. 74: 48–56, 2007. © 2006 Wiley‐Liss, Inc.
Off‐resonance saturation as a means of generating contrast with superparamagnetic nanoparticles
Authors: Zurkiya Omar , Hu Xiaoping
Published: August 2006

This work demonstrates an alternative approach, termed off‐resonance saturation (ORS), for generating contrast that is sensitive to superparamagnetic particles. This method leads to a calculated contrast that increases with superparamagnetic nanoparticle concentration. Experimental data demonstrate that in the presence of superparamagnetic particles, an off‐resonance effect exists that is distinct from the magnetization transfer (MT) effect and is highly dependent on diffusion. Data show that the dependence on water diffusion becomes most significant at rates of 0.5 × 10–9 m2/s and slower. We investigated the dependence of the off‐resonance effect on off‐resonance frequency and particle concentration. The data suggest a useful frequency offset range of 500 Hz < |Δω| < 1500 Hz at 3T. This approach may be especially useful in organs and diseases in which diffusion may be altered by pathologies. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Formulation of a three‐dimensional rate‐dependent constitutive model for chalk and porous rocks
Authors: Hickman R. J. , Gutierrez M. S.
Published: August 2006

Rate‐dependent behaviour of chalk and other porous rocks has undergone widespread study in geomechanics due to its implications on the performance of engineering structures. We present a rate‐dependent constitutive model for chalk and other porous rocks with several new features. The model formulation is based on a viscoplastic rate‐lines approach in which the axial strain rate depends on the proximity of the stress point to an elliptical reference surface. A non‐associated viscoplastic potential surface and an axial scaling algorithm are used to determine the viscoplastic strain components. The model predicts that axial yields stress varies as a power function of applied axial strain rate, as shown by published laboratory data. Comparisons with published experimental data indicate that the model is capable of reproducing observed rate‐dependent behaviour of chalk under a variety of loading conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Innervation of the rectovaginal wall in patients with rectocele compared to healthy controls
Authors: Altman Daniel , Zhang Anjou , Falconer Christian
Published: August 2006

Aims

To evaluate if pelvic floor innervation differed in patients with rectocele compared to control subjects and to assess if nerve fiber density of the rectovaginal wall correlated to the clinical presentation of rectocele.

Methods

Biopsies from 24 female patients with posterior vaginal wall prolapse stage II (ICS‐classification) and rectocele verified at defecography were compared to specimens from age and parity‐matched control subjects without posterior vaginal wall prolapse. Nerve fiber density was measured using protein gene product (PGP‐9.5) antibodies at immunohistochemistry. Anorectal symptoms were recorded using bowel and anorectal function questionnaires.

Results

The two groups were comparable in age and parity. Mean nerve fiber immunofluorescence intensity was 150.3 ± 12.5 SD in the patient group compared to 139.3 ± 8.5 SD in the control group (P < 0.01). Symptoms of anorectal dysfunction were more common in the patient group compared to control subjects (P < 0.01) but there was no difference in anal continence. At logistic regression analysis, nerve fiber immunofluorescence intensity showed no significant correlation to age, menopausal age, parity, body mass index (BMI), prolapse quantification, or any specific self‐reported anorectal symptom. Increased nerve fiber immunofluorescence intensity was correlated to increased perineal descent (OR 1.3, 95% CI 1.1–2.1) although not to the size of the rectocele (OR 0.5, 95% CI 0.9–1.2).

