bluuebunny/crossref_metadata_2025 huggingface dataset:
Ambiguity in Assignment of Near Infrared Vibrational Bands for Polymerisation Monitoring of Epoxy System
Authors: Lachenal Gilbert , Stevenson Isabelle , Durand Alexandra , Seytre G. , Bertrand D.
Published: May 2008

The curing process of epoxy affects the chemical structure of the final network so mechanical and physical properties of the polymeric matrix for a composite may be modified according to the polymerisation conditions. This paper describes the ambiguity in assignment of reference bands to follow the cure of poly‐epoxy reactive systems using a laboratory‐made system which allows the coupling of dielectric analysis and Fourier Transform Near Infrared Spectroscopy (FTNIR). The dielectric measurements were obtained using interdigitated electrode. In situ monitoring of extent of reaction was carried out from room temperature up to 160 °C using fibre‐optic FTNIR spectroscopy. For the DGEBA/MCDEA system the epoxy band at 6060 cm−1 was chosen in preference to the band at 4530 cm−1 as representative of the epoxy function evolution during polymerisation because a small unknown peak probably due to the hardener appears in the 4530 cm−1 region. The bands at 4620 and 4680 cm−1 assigned to aromatic combination bands and widely used as reference bands are not unique for this formulation hence the band at 5980 cm−1 is used as reference. The Principal Components Analysis (PCA) shows clearly also that the bands at 4620 and 4680 cm−1 vary during the polymerisation. Surprisingly, the band at 4530 cm−1 is equivalent to the one at 6060 cm−1 to calculate the conversion rate. It is probably due to the fact that the hardener band near 4530 cm−1 follows the same behaviour as the epoxy band at 4530 cm−1.
Application of FTIR Microscopy in Combinatorial Experimentation on Polymer Blends
Authors: l'Abee Roy , Li Weizhen , Goossens Han , van Duin Martin
Published: May 2008

Summary: A novel combinatorial, high‐throughput experimentation (HTE) setup has been developed, which allows for rapid mapping of the phase behavior of blends of homopolymers and block copolymers. The principle is based on the preparation of composition (ϕ)‐temperature (T) gradient films. Linear ϕ gradients were obtained over a large composition range, as shown by FTIR microscopy. The applicability of this combinatorial approach was demonstrated by studying the phase behavior of a poly(styrene‐co‐acrylonitrile) (SAN)/poly(methyl methacrylate‐co‐ethyl acrylate) (PMMA‐EA) blend with varying EA content and a poly(styrene‐b‐butadiene‐b‐methyl methacrylate) (SBM) triblock copolymer.
Activation of the retinoblastoma tumor suppressor mediates cell cycle inhibition and cell death in specific cervical cancer cell lines
Authors: Bourgo Ryan J. , Braden Wesley A. , Wells Susanne I. , Knudsen Erik S.
Published: May 2008

High‐risk human papilloma virus (HPV) encodes two oncoproteins, E6 and E7, which are vital to viral replication and contribute to the development of cervical cancer. HPV16 E7 can target over 20 cellular proteins, but is best known for inactivating the retinoblastoma (RB) tumor suppressor. RB functions by restraining cells from entering S‐phase of the cell cycle, thus preventing aberrant proliferation. While it is well established that HPV16 E7 facilitates the degradation of the RB protein, the ability of the RB pathway to overcome E7 action is less well understood. In this study the RB‐pathway was activated via the overexpression of the p16ink4a tumor suppressor or ectopic expression of an active allele of RB (PSM‐RB). While p16ink4a had no influence on cell cycle progression, PSM‐RB expression was sufficient to induce a cell cycle arrest in both SiHa and HeLa cells, HPV positive cervical cancer cell lines. Strikingly, this arrest led to the downregulation of E2F target gene expression, which was antagonized via enhanced HPV‐E7 expression. Since downmodulation of E7 function is associated with chronic growth arrest and senescence, the effect of PSM‐RB on proliferation and survival was evaluated. Surprisingly, sustained PSM‐RB expression impeded the proliferation of SiHa cells, resulting in both cell cycle inhibition and cell death. From these studies we conclude that active RB expression can sensitize specific cervical cancer cells to cell cycle inhibition and cell death. Thus, targeted therapies involving activation of RB function may be effective in inducing cell death in cervical cancer. © 2008 Wiley‐Liss, Inc.
Design of triple‐band filters by using asymmetric parallel‐coupled lines
Authors: Zhao Hui , Cui Tie Jun
Published: May 2008

In this article we design triple‐band parallel‐coupled bandpass filters by using asymmetric parallel‐coupled lines which have more degrees of freedom to satisfy the coupling rules in the triple bands. Stepped‐impedance resonator is used with its controllable high‐order resonance frequencies. Two examples of filters are presented, in which simulation and measurement results have good agreements. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2054–2058, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23553
All‐optical reconfigurable microwave photonic signal processor
Authors: Chan E. H. W.
Published: May 2008

