bluuebunny/crossref_metadata_2025 huggingface dataset:
A dual‐band receiver front‐end using current‐mode passive mixer with digitally‐controlled oscillator in 90‐NM CMOS
Authors: Chen Jinghong , Li Shaorui , Appel Craig , Hotron Brian , Lawrence
Published: May 2008

This work presents a receiver front‐end that targets mobile video applications, and integrates a dual‐band LNA, a current‐mode passive mixer, a reference Gilbert mixer, and a digitally‐controlled oscillator providing the quadrature LO signal for the mixers. The conversion gain and thermal noise performances of the current‐mode passive mixer are studied. Design tradeoffs among noise, linearity, and conversion gain are performed. Measured performance of the receiver front‐end shows a flicker noise corner of 70 kHz, a noise figure (NF) of 4.4 dB, an input third‐order intermodulation product (IIP3) of −2 dBm, and DCO phase noise of −128 dBc/Hz at 1‐MHz offset. The receiver consumes less than 24 mA of current in a 1.2‐V 90‐nm standard digital CMOS process. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2138–2142, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23587
A novel broadband EBG using cascaded mushroom‐like structure
Authors: Liang L. , Liang C. H. , Chen L. , Chen X.
Published: May 2008

A novel broadband electromagnetic band‐gap (EBG) structure is presented using cascaded mushroom‐like structure with different radius of via. Direct transmission method is used to determine the band‐gap of the EBG structure. The effects of the radius of via and unit number on the mushroom‐like EBG structure are investigated. Two kinds of unit with different via radius are cascaded to enlarge the band‐gap of EBG structure, which achieves almost 70%. The simulation and experimental results show that the band‐gap covers the stop‐band produced by the two uniform configurations with different radius, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2167–2170, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23598
Novel U‐shaped strip‐slot printed antenna for triple‐frequency operation
Authors: Chen Wen‐Shan , Chang Wen‐Yen
Published: May 2008

This article proposed a design of a U‐shaped strip‐slot antenna for GSM900/DCS1800/WLAN/Bluetooth applications. The proposed antenna was fabricated on FR4 substrate and fed by 50‐Ω coaxial cable. The proposed antenna was first cut into U‐shaped strip to operate at higher frequency of 2.4 GHz for WLAN/BlueTooth applications. Furthermore, the other operation bands‐900 MHz and 1800 MHz for GSM900/DCS1800 applications have been achieved by inserted symmetric U‐shaped slot into the ground plane. Simulated and measured results are shown below. Details of the proposed antenna configuration and experimental results are also discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2219–2223, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23601
Microwave velocity and impedance tuning of traveling‐wave modulator using ion implantation for monolithic integrated photonic systems
Authors: Seo Sang‐Woo , Yan John , Baek Jong‐Hwa , Soares Francisco M. , Broeke Ronald , Pham Anh‐Vu , Yoo S. J. Ben.
Published: May 2008

We present performance improvement in InP traveling‐wave modulators (TWMs) using a periodic ion implantation on coplanar waveguide. Fabricated TWMs show the successful velocity and impedance tuning with return loss of lower than −12dB and reduced effective microwave refractive index of approximately 4 across the measured frequency range up to 50GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2151–2155, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23607
A dual‐mode bandpass filter with a wide stopband using a controllable bandstop structure
Authors: Hung Cheng‐Yuan , Weng Min‐Hang , Yang Ru‐Yuan
Published: May 2008

In this article, a bandpass filter with a wide stopband is proposed for the wireless local area network (WLAN) system. The filter is mainly composed of a dual‐mode bandpass filter (DM‐BPF) and a controllable bandstop structure (CBS). By using the CBS, multiple transmission zeros can be located on the spurious responses of the DM‐BPF. The design procedure is discussed in detail in this article. The designed filter is fabricated and measured. Measured results have a good agreement with the simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2214–2216, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23610
On‐chip spiral inductor with novel gradually changed structure
Authors: Liu Jing , Shi Yanling , Wen Xiuzhi , Chen Dawei , Luo Tian‐Xing , Huang Hao , Ye Hongbo , Wang Yong
Published: May 2008

On‐chip spiral inductors with sufficient quality factors are very important in many RF circuits. Based on the magnetic field intensity of a spiral inductor increasing gradually from outside to inside, this article presents a novel inductor structure with gradually changed metal width and space. Some design rules of this new structure have been obtained from a large number of data analyses. The sum of metal width and space of each coil is fixed while the ratio of the metal width to space is gradually reduced from outside to inside. Inductors have been fabricated and the obtained experimental results have verified the proposed design method. For a 7‐nH inductor on high‐resistivity silicon at 2.1 GHz, Q factor of 10 is 23.5% higher than the conventional inductor with fixed metal width and space, and is also 13.6% higher than the single gradually changed inductor with fixed space and gradually changed metal width. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2210–2213, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23611
Single‐layer bandpass active frequency selective surface
Authors: Kiani Ghaffer I. , Ford Kenneth L. , Esselle Karu P. , Weily Andrew R. , Panagamuwa C. , Batchelor John C.
Published: May 2008

A single‐layer, bandpass, active FSS is presented. It shows good angle of incidence stability for TE incidence, at the operating frequency of 2.45 GHz. It is based on circular loop aperture with each unit cell having four PIN diodes. A novel method for dc biasing is used. About 12 dB average variation in transmission loss, between ON and OFF states, has been experimentally achieved at 2.45 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2149–2151, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23615
Centralized lightwave radio‐over‐fiber system by only one phase modulator for DWDM optical millimeter‐wave generation
Authors: Chen Lin , Dong Ze , Lu Jia , Chun Wen Shuang
Published: May 2008