Conclusions

Our results show that rectocele may be associated with increased rectovaginal innervation, suggestive of reinnervation of the rectovaginal wall. Nerve fiber density correlated poorly with findings at clinical and radiological examination. Neurochemical characterization of the rectovaginal wall may provide further understanding of the pathogenesis of rectocele. Neurourol. Urodynam. 25:776–781, 2006. © 2006 Wiley‐Liss, Inc.
ZnO layers deposited by the ion layer gas reaction on Cu(In,Ga)(S,Se)2thin film solar cell absorbers—impact of ‘damp‐heat’ conditions on the layer properties
Authors: Bär M. , Reichardt J. , Sieber I. , Grimm A. , Kötschau I. , Lauermann I. , Sokoll S. , Niesen T. P. , Lux‐Steiner M. C. , Fischer Ch.‐H.
Published: August 2006

Cu(In,Ga)(S,Se)2(‘CIGSSe’) based solar cells with a ZnO window extension layer (WEL) deposited by the ion layer gas reaction (ILGAR) reach competitive efficiencies compared to corresponding references with CdS buffer and lead to a simplified device structure. The WEL replaces not only the CdS buffer, but also the undoped part of the usually appliedrf‐sputtered ZnO window bi‐layer. The long‐term stability of CIGSSe‐based solar modules is currently under investigation. In order to pass the respective stability tests, which include exposure to ‘damp‐heat’ (DH) conditions (85% relative humidity at 85(C) to accelerate possible aging effects, a good intrinsic material stability is required. In Reference1it was revealed, that ILGAR‐ZnO contains a certain amount of meta‐stable hydroxide, which can be directly tuned by the ILGAR process parameters (number of process cycles and process temperature). In order to determine the ILGAR process parameters, which result in intrinsically stable WELs, ILGAR‐ZnO/CIGSSe test structures were investigated by means of scanning electron microscopy (SEM) and x‐ray photoelectron spectroscopy (XPS) before and after a DH‐test. It was found that, induced by the DH‐conditions, a continuous dehydration of the WELs together with a disintegration of the ILGAR‐ZnO layers takes place. This supports an earlier suggested mechanism of a DH‐induced degradation by a release of water at the most critical location in a solar cell, at the heterointerface between window and absorber. By a systematic variation of the ILGAR process parameters it was possible to reduce the hydroxide content in the ILGAR‐ZnO layers resulting in intrinsically more stable samples. Copyright © 2006 John Wiley & Sons, Ltd.
Analyzing historical cost trends in California's market for customer‐sited photovoltaics
Authors: Wiser Ryan , Bolinger Mark , Cappers Peter , Margolis Robert
Published: August 2006

This paper reports highlights from a detailed statistical analysis of the cost of customer‐sited, grid‐connected photovoltaic installations in the largest solar market in the United States: California. It is based on an analysis of 18 942 PV systems, totaling 254 MWAC, either funded or approved for funding under two separate rebate programs overseen by the California Energy Commission and the California Public Utilities Commission. We find that: (1) solar costs have declined substantially over time; (2) policy incentives have impacted pre‐rebate installed costs, and some cost inflation is apparent; (3) economies of scale have driven down costs for larger systems; (4) systems installed in new home developments and in affordable housing projects have experienced much lower costs than the general retrofit market; and (5) installer experience and type have affected costs, but the effects differ by program. Results hold important implications for solar suppliers and customers, and for policymakers designing incentive programs. Copyright © 2006 John Wiley & Sons, Ltd.
Comparative proteomic analysis of cisplatin sensitive IGROV1 ovarian carcinoma cell line and its resistant counterpart IGROV1‐R10
Authors: Le Moguen Karen , Lincet Hubert , Deslandes Edwige , Hubert‐Roux Marie , Lange Catherine , Poulain Laurent , Gauduchon Pascal , Baudin Bruno
Published: August 2006