An all‐optical reconfigurable high resolution microwave photonic signal processor is presented. It is based on a 2 × 1 electro‐optic modulator and an active‐fiber Bragg‐grating‐pair filter. Experimental results demonstrate a sharp bandpass filter response and a narrow stopband notch filter response which can be obtained by controlling the optical sources. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1989–1991, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23557
A practical feeder for differential elliptical antennas in ultra wideband applications
Authors: Mehdipour Aidin , Mohammadpour‐Aghdam Karim , Kashani‐Khatib M. R. , Faraji‐Dana Reza
Published: May 2008

In antenna design, feeding structures may cause improper effects on the performance of antennas. In this article, a practical and efficient feeding structure for differential elliptical antennas (DEA) using the combination of CPW feed lines and a vertical balun transformer is presented and fabricated. Using the designed feed, return loss (VSWR), radiation pattern, and frequency/time domain characteristics of the antenna are evaluated numerically and experimentally. Besides a satisfactory agreement between simulation and experimental results, it is observed that the designed feeding structure works properly without deteriorating the antenna performance. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2103–2107, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23560
Design of quasi‐Yagi antennas using an ultra‐wideband balun
Authors: Woo Dong Sik , Kim Young Gon , Kim Kang Wook , Cho Young Ki
Published: May 2008

In this study, a systematic and simplified design procedure for quasi‐Yagi antennas is presented. The design is based on the simple field and impedance matching among antenna components. This new antenna design is possible due to the newly developed ultra‐wideband balun. Two types of wideband quasi‐Yagi antennas are successfully designed and implemented in Ku‐ and Ka‐band with frequency bandwidths of 53.2% and 29.1%, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2068–2071, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23563
Wideband integrated monopole slot antenna for WLAN/WiMAX operation in the mobile phone
Authors: Wong Kin‐Lu , Lai Peng‐Yu
Published: May 2008

A promising design of the wideband integrated monopole slot antenna for WLAN/WiMAX operation in the mobile phone is presented. The antenna is integrated at one corner of the system circuit board of the mobile phone and consists of two portions, one on‐board slotted portion and one add‐on portion. The add‐on portion is printed on a small FR4 substrate as a surface‐mount element, which is vertically mounted and connected to the on‐board slotted portion to form as a monopole slot antenna. This integrated monopole slot antenna occupies a small volume in the mobile phone and shows a very wide bandwidth covering WLAN operation in the 2400–2484 MHz band and WiMAX operation in the 2500–2690/3300–3700 MHz bands. Detailed results of impedance and radiation characteristics of the proposed antenna are presented and discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2000–2005, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23566
Dual‐frequency circularly‐polarized microstrip antenna with switchable polarization sense
Authors: Wu Jia‐Feng , Row Jeen‐Sheen , Wong Kin‐Lu
Published: May 2008

A dual‐frequency circularly‐polarized (CP) microstrip antenna capable of switching polarization sense is presented. The antenna is fed by a microstrip line through aperture coupling. First, it is found that a CP mode can be excited when the radiating patch is square and an open‐ring slot is used as the coupling aperture. Then, by truncating the radiating patch, another CP mode can be obtained. The two CP modes have reversed polarization senses, and their operating frequencies are different. For the proposed dual‐frequency CP microstrip antenna, two prototypes with frequency ratios of 1.07 and 1.23 were constructed, and voltage‐controlled diodes are employed to achieve the electrical switching between the two CP modes. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2125–2128, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23569
MEMS‐reconfigurable bandpass filter
Authors: Corchia Laura , Monti Giuseppina , Tarricone Luciano
Published: May 2008

This article presents a MEMS‐based bandpass filter with a reconfigurable frequency response. The proposed device consists of a stub‐loaded Branch‐Line Coupler in artificial transmission line technology, resulting in a very compact structure. Furthermore, by using a micro electro mechanical system resistive switch, a reconfigurable frequency response has been obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2096–2099, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23570
A wideband microstrip antenna with symmetric radiation patterns
Authors: Kasabegoudar Veeresh G. , Vinoy K. J.
Published: May 2008

A wideband microstrip antenna using a coplanar capacitive feed with nearly 50% impedance bandwidth has been realized on a stacked air‐dielectric substrate with only one metal layer above the ground plane. In this article an approach of modifying the patch shape is proposed to obtain symmetric radiation patterns in the entire frequency band of this antenna. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1991–1995, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23575
Very‐low‐cost copper‐wire antenna for 2.4‐GHz WLAN operation
Authors: Chou Jui‐Hung , Su Saou‐Wen
Published: May 2008

A very‐low‐cost copper‐wire antenna, easily fabricated by bending a single 70‐mm‐long copper wire two times, for WLAN operation in the 2.4‐GHz band (2400–2484 MHz) is presented. The antenna has a very simple structure and is easily fed by using a 50‐Ω mini‐coaxial cable. A prototype of the proposed antenna with the overall dimensions 40 mm × 5 mm is constructed and tested. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2107–2109, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23589
UWB lowpass filter with novel comb CMRC
Authors: Zhang F. , Li C. F.
Published: May 2008

A novel comb compact microstrip resonant cell (CCMRC) is first developed. The compact configuration presents ultra wide stopband and excellent slow‐wave characteristics. A UWB lowpass filter, consisting of three CCMRCs connected in series, is designed and fabricated. The proposed filter has the merits of low insertion loss in the passband, sharp, deep, and wide rejection in the stopband and compact size. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2077–2079, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23590
Adaptive TRX isolation scheme by using TX leakage canceller at variable frequency
Authors: Jung Jin‐Woo , Roh Hyoung‐Hwan , Kwak Ho‐Gil , Sub Jeong Myoung , Park Jun‐Seok
Published: May 2008