We have proposed and demonstrated a novel radio‐over‐fiber (ROF) architecture by using only one phase modulator and one optical filter to generate DWDM optical millimeter (mm) signals and realize wavelength reuse for upstream data connection. There is no additional laser source for the upstream data generation in the base station and no dc‐bias controller for phase modulator. By this method, we simplify the configuration of the DWDM ROF system and reduce the cost of the system. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2146–2149, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23616
Reduced splitting error in the ADI‐FDTD method using iterative method
Authors: Kong Ki‐Bok , Kim Jong‐Sung , Park Seong‐Ook
Published: May 2008

In this study, a new method is introduced to reduce the splitting error in the ADI‐FDTD method using iterative method. The proposed method includes two procedures. First we solve the procedure of ADI‐FDTD method and secondly a new iterative scheme is adopted. The improvement of reduced splitting error is investigated by numerical examples. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2200–2203, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23618
Efficient technique for two‐dimensional scattering center extraction and ISAR image formation
Authors: Shin Seung Yong , Myung Noh Hoon
Published: May 2008

This article presents efficient technique of two‐dimensional (2D) scattering center extraction and inverse synthetic aperture radar (ISAR) image formation of a target. The proposed technique uses a sparse scanning order conception and modified spatial smoothing preprocessing (MSSP). The MSSP is used to construct autocorrelation matrix. In general, 2D IFFT (inverse fast Fourier transform) is widely used to obtain 2D scattering center and ISAR image. This method is computationally efficient, but has drawbacks that are poor in terms of resolution. To overcome these shortcomings with the IFFT‐based method, various high‐resolution techniques were developed. The proposed algorithm enables us to provide exact scattering centers and ISAR image of a target. In order to show the performances of the proposed technique, we use backscattered field data of the ideal point scatterers and the F‐18 aircraft to estimate 2D scattering centers and obtain 2D ISAR image. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2173–2178, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23619
Discretely tunable single‐ and dual‐wavelength fiber ring laser using a fiber Bragg gratings based Fabry‐Perot filter
Authors: Zhou Jinlong , Xia Li , Dong Xiaopeng , Shum Ping
Published: May 2008

A Fabry‐Perot filter is realized by inscribing two identical 1 mm uniform Bragg gratings separated by 7.7 mm space in the hydrogen‐loaded photosensitive optical fiber. It is then incorporated with a tunable chirped fiber Bragg grating into a fiber ring cavity. Fourteen single‐wavelength lasings from 1552.186 nm to 1553.453 nm with average 97.5 pm spacing, and 13 pairs of dual‐wavelength lasings within the above wavelength range are achieved stably. This kind of laser will be very useful in applications requiring close‐spacing and tunable single‐ or dual‐wavelength components and systems. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2170–2173, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23620
1H and 13C NMR spectral assignments of some novel 2,4,6,8‐tetraaryl‐3,7‐diazabicyclo[3.3.1]nonan‐9‐one derivatives
Authors: Parthiban Paramasivam , Ramachandran Rajamanickam , Aridoss Gopalakrishnan , Kabilan Senthamaraikannan
Published: May 2008

The 1H and 13C NMR spectra of 2,4,6,8‐tetraaryl‐3,7‐diazabicyclo[3.3.1]nonan‐9‐ones (1–2), oximes (3–8) and O‐benzyl oximes (9–12) were recorded. The chemical shifts were unambiguously assigned using 1D and 2D NMR spectral data. The results clearly indicate that the compounds exist in chair‐boat conformation with equatorial and axial orientation of the aryl groups in the chair and boat forms, respectively. Since the molecules are flexible and dynamic in solution, the chair and boat forms are mutually interconvertible. In 3–12, because of the effect of oximation/oximination, all the protons in the heterobicyclic systems gave distinct signals except the benzylic protons of the boat form. In all synthesized compounds, the aryl group protons at C‐6,8 are shielded by the aryl groups at C‐2,4 and therefore appear in the lower frequency region than the aryl groups at C‐2,4. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of oocyte‐selective NLRP genes in rhesus macaque monkeys (Macaca mulatta)
Authors: McDaniel Patrick , Wu Xuemei
Published: May 2008

Oocyte‐selective genes control multiple aspects of female gamete development and preimplantation embryogenesis. Several key oocyte‐selective factors have been identified in mice recently; however, these factors are not well documented in more advanced species such as nonhuman primates. One of such oocyte‐selective factors is NLRP5 (NLR family, Pyrin domain containing 5), also known as Maternal Antigen That Embryos Require (MATER), which is required for preimplantation embryo development beyond the 2‐cell stage in mice. Human NLRP family contains 14 members. We identified 14 NLRP gene homologues and examined their spatial and temporal expression in rhesus macaque monkeys (Macaca mulatta). While all 14 NLRP genes are detectable in the macaque gonad, eight of them (NLRP2, 4, 5, 8, 9, 11, 13, and 14) are specifically or preferentially expressed in the ovary. In situ hybridization elucidated a specific oocyte expression pattern of the eight NLRP genes within the ovary. During the oocyte‐to‐embryo transition, seven of these oocyte‐selective NLRP transcripts (excluding NLPR2) are enriched in maturing oocytes and early preimplantation embryos but diminish upon embryo genome activation, indicating an exclusive maternal origin of these transcripts. Though functionally unknown, the spatial and temporal distribution of these oocyte‐selective NLRP genes implies important roles of the NLRP family in oogenesis and early embryo development in nonhuman primates. Mol. Reprod. Dev. 76: 151–159, 2009. © 2008 Wiley‐Liss, Inc.
New techniques for cartilage magnetic resonance imaging relaxation time analysis: Texture analysis of flattened cartilage and localized intra‐ and inter‐subject comparisons
Authors: Carballido‐Gamio Julio , Link Thomas M. , Majumdar Sharmila
Published: May 2008