Ovarian cancer is one of the leading causes of mortality due to gynaecological cancer. Despite a good response to surgery and initial chemotherapy essentially based on cisplatin (cis‐diamino‐dichloro‐platinum(II) (CDDP)) compounds, late tumour detection and frequent recurrences with chemoresistance acquisition are responsible for poor prognosis. Several mechanisms have been implicated in CDDP resistance but they are not sufficient to exhaustively explain this resistance emergence. We applied a proteomic approach based on 2‐DE coupled with MS to identify proteins associated with the chemoresistance process. We first established a proteomic pattern of the CDDP sensitive ovarian cell line IGROV1 using MALDI‐TOF‐MS and PMF. We then compared this 2‐D pattern with that of the CDDP‐resistant counterpart IGROV1‐R10. Among the 40 proteins identified, cytokeratins 8 and 18 and aldehyde dehydrogenase 1 were overexpressed in IGROV1‐R10, whereas annexin IV was down‐regulated. These observations have been confirmed by Western blotting. The characterization of such variations could lead to the development of new protein markers or to the establishment of new therapeutic strategies. Moreover, the identification of proteins involved in CDDP resistance in ovarian tumours would be useful in completing our understanding on this complex mechanism.
Effect of large deformation and material nonlinearity on the JKR (Johnson–Kendall–Roberts) test of soft elastic materials
Authors: Lin Yu‐Yun , Chen Hsin‐Yang
Published: August 2006

We study in detail the effect of large deformation and material nonlinearity on the JKR (Johnson–Kendall–Roberts) theory of adhesive contact for two systems. The first is a Neo‐Hookean hemisphere in adhesive contact with a smooth rigid substrate. The second is a smooth rigid spherical indenter in adhesive contact with a Neo‐Hookean half space. We show that our results are special cases of a general theory that models large deformation adhesive contact of spherical lenses. This theory shows that the solution of any large deformation JKR (LDJKR) problem can be obtained from the solution of a corresponding large deformation Hertz (LDH) problem. Using this theory, we extend the small strain JKR theory to the large deformation regime, the only restriction being that the materials are nonlinear elastic or hyperelastic. The adhesive contact problem for the two systems is solved using two methods. In method one, the LDJKR theory is obtained using finite element simulation results for a corresponding LDH problem; in method two, we solve the adhesive contact problems directly using a cohesive zone model to quantify adhesive interaction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2912–2922, 2006
Solid‐state NMR characterizations on phase structures and molecular dynamics of poly(ethylene‐co‐vinyl acetate)
Authors: Wang Liying , Fang Pengfei , Ye Chaohui , Feng Jiwen
Published: August 2006

Solid‐state nuclear magnetic resonance spectroscopy and relaxation measurements, together with DSC, have been used to elucidate the structures and molecular dynamics in poly(ethylene‐co‐vinyl acetate) (EVA). It has been found that besides immobile orthorhombic and monoclinic crystalline phases, the third mobile crystalline phase (possibly the phase) of a considerable amount (36% of total crystalline phases) appears in the EVA samples, which forms during room‐temperature aging as a result of the secondary crystallization and melts at temperature somewhat higher than room temperature. Such a mobile crystalline phase has not only the well‐defined chemical shift of its own, but also has different molecular mobility from the orthorhombic phase. The mobile crystalline phase is characterized by the rapid relaxation of the longitudinal magnetization, which is caused by conventional spin‐lattice relaxation, while the slow relaxation of the longitudinal magnetization occurring in the orthorhombic phase is originated from the chain diffusion. In addition, the amorphous phase also contains two components: an interfacial amorphous phase and a melt‐like amorphous phase. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2864–2879, 2006
Isotopically engineered semiconductors: from the bulk to nanostructures
Authors: Ager Joel W. , Haller Eugene E.
Published: August 2006

Research performed with semiconductors with controlled isotopic composition is evolving from the measurement of fundamental properties in the bulk to those measured in superlattices and nanostructures. This is driven in part by interests associated with the fields of “spintronics” and quantum computing. In this topical review, which is dedicated to Prof. Abstreiter, we introduce the subject by reviewing classic and recent measurements of phonon frequencies, thermal conductivity, bandgap renormalizations, and spin coherence lifetimes in isotopically controlled bulk group IV semiconductors. Next, we review phonon properties measured in isotope heterostructures, including pioneering work made possible by superlattices grown by the group of Prof. Abstreiter. We close the review with an outlook on the exciting future possibilities offered through isotope control in 1, 2, and 3 dimensions that will be possible due to advances in nanoscience. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthetic diamond devices for radio‐oncology applications
Authors: Descamps C. , Tromson D. , Mer C. , Nesládek M. , Bergonzo P. , Benabdesselam M.
Published: August 2006