This article presents a TX leakage cancellation scheme for UHF RFID readers. A prototype is implemented on a UHF RFID reader board, which includes a circulator, directional coupler, microcontrol unit (MCU)‐controlled variable attenuator, and phase shifter. The difference between a conventional TX leakage canceller and this new one is that, reflected signals caused by mismatches between the front‐end and the antenna are included; in addition, high isolation is supplemented at variable frequencies. About 10% of the frequency range is recovered by the best suited parameter values that provide a predetermined process of MCU; and thus, peak isolation characteristics are constantly guaranteed at each center frequency by phase‐shifted signal generation that follows references stored in MCU. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2043–2045, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23592
Generation of dispersion‐free millimeter wave signals by double sideband modulation and vestigial sideband filtering techniques
Authors: Yun Xu Lan , Guo Yu Jian , Yun Xu Hong
Published: May 2008

Fiber dispersion in standard single mode fiber (SSMF) limits the maximum delivery distance for the optical millimeter (mm)‐wave signals generated by double sideband modulation and vestigial sideband filtering. We propose and experimentally demonstrate a novel scheme to generate mm‐wave signals without dispersion limitation. The power penalty for 2.5‐Gbit/s mm‐wave signals carried by 40‐GHz radio‐frequency after transmission over 80‐km SSMF is smaller than 0.5 dB. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2158–2161, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23605
Improved EBG‐loaded waveguide low‐pass filter
Authors: Tang Yi‐ming , Yu Yan‐min , Wu Wen
Published: May 2008

A new design of electromagnetic band gap (EBG) waveguide low‐pass filter (LPF) loaded with double‐array is described to improve the stopband characteristics. Broader gapband width, about 2‐GHz broader than the traditional filters, greater stopband attenuation, and moderate passband insert loss (0.5 dB) can be obtained. Theoretical and measured results are in good agreement. The filter can be employed for the out‐of‐passband clutter rejection of traditional filters. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2090–2093, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23608
Compact reconfigurable circularly polarised microstrip antenna with asymmetric cross slots
Authors: Hyun D.‐H. , Baik J.‐W. , Kim Y.‐S.
Published: May 2008

A single microstrip‐fed compact reconfigurable circularly polarized (CP) microstrip antenna with variable asymmetric cross slots using PIN diodes is proposed. It can be implemented by unequal length of cross slots on the patch, which are switched on and off using PIN diodes. Right hand circular polarization (RHCP) is obtained as diode‐off, while left hand circular polarization (LHCP) is excited when diodes are on. This proposed antenna can be switched flexibly under the changeable environment of wave propagation and used in the system required polarization diversity. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2217–2219, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23609
Wide‐slot waveguide antenna on LTCC technology
Authors: Ooi B. L. , Ang Irene , Shan X. C. , Lu Albert , Fieck R. , Hristov H. D.
Published: May 2008

A wide‐slot waveguide antenna implemented on low‐temperature cofired ceramic technology is presented. The overall antenna is excited by aperture coupling. The design is simulated and validated by experimental measurement. The measured result shows that a 10‐dB return loss has been achieved across the bandwidth from 2.6 GHz to 12.8 GHz, thus amounting to 132.5%. The measured radiation pattern of the proposed antenna is also presented and discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2181–2184, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23613
Automatic quantification of local and global articular cartilage surface curvature: Biomarkers for osteoarthritis?
Authors: Folkesson Jenny , Dam Erik B. , Olsen Ole F. , Karsdal Morten A. , Pettersen Paola C. , Christiansen Claus
Published: May 2008

The objective of this study was to quantitatively assess the surface curvature of the articular cartilage from low‐field magnetic resonance imaging (MRI) data, and to investigate its role in populations with varying radiographic signs of osteoarthritis (OA), cross‐sectionally and longitudinally. The curvature of the articular surface of the medial tibial compartment was estimated both on fine and coarse scales using two different automatic methods which are both developed from an automatic 3D segmentation algorithm. Cross‐sectionally (n = 288), the surface curvature for both the fine‐ and coarse‐scale estimates were significantly higher in the OA population compared with the healthy population, with P < 0.001 and P ≪ 0.001, respectively. For the longitudinal study (n = 245), there was a significant increase in fine‐scale curvature for healthy and borderline OA populations (P < 0.001), and in coarse‐scale curvature for severe OA populations (P < 0.05). Fine‐scale curvature could predict progressors using the estimates of those healthy at baseline (P < 0.001). The inter‐scan precision was 2.2 and 6.5 (mean CV) for the fine‐ and coarse scale curvature measures, respectively. The results showed that quantitative curvature estimates from low‐field MRI at different scales could potentially become biomarkers targeted at different stages of OA. Magn Reson Med 59:1340–1346, 2008. © 2008 Wiley‐Liss, Inc.
MagA is sufficient for producing magnetic nanoparticles in mammalian cells, making it an MRI reporter
Authors: Zurkiya Omar , Chan Anthony W.S. , Hu Xiaoping
Published: May 2008