MR relaxation time measurements of knee cartilage have shown potential to characterize knee osteoarthritis (OA). In this work, techniques that allow localized intra‐ and inter‐subject comparisons of cartilage relaxation times, as well as cartilage flattening for texture analysis parallel and perpendicular to the natural cartilage layers, are presented. The localized comparisons are based on the registration of bone structures and the assignment of relaxation time feature vectors to each point in the bone–cartilage interface. Cartilage flattening was accomplished with Bezier splines and warping, and texture analysis was performed with second‐order texture measures using gray‐level co‐occurrence matrices (GLCM). In a cohort of five normal subjects the performance and reproducibility of the techniques were evaluated using T1ρ maps of femoral knee cartilage. The feasibility of creating a mean cartilage relaxation time map is also presented. Successful localized intra‐ and inter‐subject T1ρ comparisons were obtained with reproducibility similar to that reported in the literature for regional T2. Improvement of the reproducibility of GLCM features was obtained by flattening the T1ρ maps. The results indicate that the presented techniques have potential in longitudinal and population studies of knee OA at different stages of the disease. Magn Reson Med 59:1472–1477, 2008. © 2008 Wiley‐Liss, Inc.
Longitudinal 3He and proton imaging of magnetite biodistribution in a rat model of instilled nanoparticles
Authors: Al Faraj Achraf , Lacroix Ghislaine , Alsaid Hasan , Elgrabi Dan , Stupar Vasile , Robidel Franck , Gaillard Sophie , Canet‐Soulas Emmanuelle , Crémillieux Yannick
Published: May 2008

Epidemiological and toxicological studies have provided evidence that accidentally inhaled nanosize ultrafine particles can induce chronic or acute health damage. MRI, being noninvasive, is able to assess the biodistribution and clearance of magnetically labeled nanoparticles induced by instillation or inhalation. We report 3He and proton MRI follow‐up of lung, liver, spleen, and kidney distribution of USPIO (ultrasmall superparamagnetic iron oxide) in a rat model. The sensitivity of the imaging technique to various concentrations of instilled magnetite suspension was first assessed in vivo (n = 12). A 2‐week longitudinal imaging study was then performed on animals (n = 7) instilled with a 0.5 mg magnetite solution. Hypointense and void signal regions associated with intrapulmonary USPIO were observed in the 3He ventilation images throughout the study, whereas no USPIO‐related proton signal intensity changes were found. Intrapulmonary magnetite nanoparticle confinement was confirmed by ex vivo iron assay and histological analysis. This study demonstrates that combined 3He and proton MRI enables noninvasive assessment of the distribution and clearance of magnetically labeled instilled nanoparticles. Magn Reson Med 59:1298–1303, 2008. © 2008 Wiley‐Liss, Inc.
A 128‐channel receive‐only cardiac coil for highly accelerated cardiac MRI at 3 Tesla
Authors: Schmitt Melanie , Potthast Andreas , Sosnovik David E. , Polimeni Jonathan R. , Wiggins Graham C. , Triantafyllou Christina , Wald Lawrence L.
Published: May 2008

A 128‐channel receive‐only array coil is described and tested for cardiac imaging at 3T. The coil is closely contoured to the body with a “clam‐shell” geometry with 68 posterior and 60 anterior elements, each 75 mm in diameter, and arranged in a continuous overlapped array of hexagonal symmetry to minimize nearest neighbor coupling. Signal‐to‐noise ratio (SNR) and noise amplification for parallel imaging (G‐factor) were evaluated in phantom and volunteer experiments. These results were compared to those of commercially available 24‐channel and 32‐channel coils in routine use for cardiac imaging. The in vivo measurements with the 128‐channel coil resulted in SNR gains compared to the 24‐channel coil (up to 2.2‐fold in the apex). The 128‐ and 32‐channel coils showed similar SNR in the heart, likely dominated by the similar element diameters of these coils. The maximum G‐factor values were up to seven times better for a seven‐fold acceleration factor (R = 7) compared to the 24‐channel coil and up to two‐fold improved compared to the 32‐channel coil. The ability of the 128‐channel coil to facilitate highly accelerated cardiac imaging was demonstrated in four volunteers using acceleration factors up to seven‐fold (R = 7) in a single spatial dimension. Magn Reson Med 59:1431–1439, 2008. © 2008 Wiley‐Liss, Inc.
Mn enhancement and respiratory gating for in utero MRI of the embryonic mouse central nervous system
Authors: Deans Abby E. , Wadghiri Youssef Zaim , Berrios‐Otero César A. , Turnbull Daniel H.
Published: May 2008