Diamond exhibits a range of outstanding properties that make it a material of interest for radiation detection and particularly in the field of dosimetry applications. In fact, its crystallographic structure makes it chemically inert and radiation hard. Moreover, its atomic number (carbon Z = 6) close to the equivalent effective atomic number of human soft tissues (Z = 7.4) and of water (reference material in radiotherapy) enables a direct evaluation of the deposited dose without requiring corrections for material nature or energy. Finally, as a bio‐compatible material, it can be sterilised, and it is non‐toxic thus giving strong advantages for medical uses. Natural diamonds are expensive, rare and their use implies a severe gem selection to fabricate reproducible and reliable devices. The emergence of synthetic samples from the chemical vapour deposition (CVD) technique offers new possibilities in the fabrication of ionisation chamber for the particular field of radiotherapy. Previous studies have shown that defect levels present in material clearly influence the device response under irradiation. Therefore, in order to optimise dosimetric characteristics needed in radiotherapy applications, various low and precisely nitrogen concentrations were incorporated in the material during growth. Influence of these incorporations on ionisation chamber response under medical cobalt irradiator is presented in this paper. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reducing the Impact of Missing Values in Factorial Experiments Arranged in Blocks
Authors: Godolphin J. D.
Published: August 2006

The loss of one or more observations during a designed experiment is a hazard well known to statistical practitioners, including practising engineers involved in product design and development. When observations are missing the eventual experimental design is necessarily altered from the design that was selected originally. This can introduce unwelcome difficulties, even though the available software may allow for missing values in the analysis of the surviving data. In particular, if missing values are incurred in a replicated factorial experiment arranged in blocks, the eventual design may be disconnected with respect to some factors under investigation and the experiment may be seriously damaged. It is suggested that the vulnerability of the original design should be examined at the planning stage of the experiment so that suitable action can be taken before any experimentation is done. These points are illustrated by considering an experiment consisting of three replicates of a full 23 factorial arranged in rows and columns and it is shown how to recognize the vulnerability of designs before the experimental process has taken place. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of aranidipine and its active metabolite in human plasma by liquid chromatography/negative electrospray ionization tandem mass spectrometry
Authors: Tian Lei , Jiang Juanjuan , Huang Yiling , Xu Li , Liu Hong , Li Yishi
Published: August 2006

A simple, sensitive and rapid high‐performance liquid chromatography/negative electrospray ionization tandem mass spectrometry method was developed and validated for the assay of aranidipine (AR) and its active metabolite (AR‐M) in human plasma. Following a liquid‐liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase column and analyzed by mass spectrometry in the multiple reaction monitoring mode using the respective [MH]− ions, m/z 387.0 → 164.0 for AR, m/z 389.1 → 208.1 for AR‐M and m/z 359.0 → 121.8 for the internal standard. The assay exhibited a linear dynamic range of 0.02–10 ng · mL−1 for AR and 0.2–100 ng · mL−1 for AR‐M in human plasma. The limits of quantitation were 0.02 ng · mL−1 for AR and 0.2 ng · mL−1 for AR‐M. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.8 min for each sample exhibited its high‐throughout analysis ability. The validated method can be applied to analyze human plasma samples for pharmacokinetic studies. Copyright © 2006 John Wiley & Sons, Ltd.
Cloud point extraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry for the speciation of inorganic selenium in environmental water samples
Authors: Chen Beibei , Hu Bin , He Man
Published: August 2006