Magnetic resonance imaging (MRI) is routinely used to obtain anatomical images that have greatly advanced biomedical research and clinical health care today, but the full potential of MRI in providing functional, physiological, and molecular information is only beginning to emerge. In this work, we sought to provide a gene expression marker for MRI based on bacterial magnetosomes, tiny magnets produced by naturally occurring magnetotactic bacteria. Specifically, magA, a gene in magnetotactic bacteria known to be involved with iron transport, is expressed in a commonly used human cell line, 293FT, resulting in the production of magnetic, iron‐oxide nanoparticles by these cells and leading to increased transverse relaxivity. MRI shows that these particles can be formed in vivo utilizing endogenous iron and can be used to visualize cells positive for magA. These results demonstrate that magA alone is sufficient to produce magnetic nanoparticles and that it is an appropriate candidate for an MRI reporter gene. Magn Reson Med 59:1225–1231, 2008. © 2008 Wiley‐Liss, Inc.
Improving the pharmacokinetic parameter measurement in dynamic contrast‐enhanced MRI by use of the arterial input function: Theory and clinical application
Authors: Yang Xiangyu , Liang Jiachao , Heverhagen Johannes T. , Jia Guang , Schmalbrock Petra , Sammet Steffen , Koch Regina , Knopp Michael V.
Published: May 2008

One of the most powerful features of the dynamic contrast‐enhanced (DCE) MRI technique is its capability to quantitatively measure the physiological or pathophysiological environments assessed by the passage of contrast agent by means of model‐based pharmacokinetic analysis. The widely used two‐compartment pharmacokinetic model developed by Brix and colleges fits tumor data well in most cases, but fails to explain the biexponential arterial input function. In this work, this problem has been attacked from a theoretical point of view, showing that this problem can be solved by adopting a more realistic model assumption when simplifying the general solutions of the two‐compartment pharmacokinetic equations. Pharmacokinetic parameters derived from our model were demonstrated to have comparative tissue specificity to Ktrans from Larsson's model, better than those from Brix's model and the empirical area‐under‐the‐curve (AUC). Tissue‐type classifier constructed with the arterial input function–decomposed kep‐kpe pair from our model was also demonstrated to have superior performance than any other classifier based on DCE‐MRI pharmacokinetic parameters or empirical AUC. The feature that this classifier has a near‐zero false‐negative rate makes it a highly desirable tool for clinical diagnostic and response assessment applications. Magn Reson Med 59:1448–1456, 2008. © 2008 Wiley‐Liss, Inc.
Adapting the clinical MRI software environment for real‐time navigation of an endovascular untethered ferromagnetic bead for future endovascular interventions
Authors: Chanu Arnaud , Felfoul Ouajdi , Beaudoin Gilles , Martel Sylvain
Published: May 2008

A dedicated software architecture for a novel interventional method allowing the navigation of ferromagnetic endovascular devices using a standard real‐time clinical MRI system is shown. Through a specially developed software environment integrating a tracking method and a real‐time controller algorithm, a clinical 1.5T Siemens Avanto MRI system is adapted to provide new functionality for potential automated interventional applications. The proposed software architecture was successfully validated through in vivo controlled navigation inside the carotid artery of a swine. Here we present how this MRI‐upgraded software environment could also be used in more complex vasculature models through the real‐time navigation of a 1.5 mm diameter chrome steel bead in two different MR‐compatible phantoms with flowless and quiescent flow conditions. The developed platform and software modules needed for such navigation are also presented. Real‐time tracking achieved through a dedicated positioning method based on an off‐resonance excitation technique has also been successfully integrated in the software platform while maintaining adequate real‐time performance. These preliminary feasibility experiments suggest that navigation of such devices can be achieved using a similar software architecture on other conventional clinical MRI systems at an operational closed‐loop control frequency of 32 Hz. Magn Reson Med 59:1287–1297, 2008. © 2008 Wiley‐Liss, Inc.
Ross syndrome associated with cytomegalovirus infection
Authors: Nagane Yuriko , Utsugisawa Kimiaki
Published: May 2008

We report a 40‐year‐old woman who developed Ross syndrome (impairment of sweating and thermoregulation, tonic pupils, and hyporeflexia) associated with cytomegalovirus (CMV) infection. Her serum CMV IgM and IgG antibody titer levels were elevated. Along with clinical improvement, a gradual decrease of her elevated CMV IgM antibody titer level was seen with a continued increase in her CMV IgG antibody titer level. The CMV IgM antibody titer was also positive in the cerebrospinal fluid. Muscle Nerve, 2008
Muscle ultrasound in neuromuscular disorders
Authors: Pillen Sigrid , Arts Ilse M. P. , Zwarts Machiel J.
Published: May 2008