The mouse is the preferred model organism for genetic studies of mammalian brain development. MRI has potential for in utero studies of mouse brain development, but has been limited previously by challenges of maximizing image resolution and contrast while minimizing artifacts due to physiological motion. Manganese (Mn)‐enhanced MRI (MEMRI) studies have demonstrated central nervous system (CNS) contrast enhancement in mice from the earliest postnatal stages. The purpose of this study was to expand MEMRI to in utero studies of the embryonic CNS in combination with respiratory gating to decrease motion artifacts. We investigated MEMRI‐facilitated CNS segmentation and three‐dimensional (3D) analysis in wild‐type mouse embryos from midgestation, and explored effects of Mn on embryonic survival and image contrast. Motivated by observations that MEMRI provided an effective method for visualization and volumetric analysis of embryonic CNS structures, especially in ventral regions, we used MEMRI to examine Nkx2.1 mutant mice that were previously reported to have ventral forebrain defects. Quantitative MEMRI analysis of Nkx2.1 knockout mice demonstrated volumetric changes in septum (SE) and basal ganglia (BG), as well as alterations in hypothalamic structures. This method may provide an effective means for in utero analysis of CNS phenotypes in a variety of mouse mutants. Magn Reson Med 59:1320–1328, 2008. © 2008 Wiley‐Liss, Inc.
Quantitation with QUEST of brain HRMAS‐NMR signals: Application to metabolic disorders in experimental epileptic seizures
Authors: Rabeson H. , Fauvelle F. , Testylier G. , Foquin A. , Carpentier P. , Dorandeu F. , van Ormondt D. , Graveron‐Demilly D.
Published: May 2008

Quantitation of High Resolution Magic Angle Spinning (HRMAS) Nuclear Magnetic Resonance (NMR) signals enables establishing reference metabolite profiles of ex vivo tissues. Signals are often contaminated by a background signal originating mainly from macromolecules and lipids and by residual water which hampers proper quantitation. We show that automatic quantitation of HRMAS signals, even in the presence of a background, can be achieved by the semi‐parametric algorithm QUEST based on prior knowledge of a metabolite basis‐set. The latter was quantum‐mechanically simulated with NMR‐SCOPE and requires accurate spin parameters. The region of interest of spectra is a small part of the full spectral bandwidth. Reducing the computation time inherent to the large number of data‐points is possible by using ER‐Filter in a preprocessing step. Through Monte‐Carlo studies, we analyze the performances of quantitation without and with ER‐Filtering.

Applications of QUEST to quantitation of 1H ex vivo HRMAS‐NMR data of mouse brains after intoxication with soman, are demonstrated. Metabolic profiles obtained during status epilepticus and later when neuronal lesions are installed, are established. Acetate, Alanine, Choline and γ‐amino‐butyric acid concentrations increase in the piriform cortex during the initial status epilepticus, when seizures are maximum; Lactate and Glutamine concentrations increase while myo‐Inositol and N‐acetylaspartate concentrations decrease when neuronal lesions are clearly installed. Magn Reson Med 59:1266–1273, 2008. © 2008 Wiley‐Liss, Inc.
Single‐ or dual‐bolus approach for the assessment of myocardial perfusion reserve in quantitative MR perfusion imaging
Authors: Utz Wolfgang , Greiser Andreas , Niendorf Thoralf , Dietz Rainer , Schulz‐Menger Jeanette
Published: May 2008

A dual‐bolus protocol can overcome limitations due to T1‐induced MR signal attenuation and hence enables more accurate quantification of myocardial blood flow (MBF) by contrast enhanced MR perfusion imaging. The study explores potential benefits of the dual‐bolus technique for the assessment of myocardial perfusion reserve (MPR) over a standard single‐bolus protocol. Nineteen patients without obstructive coronary artery disease as assessed by cardiac catheterization underwent a stress‐rest MR perfusion study using a dual‐bolus protocol. Gd‐DTPA dosages of 0.005 and 0.05 mmol/kg of bodyweight were delivered as pre‐ and main‐bolus. For comparison arterial input curves where extracted from left ventricular cavity passage including both, pre‐bolus and main‐bolus data. Global and segmental MPR were determined from semiquantitative and from full quantitative measures of MBF. As a result good agreement between dual‐ and single‐bolus technique was found with relative differences of maximally 10% in global MPR estimates. For the dual bolus approach a significant relative decrease of 30% (P < 0.001) was found for the coefficient of segmental MPR variation, which may allow a more reliable detection of hypoperfused segments in clinical studies. Magn Reson Med 59:1373–1377, 2008. © 2008 Wiley‐Liss, Inc.
Minimizing acquisition time of arterial spin labeling at 3T
Authors: Fernández‐Seara María A. , Edlow Brian L. , Hoang Angela , Wang Jiongjiong , Feinberg David A. , Detre John A.
Published: May 2008

An improved arterial spin labeling (ASL) perfusion technique that combines pseudo‐continuous labeling and a T2*‐insensitive sequence (GRASE) with background suppression was used to acquire perfusion maps in normal volunteers and stroke patients. It is shown that perfusion measurements obtained in less than 1 min of scan time are reproducible, with a coefficient of variation of 7%. The perfusion maps generated from these data can be used to characterize the stroke lesion. Magn Reson Med 59:1467–1471, 2008. © 2008 Wiley‐Liss, Inc.
Analysis of double discharges in amyotrophic lateral sclerosis
Authors: Piotrkiewicz Maria , Kudina Lydia , Mierzejewska Jolanta , Hausmanowa‐Petrusewicz Irena
Published: May 2008

