bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing recognition of early Parkinsonism in the community
Authors: Höglinger Günter U. , Rissling Ida , Metz Aline , Ries Vincent , Heinermann Anne , Prinz Helge , Spieker Sybille , Deuschl Günter , Baum Erika , Oertel Wolfgang H.
Published: May 2004

Because Parkinsonism is underdiagnosed in the community, we have validated screening modalities in the field setting and developed a screening procedure to enhance recognition of undiagnosed patients. In a first survey, we identified suspect cases among patients consulting 9 general practitioners (GPs) over a 3‐week period using in parallel: (1) a published questionnaire; (2) a standardized examination by the GPs; (3) clinical impression of the GPs; or (4) pre‐established diagnoses. Parkinsonism was ascertained by two neurologists with a 1‐year follow‐up and FP‐CIT‐SPECT. In total, 1,411 patients consulted the GPs, 1,030 participated in the study, 87 possible cases were identified by at least one of four screening modalities, 12 suffered from Parkinsonism, and 4 of these 12 were de novo cases. Statistical analysis demonstrated that with appropriate evaluation, the questionnaire is highly sensitive and excludes most nonaffected persons, and that the GPs' clinical impression is more specific. We therefore tested in a second survey the efficacy of a serial screening, starting with the questionnaire, followed by a standardized GP evaluation, and then by neurological examination. Of 1,353 participants seen by 9 GPs during a 3‐week period, 5 de novo cases were identified. This simple screening protocol significantly enhances recognition of incipient Parkinsonism. © 2004 Movement Disorder Society
Semiquantitative study of current coffee, caffeine, and ethanol intake in essential tremor cases and controls
Authors: Louis Elan D. , Jurewicz Eva C. , Applegate Lakeisha , Luchsinger Jose A. , Factor‐Litvak Pam , Parides Michael
Published: May 2004

There are several reasons to study caffeine, coffee, and ethanol intake in essential tremor (ET) patients. ET patients also might modify their use of these beverages because of their effects on tremor. Intake of caffeine, coffee, and ethanol has not been quantified in a group of ET patients. Our objective is to use a semiquantitative food frequency questionnaire to compare current daily intake of coffee, caffeine, and ethanol in ET patients and controls. A total of 130 ET cases were patients at the Neurological Institute of New York, and 175 controls were ascertained by random digit dialing. Caffeine (in milligrams) and ethanol (in grams) intake were calculated from a semiquantitative food‐frequency questionnaire. Mean daily caffeine intake in patients was 138.4 versus 246.6 mg in controls; medians were 101.1 versus 175.5 mg (P < 0.001). Mean daily ethanol intake in patients was 8.2 versus 6.2 gm in controls; medians were 2.4 versus 1.9 gm (P = 0.89). Cases drank less coffee than controls, but drank similar amounts of tea, soft drinks, fruit juices, and milk. Daily caffeine intake was not correlated with tremor severity or duration. ET patients consumed less caffeine than did controls, which is likely to be a dietary modification in response to tremor. The observation that caffeine consumption was not correlated with tremor severity raises the additional possibility that lower caffeine consumption in ET patients may not exclusively be a response to tremor. A prospective study is needed to explore whether decreased caffeine consumption is a risk factor for ET. © 2004 Movement Disorder Society
Drug adherence in Parkinson's disease
Authors: Leopold Norman A. , Polansky Marcia , Hurka Marcia R.
Published: May 2004

:Physicians modify drug schedules in response to their patients' clinical responses. Failure to relieve patients' symptoms or the emergence of drug‐related side effects may reflect nonadherence to a prescribed drug schedule rather than incorrect therapeutic physician decisions. Using a medication questionnaire and a computerized medication event monitoring system (MEMS) to monitor medication use, nonadherence of drug use was examined in subjects with Parkinson's disease (PD). We report that prescription nonadherence in PD subjects was common and approximated that reported in other chronic diseases. During a 28‐day observation period, only 4 of 39 subjects had complete schedule adherence, i.e., no missed, extra, or mistimed doses. Using a questionnaire, 24.3% of subjects acknowledged missing any doses but the computerized MEMS recorded that 51.3% of subjects missed at least one dose per week and 20.5% of subjects missed three or more doses per week. Mistiming of doses was admitted by 73% of subjects but 82.1% had recorded mistimed doses. Of multiple sociodemographic and disease‐related items examined, only gender and level of education were statistically related to nonadherence. © 2004 Movement Disorder Society
SAR affected by shapes and electrical properties of the human head exposed to a cellular phone
Authors: Chen Hsing‐Yi , Yang Han‐Peng
Published: May 2004

The local maximum specific absorption rate (SAR) induced in spherical, cubical, coarse, and realistic human‐head models exposed to a cellular phone is investigated using the finite‐difference time‐domain (FDTD) method at 900 and 1800 MHz, respectively. These four human‐head models each have greatly different shapes but almost the same volume. Obtained local maximum SARs induced in these four human‐head models for homogeneous cases are found to have an average differences of about 15% and 12% at 900 and 1800 MHz, respectively. A comparison of SARs induced in the realistic human‐head model for homogeneous and inhomogeneous cases is also made. It is found that the local maximum SAR induced in the homogeneous human‐head model is larger than that induced in the inhomogeneous human head model. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 1–4, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20189
Electrically and mechanically tunable waveguide filter
Authors: Mias C. , Tsakonas C.
Published: May 2004