Muscle ultrasound is a useful tool in the diagnosis of neuromuscular disorders, as these disorders result in muscle atrophy and intramuscular fibrosis and fatty infiltration, which can be visualized with ultrasound. Several prospective studies have reported high sensitivities and specificities in the detection of neuromuscular disorders. Although not investigated in large series of patients, different neuromuscular disorders tend to show specific changes on muscle ultrasound, which can be helpful in differential diagnosis. For example, Duchenne muscular dystrophy results in a severe, homogeneous increase of muscle echo intensity with normal muscle thickness, whereas spinal muscular atrophy shows an inhomogeneous increase of echo intensity with severe atrophy. A major advantage of muscle ultrasound, compared to other imaging techniques, is its ability to visualize muscle movements, such as muscle contractions and fasciculations. This study reviews the possibilities and limitations of ultrasound in muscle imaging and its value as a diagnostic tool in neuromuscular disorders. Muscle Nerve, 2008
Changes in intracellular action potential profile affect parameters used in turns/amplitude analysis
Authors: Arabadzhiev Todor I. , Dimitrov George V. , Chakarov Vichren E. , Dimitrov Alexander G. , Dimitrova Nonna A.
Published: May 2008

The influence of changes in the intracellular action potential (IAP) spatial profile on motor unit potentials (MUPs), number of turns per second (NTs), and mean turn amplitude were simulated and analyzed. We show why measurement of NTs was “the best indicator of neurogenic affection” and why the lower diagnostic yield of turns/amplitude analysis in myopathy could be due to changes in IAP shape caused by elevated free calcium concentration. The results explain the complications observed when interference electromyographic signals obtained during high levels of isometric contractions were analyzed. We show that, in contrast to earlier assumptions, the effect of increased IAP spike duration on NTs was stronger than that of a decrease in muscle fiber propagation velocity (MFPV). The decrease in the NTs could occur without a drop‐out of MUs and/or a decrease in their firing rates, and without a change in MFPV and synchronous firing. Muscle Nerve, 2008
Bilateral drop foot secondary to a primary tumor in the conus medullaris
Authors: Makridou Alexandra , Argyriou Andreas A. , Karanasios Panagiotis , Makris Nicolaos
Published: May 2008

Intramedullary tumors of the spinal cord are rare neoplasms that can be associated with severe neurological and functional handicaps. To our knowledge, we describe for the first time the case of a male patient who developed bilateral drop foot as an initial manifestation of a primary tumor in the conus medullaris of the spinal cord, probably an astrocytoma. Muscle Nerve, 2008
A novel SNaPshot assay to detect the mdx mutation
Authors: Budowle Sarah A. , Gonzalez Suzanne , Budowle Bruce , Eisenberg Arthur J. , Grange Robert W.
Published: May 2008

The mdx mouse is an animal model for Duchenne muscular dystrophy (DMD). In order to evaluate possible treatments and to carry out genetic studies, it is essential to distinguish between mice that carry the dystrophic (mutant) or wild‐type (wt) allele(s). The current amplification‐resistant mutation system (ARMS) assay is labor intensive and yields false negatives, which reduces its efficiency as a screening tool. An alternate assay based on single‐nucleotide polymorphism (SNP) primer extension technology (i.e., SNaPshot) is described. The SNaPshot assay has been optimized to identify both wild‐type and mutant alleles, providing a robust, potentially automatable assay for high‐throughput analysis. Muscle Nerve 37: 731–735, 2008
Lambert–Eaton syndrome with large‐cell neuroendocrine carcinoma of the lung
Authors: Grommes Christian , Preston David C. , Al‐Kadhimi Zaid , Alshekhlee Amer
Published: May 2008

Lambert–Eaton syndrome (LES) is an immune‐mediated disorder of the presynaptic neuromuscular junction due to the blocking effect of the voltage‐gated calcium channel (VGCC) antibodies. Small‐cell lung cancer (SCLC) is the most common cause of LES. We report an unusual case of LES associated with large‐cell neuroendocrine carcinoma (LCNEC) of the lung. In this case, clinical symptoms of LES predated the diagnosis of LCNEC by 6 years. After tumor resection, the patient experienced clinical and electrophysiological improvement. In addition, he had a decrease in VGCC antibody titer from 130 to 80 pmol/L. The onset of LES can be prolonged, and tumor surveillance should continue in these cases. Muscle Nerve 37: 786–789, 2008
Management of neurogenic bladder patients in the Netherlands: do urologists follow guidelines?
Authors: Rikken Berend , Blok Bertil F.M.
Published: May 2008

Aims

Preventive measurements are obligatory for optimal treatment of neurogenic bladder patients. We investigated Dutch urological practice in neurogenic bladder patients in relation to the available guidelines on neurogenic bladder.

Methods

A 12‐point survey was sent to all 304 certified urologists of the Dutch Urological Association in July 2007. Management of urinary tract infections (UTI), follow‐up of the lower and upper urinary tract and treatment techniques were topics of inquiry.

Results

The response rate was 46% of which 94% were involved in treatment of neurogenic bladder patients. Follow‐up was performed every 6 or 12 months in 86%, urine analysis respectively in 85% and upper urinary tract imaging with ultrasound in 60%; only 12% routinely repeated urodynamics. Uncomplicated UTI was treated for 7.1 days in women and 9.2 days in males. Eighteen percent used the EAU guidelines on neurogenic bladder frequently, 35% did occasionally and 47% did not use them at all. Urologists, that used these guidelines frequently, treated asymptomatic UTIs significantly less frequent in patients on intermittent catheterization (5% vs. 25%; P = 0.008); no difference was found in frequency of follow‐up, urine analysis, surveillance of upper urinary tract, use of routine urodynamics, and availability of treatment techniques. Video urodynamics, the golden standard, was used by only 11% of the adult urologists.