Double discharges of motor units (MUs) occurring during sustained voluntary muscle contractions are observed occasionally in healthy muscles and more frequently in disorders of the neuromuscular system. In healthy subjects, double discharges are generated in motoneurons (MNs) and are considered to be a sign of their increased excitability. Therefore, an analysis of their firing pattern may provide information on the state of MNs in neuromuscular diseases, particularly in amyotrophic lateral sclerosis (ALS), whose etiology remains to be disclosed. Firing patterns of MUs capable of firing double discharges were analyzed in brachial biceps of 14 patients with ALS (184 MUs) and 8 healthy control subjects (102 MUs). The incidence of MUs capable of firing double discharges was significantly higher in ALS patients (28.8%) than in controls (3.9%). The majority of doublet interval durations (range 4–8 ms) as well as firing patterns of doubling MUs did not differ between subject groups. Although our data confirm the hyperexcitability of the MN pool in ALS, analysis of firing characteristics of doubling MUs indicates that doublet generation is governed by the same mechanism as in controls, that is, by delayed depolarization. Our findings may provide insight into MN function in ALS. Muscle Nerve, 2008
Chronic sensorimotor polyradiculopathy with antibodies to P2: An electrophysiological and immunoproteomic analysis
Authors: Rojas‐Garcia Ricard , Gallardo Eduard , De La Torre Carolina , Sanvito Lara , Illa Isabel
Published: May 2008

In this study we report a patient with chronic progressive sensory ataxia, proximal weakness, immunoglobulin M (IgM) monoclonal gammopathy, and elevated protein levels in the cerebrospinal fluid, who showed a good response to prednisone. Electrophysiological study disclosed abnormalities predominantly of late responses (F waves and H reflexes), with no evidence of demyelination in the peripheral nerves, suggesting motor and preganglionic sensory nerve roots as the site of the lesion. An immune‐mediated pathogenesis was considered and, to identify possible target antigens, we performed bidimensional electrophoresis and a Western blot study. Based on the suspected lesion site, we used human anterior and posterior root extracts. We identified IgM reactivity against peripheral nerve myelin protein P2. Enzyme‐linked immunosorbent assay confirmed IgM reactivity toward one synthetic peptide from P2. To our knowledge, reactivity against P2 has not been reported previously in a paraproteinemic neuropathy. Furthermore, we demonstrated that bidimensional electrophoresis and Western blot of the tissue involved, as determined by clinical and electrophysiological studies, may be useful to establish clinical–immunological correlations in paraproteinemic neuropathies. Muscle Nerve, 2008
Satisfaction with urethral injection of Botulinum Toxin A for detrusor sphincter dyssynergia in patients with spinal cord lesion
Authors: Kuo Hann‐Chorng
Published: May 2008

Aims

To investigate satisfaction with urination quality of life (QoL) after treatment with urethral sphincter botulinum toxin A (BoNT‐A) injection for difficult urination in patients with spinal cord lesions and detrusor sphincter dyssynergia (DSD).

Methods

Thirty‐three patients with spinal cord lesion and DSD were treated with transurethral sphincter injection of 100 U of BoNT‐A (BOTOX) for the main symptom of difficult urination. The urodynamic parameters, QoL scores obtained using UDI‐6 and IIQ‐7 and general satisfaction and dissatisfaction were assessed.

Results

An overall satisfactory result was perceived by 60.6% of patients. Urodynamic parameters showed significant improvement in voiding detrusor pressure (45.7 ± 22.7 vs. 30.7 ± 15.5 cmH2O, P = 0.016), maximum flow rate (6.8 ± 5.7 vs. 9.2 ± 7.7 ml/sec, P = 0.047) and postvoid residual volume (PVR, 160 ± 124 vs. 75 ± 105 ml, P = 0.025). IIQ‐7 scores showed significant improvement (19.0 ± 2.4 vs. 17.1 ± 2.9, P = 0.001) but not in UDI‐6 scores (8.6 ± 2.7 vs. 7.9 ± 3.7, P = 0.252). Less difficult urination and less PVR needing clean intermittent catheterization were the major reasons for satisfaction, whereas increase in incontinence grade was the major reason for dissatisfaction in patients receiving urethral BoNT‐A injection.

Conclusion

This study found that urethral sphincter BoNT‐A injection for DSD does not prove convincing results in all patients and should be done only exceptionally in well‐chosen patients with spinal cord lesions. Dissatisfaction in the patients was mainly due to an increased incontinence grade that was not anticipated before urethral BoNT‐A injection. Neurourol. Urodynam. 27:793–796, 2008, © 2008 Wiley‐Liss, Inc.
Current Awareness in NMR in Biomedicine
Authors:   John Wiley & Sons, Ltd.
Published: May 2008

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of NMR in biomedicine. Each bibliography is divided into 11 sections: 1 Reviews; 2 General; 3 Technology; 4 Contrast Agents; 5 Brain and Nerves; 6 Neuropathology; 7 Cancer; 8 Cardiac, Vascular and Respiratory Systems; 9 Liver, Kidney and Other Organs; 10 Muscle and Orthopaedic; 11 Plants, Micro‐organisms and Parasites; 12 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
Creating positive change in community organizations: A case for rediscovering Lewin
Authors: Medley Barbara C. , Akan Obasi Haki
Published: June 2008