A new method based on cloud point extraction (CPE) separation and electrothermal vaporization inductively coupled plasma mass spectrometry (ETV‐ICPMS) detection has been proposed for the speciation of inorganic selenium in environmental waters. When the temperature of the system is higher than the cloud point temperature (CPT) of the selected surfactant Triton X‐114, the complex of Se(IV) with ammonium pyrrolidine dithiocarbamate (APDC) seems to be extracted into the surfactant‐rich phase, whereas the Se(VI) remains in aqueous solutions. Thus, an in situ separation of Se(IV) and Se(VI) could be realized. The concentrated analyte was introduced into the ETV‐ICP mass spectrometer for determination of Se((IV) after dilution with 200 µL methanol. Se(VI) was reduced to Se(IV) prior to determining total selenium, and its assay was based on subtracting Se(IV) from total selenium. The main factors affecting the CPE and the vaporization behavior of the analyte were investigated in detail. Under the optimized experimental conditions, the limit of detection (LOD) for Se(IV) was 8.0 ng/L with an enhancement factor of 39 when 10 mL of sample solution was preconcentrated to 0.2 mL. The relative standard deviation (RSD) was found to be 3.9% (CSe(IV) = 1.0 µg/L, n = 7). The proposed method was applied to the speciation of inorganic selenium in different environmental water samples with the recovery for the spiked samples in the range of 82–102%. Copyright © 2006 John Wiley & Sons, Ltd.
Desorption sonic spray ionization for (high) voltage‐free ambient mass spectrometry
Authors: Haddad Renato , Sparrapan Regina , Eberlin Marcos N.
Published: August 2006

Sonic spray ionization is shown to create a supersonic cloud of charged droplets able to promote efficient desorption and ionization of drugs directly from the surfaces of commercial drug tablets at ambient conditions. Compared with desorption electrospray ionization (DESI), desorption sonic spray ionization (DeSSI) is advantageous since it uses neither heating nor high voltages at the spray capillary. DeSSI therefore provides a more friendly environment in which to perform ambient mass spectrometry (MS). DeSSI‐MS is herein evaluated for the analysis of drug tablets, and found to be, in general, as sensitive as DESI‐MS. The (high) voltage‐free DeSSI method provides, however, cleaner mass spectra with less abundant solvent cluster ions and with enough abundant analyte signal for tandem mass spectrometry (MS/MS). These features may therefore facilitate the DeSSI‐MS detection of low molar mass components or impurities, or both. The higher‐velocity supersonic DeSSI spray also facilitates matrix penetration thus providing more homogenous sampling and longer lasting ion signals. Copyright © 2006 John Wiley & Sons, Ltd.
Predictive control of parabolic PDEs with state and control constraints
Authors: Dubljevic Stevan , El‐Farra Nael H. , Mhaskar Prashant , Christofides Panagiotis D.
Published: August 2006

This work focuses on predictive control of linear parabolic partial differential equations (PDEs) with state and control constraints. Initially, the PDE is written as an infinite‐dimensional system in an appropriate Hilbert space. Next, modal decomposition techniques are used to derive a finite‐dimensional system that captures the dominant dynamics of the infinite‐dimensional system, and express the infinite‐dimensional state constraints in terms of the finite‐dimensional system state constraints. A number of model predictive control (MPC) formulations, designed on the basis of different finite‐dimensional approximations, are then presented and compared. The closed‐loop stability properties of the infinite‐dimensional system under the low order MPC controller designs are analysed, and sufficient conditions that guarantee stabilization and state constraint satisfaction for the infinite‐dimensional system under the reduced order MPC formulations are derived. Other formulations are also presented which differ in the way the evolution of the fast eigenmodes is accounted for in the performance objective and state constraints. The impact of these differences on the ability of the predictive controller to enforce closed‐loop stability and state constraints satisfaction in the infinite‐dimensional system is analysed. Finally, the MPC formulations are applied through simulations to the problem of stabilizing the spatially‐uniform unstable steady‐state of a linear parabolic PDE subject to state and control constraints. Copyright © 2006 John Wiley & Sons, Ltd.
Systematization of approaches to adaptive boundary stabilization of PDEs
Authors: Krstic Miroslav
Published: August 2006