Conclusion

The majority of Dutch urologists is involved in the treatment of neurogenic bladder, which suggests a less prominent role for specialized centers. Furthermore, urodynamics are not performed routinely. These observations are contrary to the recommendations of the available guidelines. Neurourol. Urodynam. 27:758–762, 2008, © 2008 Wiley‐Liss, Inc.
Adaptive grid based on geometric conservation law level set method for time dependent PDE
Authors: Soheili Ali R. , Ameri Maryam A.
Published: May 2008

A new method for mesh generation is formulated based on the level set functions, which are solutions of the standard level set evolution equation with the Cartesian coordinates as initial values (Liao et al. J Comput Phys 159 (2000), 103–122; Osher and Sethian J Comput Phys 79 (1988), 12; Sethian, Level set methods and fast marching methods, Cambridge University Press, 1999; Di et al. J Sci Comput 31 (2007), 75–98). The intersection of the level contours of the evolving functions form a new grid at each time. The velocity vector in the evolution equation is chosen according to the Geometric Conservation Law (GCL) method (Cao et al., SIAM J Sci Comput 24 (2002), 118–142.). This method has precise control over the Jacobian of transformation because of using the GCL method. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Internet use among adolescent and young adults (AYA) with cancer
Authors: Schiffman Joshua D. , Csongradi Eric , Suzuki Lalita K.
Published: May 2008

Background

The Internet serves as an important resource for adult cancer patients, but little is known about Internet use among adolescent and young adults (AYA) with cancer. The aims of this study were to describe (1) cancer‐specific websites which AYA with cancer visit and (2) Internet features desired by AYA on cancer‐specific websites and how many current AYA cancer websites contain these features.

Procedure

Individual phone interviews were conducted with a convenience sample of 16 AYA with cancer from across North America in June 2005. Content analysis of these interviews were coded and validated for desired website features. Current AYA cancer websites were identified on the Internet and the features on these sites were compared to the features desired by our sample.

Results

Favorite websites visited by AYA with cancer (cancer‐related and unrelated) were identified along with current Internet use. Twenty‐one distinct cancer website features desired by AYA with cancer were described. Twenty‐seven unique AYA cancer websites were found on the Internet during May–June 2006. Each site contained 7.7 (SD = 2.7) of the 21 features identified by participants as desirable, but the highest ranked features did not occur in the majority of these websites.

Conclusions

AYA with cancer indicate that they prefer to visit cancer websites that contain cancer‐related information, provide the ability to chat with AYA with cancer, and offer some type of game. Although many websites exist for AYA with cancer, few individual sites contain the web features identified as most desired by AYA with cancer. Pediatr Blood Cancer 2008;51:410–415. © 2008 Wiley‐Liss, Inc.
Severe chronic refractory immune thrombocytopenic purpura during childhood: A survey of physician management
Authors: Neunert Cindy E. , Bright Brianna C. , Buchanan George R.
Published: May 2008

Background

Physician attitudes regarding management of children with severe chronic immune thrombocytopenic purpura (ITP) have not been recently characterized.

Procedure

We designed a survey of members of the American Society of Pediatric Hematology‐Oncology (ASPHO) that described a 5‐year‐old female with ITP for 1 year who was unresponsive to steroids, IVIG, and anti‐D immune globulin and having frequent epistaxis causing interference with her daily activities. A 13‐item questionnaire evaluated physician decision‐making in this setting.

Results

Two hundred and ninety‐seven surveys (35% response rate) were returned, and 295 were evaluable. Thirty‐three percent of respondents stated that they would recommend splenectomy for such a child. Of those who would not recommend splenectomy, 67% reported that they would instead treat with rituximab. If initial drug therapy failed, 47% would proceed with splenectomy. Those who reported treating with rituximab initially were more likely to recommend splenectomy following failure than those who preferred other drug therapy (P < 0.0001).

Conclusions

Physician management of patients with chronic ITP is diverse. With the advent of new treatments such as rituximab and thrombopoetic agents it is critically important to compare their cost, adverse effects and efficacy with splenectomy in order to optimally guide treatment practices. Pediatr Blood Cancer 2008;51:513–516. © 2008 Wiley‐Liss, Inc.
Long‐term outcome of childhood acute lymphoblastic leukemia treated in China
Authors: Tang Yongmin , Xu Xiaojun , Song Hua , Yang Shilong , Shi Shuwen , Wei Jian
Published: May 2008

Background

To retrospectively determine the treatment outcome and causes of treatment failure of ALL children treated in a single institution at East China.

Procedure

Between January 1998 and October 2004, 346 newly diagnosed ALL patients ≤16 years were admitted to our hospital. Of these, 248 patients received modified National Protocol of Childhood ALL in China 1997 (NPCAC97) for at least 2 weeks of treatment and were eligible for protocol evaluation.