As nonprofits, especially those with a community mission, pursue developmental goals, they may benefit from various planning and analytical tools. This article explores an application of Kurt Lewin's planned change model to an assessment and revisioning process undertaken by a community‐based organization, indicating the ongoing usefulness of Lewin's work in the nonprofit sector. Using a case study approach, we examined the actions embarked on by the organization to address decreased funding and client losses. The Lewin model is overlaid to illustrate its value in structuring organizational decision making and development. The model is a three‐step process of unfreezing from old practices, moving and changing the organization into new directions based on formally identified needs, and refreezing into more effective organizational modes. When combined with other standard practices such as strategic planning, Lewin's model provides a practical and theoretically insightful tool for nonprofits wishing to refine their missions and programs and engage in successful organizational change.
Attitudes toward the acceptability of reasons for pregnancy termination due to fetal abnormalities among prenatal care providers and consumers in Israel
Authors: Dery Anat Mishori , Carmi Rivka , Vardi Ilana Shoham
Published: May 2008

Objectives/Background

Current prenatal diagnostic abilities confront parents and health professionals with complicated issues regarding termination of pregnancy (TOP) due to fetal abnormalities.

To assess and compare attitudes of consumers (women) and providers (health professionals) of prenatal care regarding TOP due to fetal abnormality.

To identify factors related to these attitudes.

Methods

The study was conducted in southern Israel. Consumers (596) were interviewed by phone 5–8 weeks postpartum. Health professionals (351) filled out a self‐administrated questionnaire.

Results

More than half of the interviewees approved of TOP due to mental retardation, death during infancy, severe physical disability and very low quality of life (in descending order). For each condition, care providers were significantly more supportive of TOP than women, and had far fewer hesitations. The hierarchy of ‘TOP acceptability’ was similar in both populations. Factors associated with women's attitudes were degree of religiosity, Ashkenazi origin and country of birth. Two approaches toward TOP were identified: ‘consistent’ versus ‘ad hoc’.

Conclusions

Prenatal care providers and consumers differ in their attitudes regarding acceptability of reasons for TOP. Care providers offering prenatal tests should be aware of their patients' attitudes, in order to guide informed decisions regarding the tests. Copyright © 2008 John Wiley & Sons, Ltd.
Congenital diaphragmatic hernia in a first‐trimester ultrasound aneuploidy screening program
Authors: Sepulveda Waldo , Wong Amy E. , Casasbuenas Alexandra , Solari Aldo , Alcalde Juan L.
Published: May 2008

Objectives

To review our experience with the prenatal detection of congenital diaphragmatic hernia (CDH) in fetuses presenting for ultrasound screening of chromosomal abnormalities in the first trimester.

Methods

As part of our first‐trimester ultrasound protocol, fetuses with a crown‐rump length between 45 and 84 mm underwent a limited anatomical assessment in conjunction with nuchal translucency thickness measurement and nasal bone assessment. Cases of CDH diagnosed prenatally or after delivery in this population were identified.

Results

Among the six cases of CDH detected (prevalence of 1 in 927), the first‐trimester ultrasound findings were abnormal in five fetuses (83%), including three with increased nuchal translucency only; one with increased nuchal translucency, an intrathoracic stomach, dextrocardia and a cephalocele; and one with normal nuchal translucency thickness and a small, complex intrathoracic mass later confirmed as the fetal stomach. The diagnosis of CDH was confidently made in the first trimester in one case, in the second trimester in three cases, and after birth in the remaining two cases.

Conclusion

The diagnosis of CDH in the first trimester is difficult, especially in those cases in which the defect is small or late migration of the abdominal viscera occurs. Therefore, screening for CDH in the first trimester is unlikely to be effective. Copyright © 2008 John Wiley & Sons, Ltd.
Carrier‐mediated transport of metformin across the human placenta determined by using theex vivoperfusion of the placental cotyledon model
Authors: Kovo Michal , Kogman Naomi , Ovadia Oded , Nakash Ishak , Golan Abraham , Hoffman Amnon
Published: May 2008

Objective

Metformin is a polar positively charged compound. The aim of the study was to characterize its permeability across the human placenta using theex vivoplacental perfusion model.

Methods

Selected cotyledons from term placentas were cannulated and dually perfused. Metformin (10 mg/L, 1000 mg/L) and a permeability reference, antipyrine (50 mg/L), were added to the maternal circulation. Samples from maternal and fetal compartments were analyzed for metformin and antipyrine by high performance liquid chromatography (HPLC). The permeation of metformin was also studied using the parallel artificial membrane permeation assay (PAMPA) that was designed to predict passive transcellular permeability of drugs.

Results

In this study, 15 complete placental perfusion experimental set‐ups were performed. The mean percent transport increased as metformin concentrations were raised and it was 11 ± 1.32 and 16.92 ± 0.98 for 10 mg/L and 1000 mg/L, respectively. The transport rate of metformin across the placenta was asymmetric yet, an active efflux against the gradient concentration could not be observed. Using the PAMPA assay, we confirmed that metformin does not cross by passive diffusion.

Conclusion

The data suggest that metformin permeability across the placenta is mediated by a carrier that transport cationic compounds bi‐directionally, with a higher transfer rate from the fetal to the maternal side. Copyright © 2008 John Wiley & Sons, Ltd.
A new linear viscoelastic model for emulsions and suspensions
Authors: Pal Rajinder
Published: May 2008

A new modified form of the Palierne model is proposed to describe the linear viscoelastic behavior of concentrated emulsions and suspensions. The proposed model takes into consideration the crowding effect and packing limit of particles. The model is verified using two sets of experimental data on the storage and loss moduli of emulsions and suspensions. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Diffusion‐controlled atom transfer radical polymerization with crosslinking
Authors: Yu Qiang , Qin Zhongqiong , Li Jinchun , Zhu Shiping
Published: May 2008

The reaction behavior of atom transfer radical polymerization (ATRP) with crosslinking was studied using di(meth)acrylates as the model network‐forming system. The kinetics was followed by differential scanning calorimetry (DSC). The structural evolution of the networks was investigated by gel permeation chromatography (GPC) and extraction/swelling measurements. The linear primary chains were obtained by hydrolysis of the networks and analyzed by viscometry. It was found that the polymerization proceeded in a controlled/living manner in an early stage of the reaction with the molecular weight of primary chains increasing linearly with vinyl conversion. However, deviations from the linearity occurred at high monomer conversions due to the network structure that severely restricted mobilities of catalyst/ligand complexes in the radical activation/deactivation. The onset and degree of deviation depended on crosslinking density. The diffusion‐controlled radical deactivation caused a mild autoacceleration in the polymerization rate. Adding excess Cu(II) to the system reduced the polymerization rate but improved the linear growth of primary chains that would facilitate the synthesis of networks of controlled microstructure. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Reactive compatibilization of biodegradable poly(lactic acid)/poly(ε‐caprolactone) blends with reactive processing agents
Authors: Harada Masaki , Iida Kouji , Okamoto Kazuaki , Hayashi Hideki , Hirano Koji
Published: May 2008

Poly(lactic acid) (PLA) blended with poly(ε‐caprolactone) (PCL) was prepared with various reactive processing agents. Four isocyanates‐lysine triisocyanate (LTI); lysine diisocyanate (LDI); 1,3,5‐tris(6‐isocyanatohexyl)‐1,3,5‐triazinane‐2,4,6‐trione (Duranate TPA‐100); 1,3,5‐tris(6‐isocyanatohexyl)biuret (Duranate 24A‐100)‐and an industrial epoxide‐trimethylolpropane triglycidyl ether (Epiclon 725)‐were used as reactive processing agents. PLA/PCL blended in the presence of LTI had the highest torque in a mixer test. The test specimens were prepared by injection molding. The mechanical properties, thermal properties, molecular weight, melt viscosity, phase behavior, and morphology were investigated using tensile strength, impact strength, differential scanning calorimetry, melt mass‐flow rate measurements, capillary rheometery, gel permeation chromatography, laser scanning confocal microscopy (LSCM), and visco‐elasticity atomic force microscopy (VE‐AFM). The impact strength increased considerably at 20 wt% PCL. The nominal tensile strain of PLA/PCL blended with LTI increased by 270%. The MFR values of PLA/PCL blends decreased with increasing LTI. Similar results were observed for shear viscosity. LSCM measurements showed that the diameters of PCL were dispersed about 0.4 μm in the presence of LTI. VE‐AFM showed that spherical particles with diameters of 50 nm were PCL‐rich domain. These results indicate that isocyanate groups of LTI react with both terminal hydroxyl or carboxyl groups of polymers, and the compatibility of PLA/PCL blends improves with LTI by reactive processing. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Role of core‐shell rubber particle cavitation resistance on toughenability of epoxy resins
Authors: Mafi Ehsan R. , Ebrahimi Morteza
Published: May 2008

The role of rubber particle cavitation resistance on toughening of epoxy resins is still unresolved. In this research, the role of rubber particle cavitation resistance was exclusively studied. Two types of core‐shell rubber (CSR) particles with different cavitation resistances were utilized for modifying epoxy resin. Matrix crosslink density (XLD) was varied by using nonstoichiometric amounts of hardener. Fracture toughness values of neat and CSR‐modified epoxy samples decreased with lowering of XLD via deviation from stoichiometric point. It was resulted by higher modulus and lower elongation at break of the nonstoichiometric samples, and also antiplasticization of epoxy networks resulted from suppression of β‐transition relaxation motions. In all XLDs, the CSR particles with higher core Tg and modulus yielded higher fracture energy. Results showed that core properties such as Tg and modulus of CSR particles had a significant effect on toughening of the epoxy networks. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Biaxial yielding of polypropylene/elastomeric polyolefin blends: Effect of elastomer content and thermal annealing
Authors: Fasce Laura A. , Pettarin Valeria , Marano Claudia , Rink Marta , Frontini Patricia M.
Published: May 2008

The yield behavior of commercial homopolymer polypropylene modified by elastomeric metallocene‐catalyzed polyolefin blends was investigated by carrying out uniaxial tension, uniaxial compression, plane strain compression, and simple shear mechanical tests. Investigation was performed using specimens machined from isotropic compression molded plates. The onset of yielding was determined by means of the residual strain method. Experimental data was fitted according to the two most popular yield criteria in the polymer field—modified Tresca and modified Von Mises criteria. Both criteria provided reasonable predictions of the yield onset locus despite the tendency of polymers to develop crazes under positive hydrostatic pressure. A generalized yield locus based on the modified Von Mises criterion and the Lazzeri and Bucknall relationship was constructed for PP/POE blends. In addition, for one blend composition the effect of the polypropylene matrix crystalline morphology—altered by thermal annealing—was investigated. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.
Effect of filler size distribution on the mechanical and physical properties of alumina‐filled silicone rubber
Authors: Zhou Wenying , Yu Demei , Wang Caifeng , An Qunli , Qi Shuhua
Published: May 2008