A novel, hybrid, electrically and mechanically tunable band‐stop waveguide filter is presented. The filter consists of a dielectric substrate on which a ring microstrip element is etched. The mechanical tuning range (the maximum band‐stop frequency that can be attained) is shown to be limited by the distance of the ring element from the conducting waveguide walls. This limitation is overcome by introducing electrical tuning, which is achieved by incorporating varactor diodes on the microstrip ring element. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 13–15, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20192
Band‐rejection and bandpass filters based on mechanically induced long‐period fiber gratings
Authors: Chen Kai , Sheng Qiuqin , Dong Xiaoyi
Published: May 2004

We present a novel method to fabricate fiber filters based on mechanically induced long‐period fiber gratings. Transmission spectra can be tailored by external pressures or by introducing a phase‐shift. As an example, the filter was used to flatten the spectral output from an Er‐doped superfluorescent fiber source. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 15–17, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20193
Antenna far‐field pattern reconstruction using equivalent currents and genetic algorithms
Authors: Pérez J. R. , Basterrechea J.
Published: May 2004

A method for computing the far‐field pattern of an antenna under test (AUT) from near‐field data is presented. Based on the equivalence principle, the AUT is replaced by equivalent magnetic surface currents, whose components are optimized using microgenetic algorithms. Results of reconstructed far‐field patterns from synthetic near‐field samples, a comparison to the approach using classical methods, and an analysis of the method's performance and limitations are included. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 21–25, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20195
Face recognition with transmissive liquid crystal panels
Authors: Chen Chulung , Chang Wen‐Yung
Published: May 2004

A technique for facial‐image recognition, based on the nonzero‐order joint‐transform correlator constructed with liquid‐crystal spatial light modulators (LCSLMs), is introduced. The method of Lagrange multipliers is utilized to design the reference function. We also add some noise in training images to investigate the performance. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 31–34, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20197
Hybrid GB and PO analysis of electromagnetic radiation/scattering from large reflector antennas with tapered impedance surfaces
Authors: Chou Hsi‐Tseng , Tuan Shih‐Chung , Hsiao Yu‐Ting
Published: May 2004

A hybrid scheme combining Gaussian beam (GB) and physical optics (PO) approaches is presented for an efficient analysis of reflector antennas with tapered‐impedance edge boundaries. The reflecting surface is divided into an interior portion with uniform impedance and a smooth boundary, where the GB approach can be employed, and an exterior portion of tapered impedance, which is analyzed by the PO approach. The high efficiency of the GB analysis potentially accelerates the entire analysis, as compared with the case in which only PO is employed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 34–37, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20198
Dual‐frequency planar inverted‐L antenna with circular‐sided patch
Authors: Chi Gaoming , Li Binhong , Qi Dongsheng
Published: May 2004

The design of a dual‐frequency planar inverted‐L antenna with a circular‐sided patch is described. The proposed antenna exhibits good dual‐frequency characteristics with the frequency ratio ranging from 1.70 to 1.98. Measured results of the performance of the antenna are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 40–41, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20200
Overcoming chromatic dispersion effects with enhanced RF gain using the phase detuning technique in an SOA cascaded optical single‐sideband transmission
Authors: Koo Bon‐Jo , Lee Ui‐Soo , Lee Seok , Han Sang‐Kook
Published: May 2004

A new technique to improve analog optical‐transmission performance using an optical single‐sideband (SSB) system with cascaded semiconductor optical amplifier (SOA) has been proposed. Our 92‐km transmission experiment shows that this technique does not show any chromatic‐dispersion effects and also gives larger RF gain compared to the conventional SSB modulated signal. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 42–43, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20201
Compact folded line bandstop and lowpass filters
Authors: Peddibhotla Harish , Settaluri Raghu K.
Published: May 2004

Compact multiple‐coupled folded line bandstop and lowpass filter structures are presented in this paper. A common design procedure is used to design both types of filters. The procedure for obtaining the reduced two‐port network parameters is described. The effect of mutual coupling among the lines, curved‐line sections, and interconnecting lengths of sections are taken into account in order to obtain the network parameters. The filter designs have been validated by using full‐wave EM simulation, as well as by comparison with the measurements. The distinct advantages of the folded‐line filter designs are a compact footprint and realizable physical dimensions. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 44–46, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20202
Full‐wave analysis of industrial microwave applicators: TE modes
Authors: Lohr C. , Pribetich P. , Stuerga D.
Published: May 2004

In this paper, full‐wave analysis of the TE modes of an industrial cylindrical microwave applicator is presented. The dispersion characteristics and fields configurations are shown. These results are obtained by a numerical simulation based on the residue theory. The authors have obtained particular modes called loop modes, which have a complex propagation constant that describes a loop within the complex plane. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 46–50, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20203
De‐embedding techniques for embedded microstrips
Authors: Song J. M. , Ling F. , Blood W. , Demircan E. , Sriram K. , Flynn G. , To K.‐H. , Tsai R. , Li Q. , Myers T. , Petras M. , Dengi A.
Published: May 2004