Results

Among the 346 newly diagnosed patients, 167 (48.3%) stopped treatment either at diagnosis or during therapy. The abandonment rates for urban area group (UAG) and rural area group (RAG) were 25.3% and 57.3%, respectively (P < 0.0001). The 5‐year event‐free survival (EFS) rate for the entire cohort was 38.5 ± 2.7%. For 248 evaluable patients, the remission rate was 97.2%. The 5‐year EFS and overall survival (OS) rates were 70.7 ± 3.6% and 82.1 ± 3.0%, respectively. The 5‐year EFS for standard‐risk group (n = 196) was significantly higher than that of high‐risk group (n = 52) (75.9 ± 3.9% vs. 50.7 ± 8.0%, P = 0.0002). Prognostic factor analysis showed that poor response to remission induction therapy and a poor socioeconomic status were predictive for an inferior outcome.

Conclusion

Abandonment of chemotherapy was the most common cause of treatment failure, which was strongly related to poor socioeconomic status and financial support. For patients who could adhere to the treatment protocol, a relatively good outcome was achieved. Pediatr Blood Cancer 2008;51:380–386. © 2008 Wiley‐Liss, Inc.
In vivomodel to determine fetal‐cell enrichment efficiency of novel noninvasive prenatal diagnosis methods
Authors: Ponnusamy S. , Mohammed N. , Ho S. S. Y. , Zhang H. M. , Chan Y. H. , Ng Y. W. , Su L. L. , Mahyuddin A. P. , Venkat A. , Chan J. , Rauff M. , Biswas A. , Choolani M.
Published: May 2008

Objective

To develop anin vivomodel to determine fetal‐cell enrichment efficiency of novel noninvasive prenatal diagnosis methods.

Methods

Efficiency of our three‐step enrichment protocol was determinedin vitrobefore fetal nucleated red blood cells (FNRBCs) were enriched from first‐trimester maternal blood samples collected from the same patients pre‐ and postsurgical termination of pregnancy (TOP) (n= 10). FNRBCs enriched were identified using embryonic ε‐globin immunocytochemistry and chromosomal fluorescencein situhybridization.

Results

We recovered 37% of spiked FNRBCs (95% confidence interval (CI) 28.5–45.6;n= 8) inin vitroexperiments. We show a consistent threefold increase in the number of ε + FNRBCs in maternal blood obtained immediately post‐TOP (p= 0.005). A mathematical relationship was derived: observed number of pretermination primitive FNRBCs = 0.6 + 0.31 (coefficient between pretermination/post‐termination primitive FNRBCs, 95% CI 0.12–0.49;p= 0.005) × observed number of post‐termination primitive FNRBCs (R2= 0.65).

Conclusion

Our data demonstrate that maternal blood obtained immediately post‐TOP would be a goodin vivomodel to determine the enrichment efficiency of novel protocols and methods for noninvasive prenatal diagnosis. Copyright © 2008 John Wiley & Sons, Ltd.
Prediction of fiber orientation in a rotating compressing and expanding mold
Authors: Wang J. , Silva C.A. , Viana J.C. , van Hattum F.W.J. , Cunha A.M. , Tucker C.L.
Published: May 2008

In the rotating/compressing/expanding mold (RCEM), one mold wall can expand, compress, and rotate during injection molding, thus offering opportunities to control the thermomechanical history of a polymer and its microstructure. A computer simulation of flow and fiber orientation in RCEM was developed. The predictive model extends the generalized Hele‐Shaw formulation to account for compression/expansion and rotation of the mold wall, and uses the Folgar–Tucker model for fiber orientation predictions. A 20% GF polypropylene was molded under various molding conditions. The predicted fiber orientation distributions were compared with experiments. The model compares favorably with experiments, provided that the fiber orientation equation is modified by a strain‐reduction factor that slows the transient development of fiber alignment. The effect of fountain flow on orientation must also be included to correctly predict fiber orientation near the mold walls, mainly for the case of stationary and linear motions of the mold surface. Compression or expansion of the mold has only a small effect on fiber orientation, but rotation of the mold dramatically changes the orientation, causing fibers to align in the tangential direction across the entire thickness of the molding. This rotation action perturbs the fountain flow and becomes the dominant factor affecting fiber alignment across the entire cavity thickness. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.
Linear and nonlinear melt‐state viscoelastic properties of polypropylene/organoclay nanocomposites
Authors: Nazockdast Ehssan , Nazockdast Hossein , Goharpey Fatemeh
Published: May 2008

Rheological behavior of polypropylene (PP)/organoclay nanocomposites varying in compatibilizer (PP‐g‐MA) and organoclay concentration was investigated. The samples were prepared by melt intercalation method in an internal mixer. The wide angle X‐ray diffraction patterns and results of rheological measurements showed that the compatibilizer had strong influence in increasing the interlayer spacing. The observed low frequency liquid‐like to solid‐like transition and apparent yield stress in simple shear flows, along with convergence of transient shear stress to nonzero values in stress relaxation after the cessation of flow experiments, were found to be consistent with formation of a physical network in quiescent conditions which could be easily ruptured with applying low shear rates. The values of stress overshoot strain in flow reversal experiments were independent of shear rate, organoclay, and compatibilizer content. From the results of frequency sweep experiments in different nonlinear strain amplitudes it was shown that extended Cox‐Merz analogy was valid in nonlinear dynamic deformations while the shear viscosity showed positive deviation from this analogy with higher deviations at lower shear rates. Results of storage modulus recovery and flow reversal experiments at different shear rates suggested that network structure is reformed with a much slower rate compared to the rotational relaxation of organoclay platelets. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Nanocomposites from plasticized high‐amylopectin, normal and high‐amylose maize starches
Authors: Mondragón Margarita , Mancilla Juana E. , Rodríguez‐González Francisco J.
Published: May 2008