While adaptive control of finite dimensional systems is an advanced field that has produced adaptive control methods for a very general class of LTI systems, adaptive control techniques have been developed for only a few of the classes of PDEs for which non‐adaptive controllers exist. We present a catalog of approaches for the design of adaptive controllers for PDEs controlled from a boundary and containing unknown destabilizing parameters affecting the interior of the domain. We differentiate between two major classes of schemes: Lyapunov schemes and certainty equivalence schemes. Within the certainty equivalence class, two types of identifier designs are pursued: passivity‐based and swapping designs. Each of those designs is applicable to two types of parametrizations: the plant model in its original form (which we refer to as the ‘u‐model’) and a transformed model to which a backstepping transformation has been applied (which we refer to as the ‘w‐model’). Hence, a large number of control algorithms result from combining different design tools—Lyapunov schemes, w‐passive schemes, u‐swapping schemes, etc.

Our method builds upon the explicitly parametrized control formulae that we introduced in our earlier work on non‐adaptive backstepping control for PDEs. These formulae allow us to develop tunable controllers that avoid solving Riccati or Bezout equations at each time step.

This paper is primarily a tutorial. Its purpose is to provide structure that helps the future reader of five other papers currently under review which contain the detailed proofs for the designs presented here. Additionally, the paper can serve as an entry point for a non‐expert reader interested in an introduction to adaptive boundary control of PDEs. For this reason, our presentation proceeds through a series of examples, which are generalized in the companion papers. Copyright © 2006 John Wiley & Sons, Ltd.
Presumptive adaptation and the effectiveness of knowledge transfer
Authors: Szulanski Gabriel , Jensen Robert J.
Published: August 2006

Adaptation almost invariably accompanies the cross‐border transfer of firm‐specific practices. The existing literature contains two conflicting approaches to adaptation. The first, more traditional approach, following institutional, motivational, and pragmatic efficiency considerations, presumes that a modified practice can be fine tuned, stabilized, and institutionalized without consulting a working example and that practices should thus be adapted as quickly as possible to create fit with the local environment. The second approach argues, instead, for the need to maintain the diagnostic value of the original practice by adapting cautiously and gradually. In this paper, we report an in‐depth field investigation of the relationship between presumptive adaptation, adaptation that removes the diagnostic value of the original practice, and transfer effectiveness. The setting is the transfer of franchising knowledge across borders. We investigate how adherence to recommended practices affects the rate of network growth in the host country. We find that presumptive adaptation stalls network growth while a conservative approach to adaptation, which basically entails close adherence to the original practice, results in remarkably rapid network growth. We conclude that presumptive adaptation of knowledge assets could be detrimental to performance. Copyright © 2006 John Wiley & Sons, Ltd.
Highly Crystalline WO3 Thin Films with Ordered 3D Mesoporosity and Improved Electrochromic Performance
Authors: Brezesinski Torsten , Fattakhova Rohlfing Dina , Sallard Sébastien , Antonietti Markus , Smarsly Bernd M.
Published: August 2006

WO3 thin layers with nanometer‐scale periodicity were prepared by evaporation‐induced self‐assembly (EISA) using a novel amphiphilic block‐copolymer template (poly(ethylene‐co‐butylene)‐block‐poly(ethylene oxide)). The evolution of the mesoporous ordered network and the crystallinity of the framework were monitored by 2D‐SAXS, WAXS, SEM, XPS, and porosimetry. By annealing the films, the pore‐wall crystallinity is adjusted between fully amorphous and highly crystalline without mesostructural degradation. Thus, the crystalline‐film framework is composed of phase‐pure monoclinic WO3 nanoparticles (12–14 nm in size). Furthermore, heat treatment transforms the originally spherical mesopores into ellipsoids, resulting in a unidirectionally shrunken, but still well‐defined and fully accessible bcc mesopore architecture. The influence of mesoporosity and crystallinity on electrochemical/electrochromic characteristics was addressed by monitoring electrochemical features and the absorption changes during Li insertion/extraction (repetitive potentiostatic cycling). Both the amorphous and crystalline mesoporous films possess electrochromic response times on the order of only seconds, which are attributable to the facilitated insertion of guest ions due to shortening of the diffusion path lengths. Also, the insertion/extraction reversibility of crystalline WO3 layers with 3D mesoporosity is improved compared to amorphous ones and reaches values close to 100 %.
Fetal urinoma: two new cases and a review of the literature
Authors: Gorincour G. , Rypens F. , Toiviainen‐Salo S. , Grignon A. , Lambert R. , Audibert F. , Garel L. , Fournet J.‐C.
Published: August 2006

Objective

To evaluate the functional prognosis of kidneys affected prenatally by urinomas.

Methods

This was a retrospective review of cases of fetal urinoma reported in the literature, as well as two of our own cases.

Results

Twenty‐three patients with a prenatal diagnosis of urinoma (five bilateral) were included in the analysis. Postnatal ipsilateral renal function was observed in only six of the 28 renal units (i.e. around 20%).

Conclusions

Although the precise causes of urinomas are still unknown, this review shows that in the event of a fetal urinoma, the probability of a non‐functional dysplastic ipsilateral kidney lies at around 80%. In‐utero puncture only appears to be justified in cases where fluid accumulation has mass effects on adjacent major structures. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Management of Kell isoimmunization — evaluation of a Doppler‐guided approach
Authors: Rimon E. , Peltz R. , Gamzu R. , Yagel S. , Feldman B. , Chayen B. , Achiron R. , Lipitz S.
Published: August 2006

Objective

To assess the role of peak systolic velocity in the middle cerebral artery (MCA‐PSV) in the management of pregnancies complicated by Kell isoimmunization.

Methods

Sixteen fetuses were monitored by conventional protocol (Group 1) and eight fetuses by an MCA‐PSV‐guided protocol (Group 2). The conventional protocol included a weekly ultrasound evaluation and measurement of maternal anti‐Kell titers every 4–6 weeks. In Group 2 Doppler assessment of the MCA‐PSV was performed at intervals of 4 to 7 days and MCA‐PSV > 1.5 multiples of the median (MoM) was considered as an indication for fetal blood sampling (FBS).

Results

No parameter emerged as a reliable predictor of isoimmunization severity in Group 1. In Group 2, no FBS was necessary in one case since the MCA‐PSV values obtained during the follow‐up were < 1.29 MoM. In two cases the first FBS was already indicated after 1 week of follow‐up, but five other fetuses were followed for 3–9 weeks before FBS was indicated. All fetuses with MCA‐PSV > 1.5 MoM prior to intrauterine transfusion (IUT) had severe fetal anemia on FBS. In fetuses with severe anemia on the first FBS, the MCA‐PSV values 7 days before the first FBS were < 1.29 MoM (four cases), between 1.29 and 1.5 MoM (two cases) and > 1.55 MoM (one case).

Conclusions

In the management of Kell isoimmunization invasive procedures may be avoided by implementing MCA‐PSV measurements. Delineation of appropriate intervals between reassessments, the reliability of MCA‐PSV following repeated IUTs, and cut‐off values for FBS await further study. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Understanding the key performance issues with MAC protocols for multi‐hop wireless networks
Authors: Iyer Aravind , Rosenberg Catherine
Published: August 2006

Multi‐hop wireless networks arise in the context of ad hoc networks, sensor networks, and mesh networks, and their performance depends critically on the underlying medium access control (MAC) protocol. Inspite of the large body of work devoted to MAC protocols and associated problems, the relative importance of these problems is still not well understood. This is because most of the previous work focuses on designing a protocol to solve a particular problem, or on identifying scenarios where a protocol will not work well. In addition, most of the work is also based on simplistic assumptions about the physical wireless medium, like fixed ranges for communication and interference, or concepts like capture threshold where the desired signal strength is compared with interference from a single node at a time, rather than cumulatively.

Our paper seeks to address these issues. We believe it is extremely critical that (i) we develop an understanding of the relative significance of the problems affecting MAC protocols, and that (ii) we use a realistic model for the physical channel for design and performance evaluation. Towards this end, we evaluate the performance of three currently proposed MAC protocols, IEEE 802.11 [1], RI‐BTMA [2], and DUCHA [3] under a realistic channel model with additive interference. Since these protocols solve or suffer from different sets of problems, our evaluation provides a differential diagnosis of the severity of these problems. Based on our observations, we propose a simple and robust two channel MAC protocol (entitled 2CM) that is based on IEEE 802.11 augmented with a busy‐tone channel. The 2CM protocol (i) mitigates the hidden node problem considerably, (ii) does not waste bandwidth in terms of logical control channels, and (iii) provides a reliable link layer acknowledgment. Through extensive simulations, we show that 2CM offers a consistently high throughput performance while not sacrificing link layer reliability in a variety of scenarios, thereby vindicating our approach. Copyright © 2006 John Wiley & Sons, Ltd.
Investigation of the block ACK scheme in wireless ad hoc networks
Authors: Li Tianji , Ni Qiang , Xiao Yang
Published: August 2006

A Block Transmission and Acknowledgement (BTA) scheme, also called Block ACK, has been proposed in the IEEE 802.11e wireless local area networks (WLAN) specification to improve efficiency of the medium access control layer. The idea of the BTA scheme is to transmit multiple data frames followed by only one acknowledgement frame in a transmission block. In this paper, we present a theoretical model to evaluate the saturation throughput for the BTA scheme under error channel conditions in the ad hoc mode, validated with simulations. We show some advantages of BTA over the legacy MAC, and analyze how to select a proper number of frames for each transmission block. Results show that BTA is particularly effective in very high‐speed wireless networks, and it is important that the number of frames in each block is negotiated before transmissions to provide better efficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Chemical speciation via X‐ray emission spectra
Authors: Ankudinov A. L. , Elam W. T. , Sieber J. R. , Rehr J. J.
Published: August 2006

Since the early days of X‐ray spectrometry, X‐ray emission and fluorescence spectra have been used to investigate chemical speciation, e.g. the dependence on the formal oxidation state. Laboratory wavelength‐dispersive spectrometers have adequate resolution for these measurements. However, almost all studies have employed empirical methods to interpret the spectra. We aim to place such methods on a quantitative basis by means of efficient ab initio calculations of the X‐ray emission line shapes based on a self‐consistent, real‐space Green's function approach, as implemented in the X‐ray spectroscopy code FEFF8.2. Calculations are presented for the phosphorus K‐M2, 3, and the chromium L‐series emission lines for a selection of simple compounds. These lines exhibit changes depending on the oxidation state and on the neighboring atoms in the compounds that can be observed with instruments available in many XRF laboratories. The calculated spectra, as modified by convolution with a model monochromator response function, are compared with measured spectra. Simulated and measured spectra are found to be in reasonable agreement, and show that the approach has the potential to yield quantitative information about the chemical state. Copyright © 2006 John Wiley & Sons, Ltd.
Salicornia ramosissima population dynamics and tolerance of salinity
Authors: Silva Helena , Caldeira Gustavo , Freitas Helena
Published: August 2006

Field and greenhouse studies have been conducted to clarify aspects of population dynamics and NaCl tolerance of Salicornia ramosissima J. Woods. Two populations, Varela and Verdemilho, were monitored in the field during two consecutive life cycles and aspects of their morphology and density were recorded monthly. In the laboratory seedlings were exposed to different salinity for 10 weeks and growth and mortality rate were recorded weekly. The growth of the populations differed significantly, possibly because of the different salinities of the two sampling sites and/or genetic adaptations of the two populations to the environmental conditions. The absence of a significant correlation between sediment salinity and stem elongation suggested, however, that salinity, alone was not responsible for the differences observed and was possibly associated with other factors, because of nutritional, edaphic, and microclimatic conditions. S. ramosissima did not develop well in conditions of elevated or moderate salinity; its growth was optimum at low salinity. Optimum development of S. ramosissima may, nevertheless, depend on the total number of large seeds in a population seed bank, because of their greater success in germination and germinability under stress conditions than small seeds.