The properties of silicone rubber filled with three kinds of binary mixtures of alumina particles with different size distribution (i.e., 30 μm + 0.5 μm, 10 μm + 0.5 μm, and 5 μm + 0.5 μm) were investigated as a function of relative volume fraction of the 0.5 μm particles in the hybrid alumina (Vs) at a fixed total filler content of 55 vol%. The results indicate that each binary mixture of alumina‐filled silicone rubber exhibited improved thermal conductivity and tensile strength, and decreased dielectric constant, compared to a single particle size filler‐reinforced one, and the maximum improvements were obtained at the Vs ranging from 0.2 to 0.35; the coefficient of thermal expansion (CTE) of filled silicone rubber obviously reduced with increase in the Vs, whereas the elongation at break slightly decreased. At Vs = 0, the larger particles‐filled silicone rubber showed higher thermal conductivity, CTE, dielectric constant, and elongation at break, and lower tensile strength compared with the those of the smaller particles‐filled one. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Influence of compatibilizer precursor structure on the phase distribution of low density poly(ethylene) in a poly(ethylene terephthalate) matrix
Authors: Coltelli Maria‐Beatrice , Harrats Charef , Aglietto Mauro , Groeninckx Gabriel
Published: May 2008

In attempt to enhance the compatibility of PET/LDPE blends by using a proper functionalized polymer as third component, diethyl maleate (DEM)‐functionalized ultralow density poly(ethylene) (ULDPE‐g‐DEM) and styrene‐b‐(ethylene‐co‐1‐butene)‐b‐styrene triblock copolymer (SEBS‐g‐DEM) were prepared by radical functionalization in the melt. Immiscible PET/LDPE blends having compositions of 70/30 and 80/20 by weight were then extruded in the presence of 1–10% by weight of ULDPE‐g‐DEM and SEBS‐g‐DEM as compatibilizer precursors and ZnO (0.3% by weight) as transesterification catalyst. In both cases, evidences about the occurring of compatibilization between the two immiscible phases, thanks to the studied reactive processes, were obtained. Moreover, the phase distribution and particle size of blends were deeply investigated. Completely different kinds of phase morphology were achieved, as ULDPE‐g‐DEM stabilized a dispersed phase morphology, whereas SEBS‐g‐DEM favored the development of a cocontinuous phase morphology. The observed differences are tentatively explained onthe basis of reactivity and physical features of polymers. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.
A study on a primitive artificial esterase model: reactivity of a calix[4]resorcinarene bearing carboxyl groups
Authors: Cevasco Giorgio , Galatini Andrea , Pirinççioğlu Necmettin , Thea Sergio , Williams Andrew
Published: May 2008

The host molecule octacarboxymethyl calix[4]resorcinarene 1 catalyses the hydrolysis of substituted phenyl N‐methylpyridinium‐4‐carboxylate esters 3a–f by complexation followed by intracomplex reaction via an anhydride intermediate. The reactivity in the presence of 1 is higher than that of the background at low pH; at high pH an inversion of reactivity occurs, the background becomes predominant since the host inhibits hydrolysis of the esters. The reactivity of esters 3a–f complexed with the host suffers little change in effective charge on the phenolic oxygen (−0.15 units) in contrast with the changes observed in alkaline hydrolysis (−0.28 units) and in the hydrolysis of the model monoaryl glutarate esters (‐1.02 units). The less negative effective charge in the transition state for host 1 catalysis compared with that in the glutarate case is ascribed to stronger solvation by water molecules in the complex compared with that due to water molecules in the bulk solvent.
The role of stereoelectronic interactions in the conformational isomerism of some phosphorus‐containing model compounds
Authors: Freitas Matheus P. , Rittner Roberto , Tormena Cláudio F. , Abraham Raymond J.
Published: May 2008

The rotational isomerism of model phosphorus‐containing compounds was evaluated by using theoretical methodologies. The trans rotamer of chloromethylphosphonic acid dichloride (1) was found to be the prevailing form in the gas phase and in non‐polar solvents, with an inverse behaviour from chloroform solution. Although the use of direct spin–spin coupling constants (SSCCs) do not apply for the quantitative determination of conformers in 1, due to the small dependence of J with conformation, the observed measurements and calculated individual couplings suggest that the gauche conformer is progressively stabilized with increasing the solvent polarity. In addition, theoretical calculations at the CBS‐Q level for the corresponding phosphine of 1 (compound 2) showed the gauche rotamer as the prevailing one in the isolated state. Natural Bond Orbital (NBO) analysis indicated that steric and electrostatic effects rule the rotational isomerism of 1, while the anomeric effect nP → σ*CCl also plays an important role on the conformational equilibrium of 2. Copyright © 2008 John Wiley & Sons, Ltd.
Photochemistry of thiophene‐S‐oxide derivatives
Authors: Heying Melanie J. , Nag Mrinmoy , Jenks William S.
Published: June 2008

Photolysis of substituted thiophene‐S‐oxides in solution results in the formation of either the corresponding thiophene or furan, in addition to uncharacterized materials. No good rationalization is available for the choice of which pathway may predominate, but it is demonstrated that the photolysis of 2,5‐bistrimethylsilylthiopene‐ S‐oxide produces O(3P) in the same manner as the well‐established photolysis of dibenzothiophene‐S‐oxide. Copyright © 2008 John Wiley & Sons, Ltd.