Three parameters are needed to model symmetrical adapters, but not enough equations can be found to solve them. The proposed two‐impedance model with one shunt and one series impedance gives consistent results when applied to three different lengths of embedded microstrip transmission lines. This model can be used with more complicated structures than the single‐impedance model. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 50–54, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20204
A monolithic 1.57/5.25‐GHz concurrent dual‐band low‐noise amplifier using InGaP/GaAs HBT technology
Authors: Lu Shey‐Shi , Lin Yo‐Sheng , Lee Bo‐Wei
Published: May 2004

A monolithic concurrent dual‐band low‐noise amplifier (LNA) using InGaP/GaAs HBT technology is demonstrated for the first time. The LNA provides narrowband gain and matching simultaneously at both 1.57‐GHz (GPS) and 5.25‐GHz (ISM) bands. It consumes only 15‐mW power and achieves transducer gains (S21) of 25.3 and 14.3 dB, input return losses (S11) of 6.8 and 11.5 dB, reverse isolation (S12) of −30.8 and −32.2 dB, and noise figures of 2.55 and 4.5 dB at these two bands, respectively. The performance at 5.25 GHz is comparable with the 2.45/5.25‐GHz concurrent dual‐band CMOS LNA with a bonding wire as the gate inductor using 0.35‐m CMOS technology1. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 58–60, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20206
Computational modeling of supercontinuum generation in fused silica by a femtosecond laser pulse of a few optical cycles
Authors: Hovhannisyan David , Stepanyan Komitas
Published: May 2004

The numerical solution of a wave equation describing the propagation of the laser pulse of a few optical cycles in fused silica is obtained. Our numerical simulations closely follow the published experimental data. A shifting of the spectrum peak of the broadened pulse, depending on the input‐pulse central wavelength, is observed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 60–64, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20207
High‐gain broadband optical‐waveguide amplifiers
Authors: Chen Haiyan , Liu Yongzhi , Dai Jizhi , Yang Yapei
Published: May 2004

A novel wideband and high‐gain waveguide‐amplifier structure, which consists of a folded geometry erbium‐ytterbium co‐doped phosphate glass waveguide integrated with a cascaded multilayer medium thin‐film filter (CMMTFF), is proposed. This CMMTFF consists of some different filter‐unit cells with different central wavelengths and bandwidths, and each of them can suppress a certain gain peak at a specific wavelength. The gain characteristics of this new optical amplifiers is obtained. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 64–66, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20208
Wide‐tuning‐range K‐band microwave‐photonic VCO using an all‐optical heterodyne scheme
Authors: Kwak Noh‐Min , Huh Hyeongjun , Jeong Heeseong , Cho Kyuman
Published: May 2004

This paper presents an all‐optical technique for providing a wide‐tuning‐range K‐band microwave‐photonic (MWP) voltage‐controlled oscillator (VCO). The frequency‐tuning range and gain of the VCO are 16 GHz and 25 MHz/mV, respectively. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 66–68, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20209
An omnidirectional planar microstrip antenna with low sidelobes
Authors: Bancroft Randy , Bateman Blaine
Published: May 2004

An omnidirectional printed planar microstrip antenna with low sidelobes is described. The radiation pattern of this antenna is analyzed numerically using the finite‐difference time‐domain (FDTD) method and compared with the measurements of a prototype. The driving point is unbalanced, which allows the antenna to be fed directly with a coaxial cable. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 68–69, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20210
A dual‐band strip‐sleeve monopole antenna fed by CPW
Authors: Cheng C. H. , Lv W. J. , Chen Y. , Zhu H. B.
Published: May 2004

A dual‐band strip‐sleeve monopole antenna fed by a coplanar waveguide (CPW) is presented. The antenna is designed to operate at 900 and 1800 MHz in a vehicular telephone. It is printed on a dielectric substrate and may be integrated with a microwave circuit manufactured on the CPW. It has been investigated numerically and experimentally. The results show that the designed antenna can provide satisfactory performance for GSM/DCS systems, including a sufficiently wide‐frequency band and a good radiation pattern. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 70–72, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20211
Extension of Hodgkinson's model for optical characterization of columnar thin films
Authors: Chiadini Francesco , Lakhtakia Akhlesh
Published: May 2004

An extension of Hodgkinson's model for the principal refractive indexes and column‐inclination angle of a columnar thin film against the vapor‐incidence angle is presented for an extraordinary refractive index relevant for many optical applications. Not only do the principal refractive indexes depend quadratically on the vapor incidence angle, but the extraordinary refractive index does as well. This model is expected to be valid for chiral sculptured thin films as well. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 72–73, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20212
Study of optical heterodyne mixing characteristics in an A1InAs/GaInAs transferred‐substrate double heterojunction bipolar transistor
Authors: Kwak N. M. , Kim H. J. , Kim H. T. , Choi W. J. , Cho K.
Published: May 2004

The beat‐frequency dependency of the optical heterodyne mixing characteristics of a transferred‐substrate A1InAs/GaInAs double heterojunction bipolar transistor (DHBT) have been investigated from 1 to 25 GHz in 1‐GHz steps at a center wavelength of 1319 nm. The experimental results show a high‐speed but low‐responsivity response followed by a low‐speed but high‐responsivity response. The 3‐dB bandwidth of the low‐speed response is 3 GHz. Various ways of increasing the high‐frequency responsivity are discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 74–77, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20213
Group velocity, negative and ultra‐high index of refraction in photonic band gap materials
Authors: Ojha S. P. , Srivastava Sanjeev K.
Published: May 2004

This paper shows that inside photonic band gap (PBG) materials the effective index of refraction neff, defined in terms of group velocity, becomes negative in a certain range of frequencies. Also, near the photonic‐band edge the effective index of refraction neff attains exceptionally high values, which are greater than the refractive indices of the materials (n1 and n2) used. This is related to the anomalous behaviour of group velocity, which becomes negative in a certain range and approaches zero near the photonic‐band edge. PBG material with a modified index of refraction has applications in the system of lasing without inversion and can also be used in construction of a perfect lens and other optical devices. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 82–87, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20216
Relationships of sexual imposition, dyadic trust, and sensation seeking with sexual risk behavior in young Urban women
Authors: Jones Rachel
Published: May 2004

This study was designed to examine the relationships of sexual imposition, dyadic trust, and sensation seeking with HIV sexual risk behavior in 257 young urban women. Interviews were conducted using Audio Computer‐Assisted Self‐Interview (ACASI). Hierarchical multiple regression revealed that sexual imposition, dyadic trust, and sensation seeking explained 18.3% of the variance in sexual risk behavior. Although sexual imposition was positively related to sexual risk, pressure to satisfy a male partner sexually was more common than physical coercion. Dyadic trust was negatively related, indicating that women engaged in sexual risk behavior with men they distrusted. Sensation seeking was positively related to sexual risk. Findings suggest the need for enhancing awareness of non–sexually imposing relationship alternatives and incorporating thrill and excitement in health promotion messages. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:185–197, 2004
Indomethacin and ibuprofen preserve gastrocnemius muscle mass in mice bearing the colon‐26 adenocarcinoma
Authors: McCarthy Donna O. , Whitney Pamela , Hitt Andrew , Al‐Majid Sadeeka
Published: May 2004

Skeletal muscle wasting is a prominent feature of cancer cachexia and involves decreased muscle protein synthesis and increased activity of the ubiquitin‐proteasome pathway of protein degradation. We report that both indomethacin and ibuprofen improved body weight and weight of the gastrocnemius muscle in tumor‐bearing mice. Ibuprofen increased the soluble protein content of the muscle without affecting muscle levels of phosphorylated p70 S6 kinase, a ribosomal kinase involved in protein synthesis. Paradoxically, indomethacin increased levels of ubiquitin‐conjugated proteins. Further study is needed to understand the mechanism of action by which indomethacin and ibuprofen preserve body weight and muscle mass in the tumor‐bearing mice. The data suggest that ibuprofen may have beneficial effects in the treatment of cancer cachexia. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:174–184, 2004
Using tissue adjacent to carcinoma as a normal control: an obvious but questionable practice
Authors: Braakhuis Boudewijn JM , Leemans C René , Brakenhoff Ruud H
Published: May 2004

When carcinoma tissue is investigated using biochemical, immunohistochemical, and genetic techniques, adjacent tissue that is macroscopically normal is frequently used as a control, since cancer‐related pheno‐ and geno‐typic alterations are assumed to be absent. However, a field that contains genetically abnormal cells surrounds a significant proportion of carcinomas (for example, over 30% of head and neck cancers). These fields can be large (>7 cm in diameter) and consist of cells that are clonally related to the carcinoma. This indicates that adjacent epithelium must be checked for genetic abnormalities before it is considered normal and used as a control for comparison with carcinoma. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Expression of luminal and basal cytokeratins in human breast carcinoma
Authors: Abd El‐Rehim Dalia M , Pinder Sarah E , Paish Claire E , Bell J , Blamey RW , Robertson John FR , Nicholson Robert I , Ellis Ian O
Published: May 2004

We have examined basal and luminal cell cytokeratin expression in 1944 cases of invasive breast carcinoma, using tissue microarray (TMA) technology, to determine the frequency of expression of each cytokeratin subtype, their relationships and prognostic relevance, if any. Expression was determined by immunocytochemistry staining using antibodies to the luminal cytokeratins (CKs) 7/8, 18 and 19 and the basal markers CK 5/6 and CK 14. Additionally, assessment of α‐smooth muscle actin (SMA) and oestrogen receptor status (ER) was performed. The vast majority of the cases showed positivity for CK 7/8, 18 and 19 indicating a differentiated glandular phenotype, a finding associated with good prognosis, ER positivity and older patient age. In contrast, basal marker expression was significantly related to poor prognosis, ER negativity and younger patient age. Multivariate analysis showed that CK 5/6 was an independent indicator for relapse free interval. We were able to subgroup the cases into four distinct phenotype categories (pure luminal, mixed luminal/basal, pure basal and null), which had significant differences in relation to the biological features and the clinical course of the disease. Tumours classified as expressing a basal phenotype (the combined luminal plus basal and the pure basal) were in a poor prognostic subgroup, typically ER negative in most cases. These findings provide further evidence that breast cancer has distinct differentiation subclasses that have both biological and clinical relevance. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Triazine reaction of cyanate ester resin systems catalyzed by organic tin compound: kinetics and mechanism
Authors: Li Wenfeng , Liang Guozheng , Xin Wenli
Published: May 2004

The mechanism and kinetics of the thermal cure reaction of two cyanate esters (CEs), 1,1′bis(4‐cyanatophenyl)ethane (AroCy L‐10) and bisphenol A dicyanate ester (BADCy), in the presence of dibutyl tin dilaurate (DBTDL) has been investigated using Fourier‐transform infrared spectroscopy (FTIR) and High‐performance liquid chromatography (HPLC). It was found that the organic tin compound (H9C4)2Sn(NCO—R—OCN)2, an active catalyst, has high catalytic efficiency in the polymerization of cyanate esters. The consuming rate of cyanate concentration showed a first‐order dependence on both active catalyst and the cyanate ester monomer concentration. The apparent activation energies (Ea) and frequency factors of both AroCy L‐10 and BADCy were calculated. A mechanism of cyclotrimerization was proposed, based on the kinetic data and FTIR spectra, which involves the formation of an active catalyst and the catalysis of the active catalyst. Copyright © 2004 Society of Chemical Industry
Selected properties of pH‐sensitive, biodegradable chitosan–poly(vinyl alcohol) hydrogel
Authors: Wang Tao , Turhan Mahir , Gunasekaran Sundaram
Published: May 2004

Chitosan and poly(vinyl alcohol) (PVA) were used to form a semi‐interpenetrating polymeric network with glutaraldehyde as the cross‐linker. The molecular weight and degree of deacetylation of the chitosan were 612 kDa and 72 %, respectively. The chemical bonds formed by the cross‐linking reaction and transition of these bonds in different pH media were investigated. The gelation property of the chitosan–PVA pregel solution and mechanical properties of the hydrogel were studied. The FTIR spectra of the hydrogel before and after swelling at pH 3 and pH 7 indicated formation of Schiff's base (CN) and NH3+. They also showed pH‐induced transition of CN to CN, and NH3+ to NH2, as well as the instability of the Schiff's base. The chitosan is essential for hydrogel formation through Schiff's base reaction between the amino groups of the chitosan and the aldehyde groups of the glutaraldehyde. The addition of PVA improved the mechanical properties of the hydrogel. However, PVA tends to leach out at longer swelling times in the acidic medium due to hydrolysis of the gel networks, Schiff's base. Copyright © 2004 Society of Chemical Industry
Contribution of interferometry in evaluating structural parameters for drawn textile fibres
Authors: Shabana HM
Published: May 2004

Two‐beam and multiple‐beam interferometric techniques were used to determine the refractive indices, birefringence and isotropic refractive index of nylon 6 and polyethylene fibres drawn to different draw ratios. These optical parameters contributed in solving the density problem of the drawn fibres in terms of the density of the undrawn fibre. Related parameters such as, crystallinity, number of monomer units per unit volume, polarizability of monomer unit, molar refractivity and certain other parameters were then calculated. In addition, mechanical parameters, such as shrinkage stress, strain and stress optical coefficients, were also calculated. Moreover, the optical orientation function and orientation angle were evaluated. Microinterferograms and relationships between the parameters obtained are given for illustration. Copyright © 2004 Society of Chemical Industry
Aggregate formation and release behaviour of hydrophobic drugs with graft copolypeptide‐containing tryptophan
Authors: Sugimoto Hideki , Nakanishi Eiji , Hanai Takayoshi , Yasumura Takashi , Inomata Katsuhiro
Published: May 2004

In this study, amphiphilic graft copolypeptides containing L‐tryptophan (Trp) were prepared by aminolysis reaction of poly(γ‐benzyl L‐glutamate)‐graft‐poly(Trp) with 2‐amino‐1‐ethanol and then treated with trifluoroacetic acid (TFA). Graft copolypeptide hydrogel membranes treated with TFA were also obtained by same method as the graft copolypeptide in the presence of crosslinking agent. By using these graft copolypeptides and hydrogel membranes, aggregation behaviour and sustained‐release of hydrophobic substance were investigated. In aqueous medium, graft copolypeptides formed aggregates 90 nm in diameter and exhibited the ability to uptake hydrophobic substances into their hydrophobic moiety. TFA‐treated graft copolypeptide showed a pH response; the diameter and uptake ability of the graft copolypeptide were decreased below pH 2.0. This pH response is due to the dissociation of the indole ring of Trp treated with TFA in this pH region. The pH response of drug release from hydrogel membrane treated with TFA was also observed. The hydrophobic drug, testosterone, was released continuously at pH 2.0, whereas the release of testosterone was depressed at pH 5.0. These results can be explained by aggregation and dissociation of Trp residues in the graft copolypeptide. Copyright © 2004 Society of Chemical Industry
Thermal degradation and morphological studies on cotton cellulose modified with various arylphosphorodichloridites
Authors: Dahiya JB , Rana Sushila
Published: May 2004

Cellulose arylphosphonate compounds have been synthesized and investigated by the kinetics of thermal degradation by thermogravimetry (TG) and differential scanning calorimetry (DSC) from ambient temperature to 600°C. Various kinetic and thermodynamic parameters such as energy, entropy and free energy of activation have been obtained from TG curves using the Broido method and transition state theory. The high values of enthalpy change (1016 and 1025 J g−1) of decomposition and oxidation reactions corresponding to the last two exotherms of the DSC curves of cellulose are decreased to a greater extent in the case of cellulose arylphosphonate compounds. The values of activation energy for the decomposition stage of cellulose arylphosphonate compounds lie in the range 25–49 kJ mol−1 and are found to be lower than that of pure cellulose, namely 165 kJ mol−1 in air atmosphere. Scanning electron micrographs of phosphorylated cotton cellulose and chars show furrowed and fractured surfaces although the morphology of the original fibres remains largely unchanged. Furthermore, higher char yields of cellulose derivatives leads to the conclusion that such derivitisation may give rise to flame‐retardant treatments for cellulosic materials. Copyright © 2004 Society of Chemical Industry
Protein expression profiling identifies molecular targets of quercetin as a major dietary flavonoid in human colon cancer cells
Authors: Wenzel Uwe , Herzog Angelika , Kuntz Sabine , Daniel Hannelore
Published: May 2004

A high dietary intake of plant foods is thought to contribute to the prevention of colorectal cancers in humans and flavonoids as part of such a diet are considered to contribute to those protective effects. Quercetin is a major dietary flavonoid consumed with a diet rich in onions, tea, and apples. We used HT‐29 human colon cancer cells and investigated the effects of quercetin on proliferation, apoptosis, and differentiation as processes shown to be disregulated during cancer development. To identify the cellular targets of quercetin action, two‐dimensional gel electrophoresis was performed and proteins altered in expression level after quercetin exposure of cells were identified by mass spectrometry of peptide fragments generated by tryptic digestion. Quercetin inhibited the proliferation of HT‐29 cells with an IC50‐value of 81.2 ± 6.6 μM. Cell differentiation based on surface expression of alkaline phosphatase was enhanced 4‐fold and the activity of the pro‐apoptotic effector caspase‐3 increased 3‐fold. Those effects were associated with the regulation of heat‐shock proteins and annexins shown to both play a crucial role in the process of apoptosis. Cytoskeletal caspase substrates were found as regulated as well and various proteins involved in intermediary metabolism and in gene regulation showed altered steady‐state expression levels upon quercetin treatment of cells. In conclusion, quercetin alters the levels of a variety of proteins involved in growth, differentiation, and apoptosis of colon cancer cells. Their identification as molecular targets of quercetin may explain the anti‐cancer activities of this flavonoid.
Differential protein expression in MCF7 breast cancer cells transfected with ErbB2, neomycin resistance and luciferase plus yellow fluorescent protein
Authors: Wang Daojing , Jensen Ronald H. , Williams Katherine E. , Pallavicini Maria G.
Published: May 2004

Gene transfection is frequently used to explore the molecular and phenotypic consequences of introduced genes. Breast cancer cell lines transfected with genes for growth factor receptors, intracellular signaling molecules or genes that generate luminescent signals are widely used in basic science and preclinical studies. Typically, a target gene of interest is co‐transfected with selectable markers that are generally assumed to be innocuous. Perturbations of the cellular genome by transfected sequences may induce subtle and/or unexpected modulations in protein expression, only some of which may be attributable to the target gene of interest. In this study, we show that neomycin resistant MCF7 cells (MCF7 Neor) proliferate twice as rapidly in nude mice as do the untransfected parent cells, but show similar growth rates in vitro. MCF7 transfected with the ErbB2 gene shows minimal alteration in growth rate in vitro, and approximately a threefold increased growth rate in vivo. MCF7 cells that express luciferase and yellow fluorescent protein proliferate slowly in vitro and show essentially no growth in vivo suggesting that overexpression of these tracking proteins adversely affects cellular proliferative capacity. The molecular basis for alterations in proliferative capacity of the transfected sub‐lines is poorly understood. We performed two‐dimensional gel electrophoresis (2‐DE) to compare relative protein expression among the cell lines. Relative to the parental MCF7, transfected cell lines displayed numerous differentially expressed proteins (69 to 149), relative to parental MCF7. Twenty‐one of these differentially expressed proteins were identified by mass spectrometry, and included metabolic, structural, and signaling proteins. Possible roles of differentially expressed proteins in altering cellular proliferation are discussed.
Proteomics characterization of different bran proteins between aromatic and nonaromatic rice (Oryza sativa L. ssp. indica)
Authors: Trisiriroj Arunee , Jeyachok Narumon , Chen Shui‐Tein
Published: May 2004

Proteomic approach is applied for the analysis of seed brans of 14 rice varieties (Oryza sativa L. ssp. indica) which can classify to five aromatic rice and nine nonaromatic rice. The two‐dimensional electrophoresis (2‐DE) protein patterns for 14 rice varieties were similar within pH ranges of 3–10 and 4–7. To characterize aromatic group‐specific proteins, we compared 2‐D gels of aromatic rice to nonaromatic rice using PDQUEST image analysis. Four out of six differential spots were identified as hypothetical proteins, but one (SSP 7003) was identified by matrix assisted laser desoption/ionization‐quardrupole‐time of fight (MALDI‐Q‐TOF) as prolamin with three matching peptides based on NCBI database. Prolamin is a class of storage proteins with three different polypeptides of 10, 13, and 16 kDa. Spot SSP7003 was identified as a 13 kDa polypeptide of prolamin by combination of mass spectroscopy and N‐terminal sequence analyses. In contrast, one sulfur‐rich 16 kDa polypeptide of prolamin was found in extremely high intensity in brans of deep‐water rice compared to nondeep‐water rice. Our results suggest that proteomics is a powerful step to open the way for the identification of rice varieties.
Proteome analysis of gentisate‐induced response in Pseudomonas alcaligenes NCIB 9867
Authors: Zhao Bing , Yeo Chew Chieng , Lee Chee Chow , Geng Anli , Chew Fook Tim , Poh Chit Laa
Published: May 2004

Pseudomonas alcaligenes NCIB 9867 (P25X wild‐type) is capable of degrading aromatic hydrocarbons via the gentisate pathway. Biochemical characterization of P25X mutants indicated that it has isofunctional enzymes for the mono‐ and dioxygenase‐catalyzed reactions. One set of the enzymes is constitutive whereas the other is strictly inducible. To date, only the gene encoding the constitutively‐expressed gentisate dioxygenase had been cloned and characterized. A mutant strain of P25X, designated G56, which had the constitutive copy of the gentisate 1,2‐dioxygenase gene interrupted by a streptomycin/spectinomycin resistance gene cassette, was found to express gentisate dioxygenase, but only when the cells were induced by gentisate. The proteome profiles of P. alcaligenes P25X and mutant G56 cells grown in the presence and absence of gentisate were compared after two‐dimensional polyacrylamide gel electrophoresis. Eight distinctive protein spots (designated M1–M8) which were observed only in induced cells of strain G56 but absent in noninduced cells were further analyzed by matrix‐assisted laser desorption/ionization‐time of flight, quadrupole‐TOF and N‐terminal sequencing. Of the 15 proteins (including seven up‐regulated) examined, 13 showed sequence similarities to proteins with assigned functions in other microorganisms. The identification of protein M5 which showed high homology to a gentisate dioxygenase from Ralstonia sp. U2 indicated the putative function of this protein being consistent with the inducible gentisate 1,2‐dioxygenase in P. alcaligenes. In addition, the induction of stress proteins and other adaptation phenomena were also observed.
Increases in leukocyte cluster of differentiation antigen expression during cardiopulmonary bypass in patients undergoing heart transplantation
Authors: Lal Sean , Lui Rodney , Nguyen Lisa , Macdonald Peter , Denyer Gareth , dos Remedios Cristobal
Published: May 2004

Cardiopulmonary bypass (CPB) is essential in heart transplantation surgery. It is also used in coronary artery grafting surgery where it has been associated with a postoperative inflammatory response. This manifests as an increase in pro‐inflammatory proteins like interleukin‐8 and tumour necrosis factor α accompanied by increases in neutrophil populations and increased expression of cluster of differentiation (CD) antigens. The latter have been investigated using flow cytometry, which is limited to the measurement of three to four CD antigens simultaneously. We have developed a novel antibody array that can simultaneously measure the expression of 72 different CD antigens. The purpose of this study was to use this technology to measure CD antigen expression in patients undergoing CPB during heart transplantation. Twelve patients undergoing this operation were studied. A preoperative sample acted as an internal control while a second sample taken during CPB was the comparator. No previous studies have examined changes in CD antigen expression during heart transplantation. We report an increase in the expression of 10 different CD antigens across all patients between the two time points.
Prediction of post‐translational glycosylation and phosphorylation of proteins from the amino acid sequence
Authors: Blom Nikolaj , Sicheritz‐Pontén Thomas , Gupta Ramneek , Gammeltoft Steen , Brunak Søren
Published: May 2004

Post‐translational modifications (PTMs) occur on almost all proteins analyzed to date. The function of a modified protein is often strongly affected by these modifications and therefore increased knowledge about the potential PTMs of a target protein may increase our understanding of the molecular processes in which it takes part. High‐throughput methods for the identification of PTMs are being developed, in particular within the fields of proteomics and mass spectrometry. However, these methods are still in their early stages, and it is indeed advantageous to cut down on the number of experimental steps by integrating computational approaches into the validation procedures. Many advanced methods for the prediction of PTMs exist and many are made publicly available. We describe our experiences with the development of prediction methods for phosphorylation and glycosylation sites and the development of PTM‐specific databases. In addition, we discuss novel ideas for PTM visualization (exemplified by kinase landscapes) and improvements for prediction specificity (by using ESS – evolutionary stable sites). As an example, we present a new method for kinase‐specific prediction of phosphorylation sites, NetPhosK, which extends our earlier and more general tool, NetPhos. The new server, NetPhosK, is made publicly available at the URL http://www.cbs.dtu.dk/services/NetPhosK/. The issues of underestimation, over‐prediction and strategies for improving prediction specificity are also discussed.
PhosphoSite: A bioinformatics resource dedicated to physiological protein phosphorylation
Authors: Hornbeck Peter V. , Chabra Indy , Kornhauser Jon M. , Skrzypek Elzbieta , Zhang Bin
Published: May 2004

PhosphoSite™ is a curated, web‐based bioinformatics resource dedicated to physiologic sites of protein phosphorylation in human and mouse. PhosphoSite is populated with information derived from published literature as well as high‐throughput discovery programs. PhosphoSite provides information about the phosphorylated residue and its surrounding sequence, orthologous sites in other species, location of the site within known domains and motifs, and relevant literature references. Links are also provided to a number of external resources for protein sequences, structure, post‐translational modifications and signaling pathways, as well as sources of phospho‐specific antibodies and probes. As the amount of information in the underlying knowledgebase expands, users will be able to systematically search for the kinases, phosphatases, ligands, treatments, and receptors that have been shown to regulate the phosphorylation status of the sites, and pathways in which the phosphorylation sites function. As it develops into a comprehensive resource of known in vivo phosphorylation sites, we expect that PhosphoSite will be a valuable tool for researchers seeking to understand the role of intracellular signaling pathways in a wide variety of biological processes.
ProteoMod: A new tool to quantitate protein post‐translational modifications
Authors: Kumar Yadunanda , Khachane Amit , Belwal Mukta , Das Sanjeev , Somsundaram Kumar , Tatu Utpal
Published: May 2004

Post‐translational modifications (PTMs) are known to regulate biological processes by controlling protein function. The effect of a PTM on protein function depends critically on the position and the number of modifications. While there are convenient methods available to qualitatively examine modifications like phosphorylation, glycosylation, acetylation and methylation, methods available for their quantitative assessment are cumbersome. We have developed a new tool that allows quantitation of the number of phosphorylation events in proteins with ease. The “ProteoMod” tool depends on shifts in the isoelectric points of proteins upon post‐translational change. The extent of shift exhibited upon phosphorylation is algorithmically converted into the number of phosphorylations conferred. The validity of ProteoMod was confirmed by examining proteins with previously known number of phosphorylations. The list of proteins examined included HSP27, HSP70 and tumor suppressor p53. The approach can also be applied to estimate modifications like acetylation, methylation and sialylation in proteins. We analyzed shifts in isoelectric points due to sialylation events in N‐glycoproteins. Using influenza hemagglutinin we show that shifts in isoelectric points correlate with intracellular distribution of this model membrane protein. In addition to extending the application of two dimensional gel electrophoresis to quantitate modifications, our study also highlights its potential use in cell biology.
Development of a mass fingerprinting tool for automated interpretation of oligosaccharide fragmentation data
Authors: Joshi Hiren J. , Harrison Mathew J. , Schulz Benjamin L. , Cooper Catherine A. , Packer Nicolle H. , Karlsson Niclas G.
Published: May 2004

The bioinformatic tool GlycosidIQ™ was developed for computerized interpretation of oligosaccharide mass spectrometric fragmentation based on matching experimental data with theoretically fragmented oligosaccharides generated from the database GlycoSuiteDB™. This use of the software for glycofragment mass fingerprinting obviates a large part of the manual, labor intensive, and technically challenging interpretation of oligosaccharide fragmentation. Using 130 negative ion electrospray ionization‐tandem mass spectrometry fragment spectra from identified oligosaccharide structures, it was shown that the GlycosidIQ scoring algorithms were able to correctly identify oligosaccharides in the great majority of cases (correct structure top ranked in 78% of the cases and an additional 17% were ranked second highest in the sample set).
Sulfonated poly(aryl ether ketone)s containing naphthalene moieties obtained by direct copolymerization as novel polymers for proton exchange membranes
Authors: Xing Peixiang , Robertson Gilles P. , Guiver Michael D. , Mikhailenko Serguei D. , Kaliaguine Serge
Published: May 2004

A series of sulfonated poly(aryl ether ketone)s (SPAEKs) were prepared by aromatic nucleophilic polycondensation of 2,6‐dihydroxynaphthalene with 5,5′‐carbonyl‐bis(2‐fluorobenzenesulfonate) and 4,4′‐difluorobenzophenone. The structure and degree of sulfonation (DS) of the SPAEKs were characterized using 1H NMR spectroscopy. The experimentally observed DS values were close to the expected values derived from the starting material ratios. The thermal stabilities of the SPAEKs were characterized by thermogravimetric analysis, which showed that in acid and sodium salt forms they were thermally stable in air up to about 240 and 380 °C, respectively. Transparent membranes cast from the directly polymerized SPAEKs exhibited good mechanical properties in both dry and hydrated states. The dependence of water uptake and of membrane swelling on the DS at different temperatures was studied. SPAEK membranes with a DS from 0.72 to 1.60 maintained adequate mechanical properties after immersion in water at 80 °C for 24 h. The proton conductivity of SPAEK membranes with different degrees of sulfonation was measured as a function of temperature. The proton conductivity of the SPAEK films increased with increased DS, and the highest room temperature conductivity (4.2 × 10−2 S/cm) was recorded for a SPAEK membrane with a DS of 1.60, which further increased to 1.1 × 10−1 S/cm at 80 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2866–2876, 2004