Three types of maize starch with different amounts of amylose and amylopectin were used to prepare plasticized starch/clay nanocomposite films by casting. Studies by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that the intercalation/exfoliation of the plasticized starch molecules took place into the clay galleries for the three types of starch. However, the plasticized waxy starch molecules were the easiest of them all to be intercalated/exfoliated, which was reflected in the highest increment of the stress at peak of these nanocomposites. Moreover, the lowest water uptake was showed by the plasticized high‐amylose starch/clay nanocomposites. It was concluded that varying contents of amylose and amylopectin influenced the formation of intercalated/exfoliated clay structures and also affected the interactions of clay with water. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Hard coatings on polycarbonate plate by sol‐gel reactions of melamine derivative, PHEMA, and silicates
Authors: Shin Young Jae , Oh Mee Hye , Yoon Yeo Seong , Shin Jae Sup
Published: May 2008

Hard coatings were deposited on a polycarbonate plate using a sol‐gel process with a melamine derivative, PHEMA, and silicates, and examined as potential substitutes for glass in cars. Poly(2‐hydroxyethyl methacrylate) was partially functionalized with (3‐isocyanatopropyl)triethoxysilane, and the synthesized polymer was used to form a coating solution with methylated poly(melamine‐co‐formaldehyde), tetraethoxysilane, and methyltriethoxysilane. The coatings on the polycarbonate plate were deposited using a sol‐gel process. Precoating with poly(methyl methacrylate) was carried out to improve the adhesive strength of the coating. The optimum conditions and formulation to obtain excellent physical properties of the coating were determined. Smooth coatings with the hardness of a 3H class pencil, excellent abrasion resistance, and transparency were formed. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Macroindentation of polymers
Authors: Guglielmotti Alessandro , Quadrini Fabrizio , Squeo Erica Anna
Published: May 2008

Macroindentation tests were performed by means of a flat cylindrical indenter on high‐density polyethylene (HDPE) and polyamide 66 (PA66). Commercial sheets were acquired for both materials, and specimens were extracted for differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermal recovery tests. In this way, the fabrication effect was correctly identified in terms of degradation, orientation, and mechanical performance. Specimens were also prepared for tensile tests, which were performed for comparison with indentation experiments. Indentation tests were carried out on the external sheet surfaces at different indenter diameters (1 and 2 mm) and test rates (from 0.1 to 20 mm/min). A very high correlation was found between the tensile test and indentation results at the different test rates. In particular, the indentation stress at fixed depth was a linear function of the tensile yield stress, depending only on the indenter diameter and not on the material type. Moreover, a threshold value for the thickness for a correct comparison among samples having different dimensions is discussed. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Preparation and characterization of melt‐processed polycarbonate/multiwalled carbon nanotube composites
Authors: Wu Tzong‐Ming , Chen Erh‐Chiang , Lin Yen‐Wen , Chiang Ming‐Feng , Chang Gwo‐Yang
Published: May 2008

This study describes the preparation of polycarbonate (PC)/multiwalled carbon nanotube (MWCNT) composites by melt processing the PC and PC/MWCNT master batch at 260°C. The PC/MWCNT master batch was prepared using ultrasonic mixing the carboxylic acid containing MWCNT and PC in a tetrahydrofuran (THF) solution. The HRTEM images of PC/MWCNT master batch and PC/MWCNT nanocomposites show that the MWCNT is well separated and uniformly distributed in the PC matrices. Mechanical properties of the fabricated nanocomposites measured by dynamic mechanical analysis indicate significant improvements in the storage modulus when compared with that of pure PC matrix. The conductivities of 2 and 5 wt% PC/MWCNT nanocomposites are more than four and seven orders in magnitude higher than that of PC without MWCNT, respectively. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Synthesis and properties of polybenzoxazine modified polyurethanes as a new type of electrical insulators with improved thermal stability
Authors: Yeganeh Hamid , Razavi‐Nouri Mohammad , Ghaffari Mehdi
Published: May 2008

A new class of electrical insulating materials with improved thermal stability was prepared from combination of polybenzoxazine with epoxy terminated polyurethane prepolymer (EPU). EPU was prepared by the reaction of glycidol with NCO‐terminated urethane prepolymer. The prepolymer was prepared from polycaprolactone polyol (molecular weight 1000), and hexamethylene diisocyanate. Bisphenol‐A and aniline were used for preparation of benzoxazine monomer. Mode of reactions and optimum curing condition were determined by DSC and FTIR analysis. Upon these analysis as well as DMTA findings, formation of interpenetrating polymer networks was suggested for blends consisted different weight ratios of two components. Viscoelastic behavior, mechanical, thermal, and electrical properties of the prepared samples was studied and their relation to the chemical structure and composition of blends were elucidated. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers