bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo assessment of myocardial blood flow in rat heart using magnetic resonance imaging: Effect of anesthesia
Authors: Iltis Isabelle , Kober Frank , Dalmasso Christiane , Lan Carole , Cozzone Patrick J. , Bernard Monique
Published: July 2005

Purpose

To assess the influence of isoflurane and pentobarbital anesthesia and the carrier gases on myocardial blood flow (MBF) in the rat heart in vivo.

Materials and Methods

MBF was quantified in vivo using arterial spin‐labeling (ASL) magnetic resonance imaging (MRI). Left ventricular (LV) function was estimated during the same experiment using cine‐MRI. Thirty‐four male Wistar‐Kyoto rats were divided in four groups, one anesthetized with isoflurane in oxygen:nitrous oxide mix (ISO), the three others with intraperitoneal pentobarbital, and breathing either room air (PB), oxygen:nitrous oxide (PB + N2O), or oxygen:nitrogen (PB + N2).

Results

MBF was significantly higher in the ISO and PB + N2O groups vs. PB and in ISO vs. PB + N2, with the following respective MBF values: ISO, 5.9 ± 1.1; PB, 4.0 ± 0.8; PB + N2O, 5.1 ± 1.4; and PB + N2, 4.6 ± 0.8 mL/g/minute, mean ± SD. Ejection fractions were reduced by 10% in PB and PB + N2O rats vs. ISO rats. Cardiac output (CO) and index (CI) were 25 to 30% lower in all rats anesthetized with pentobarbital than with isoflurane.

Conclusion

Isoflurane and nitrous oxide induce a higher MBF than pentobarbital. Isoflurane also induces a higher ejection fraction in healthy rats. J. Magn. Reson. Imaging 2005;22:242–247. © 2005 Wiley‐Liss, Inc.
Registration of two‐dimensional cardiac images to preprocedural three‐dimensional images for interventional applications
Authors: Smolíková‐Wachowiak Renata , Wachowiak Mark P. , Fenster Aaron , Drangova Maria
Published: July 2005

Purpose

To evaluate the accuracy and efficiency of rigid‐body registration of two‐dimensional fast cine and real‐time cardiac images to high‐resolution and SNR three‐dimensional preprocedural reference volumes for application during MRI‐guided interventional procedures.

Materials and Methods

Mutual information (MI) and correlation ratio (CR) similarity measures were evaluated. The dependence of registration accuracy and efficiency on different resolution and SNR parameters, and also on cardiac‐phase differences was evaluated in a porcine model. Two‐dimensional images were initially misoriented at distances (d) of 2–10 mm, and rotations of ±5° about all axes. Registration error and computation time were evaluated, and performance was also assessed visually.

Results

The maximum registration error using MI (<2.7 mm and <3.6°) occurred for d = 10 mm, misrotation of ±5°, and relative SNR = 1. The computation time was 15 seconds for MI and 10 seconds for CR.

Conclusion

Registration accuracy was not highly dependent on the relative timing, within the cycle, between the two‐dimensional and three‐dimensional images. Registration using CR was faster than that using MI, although accuracy was marginally higher with MI. J. Magn. Reson. Imaging 2005;22:219–228. © 2005 Wiley‐Liss, Inc.
Partial rescue of the perfusion deficit area by thrombolysis
Authors: Seitz Rüdiger J. , Meisel Stefanie , Moll Marek , Wittsack Hans‐Jörg , Junghans Ulrich , Siebler Mario
Published: July 2005

Purpose

To investigate the evolution of the perfusion deficit area following systemic thrombolysis with recombinant tissue plasminogen activator (rtPA) in a clinical study on acute cerebral ischemia.

Materials and Methods

We performed volumetric measurements of the acute ischemic lesions in MR images of perfusion (TTP, MTT, and rCBV) and in diffusion‐weighted (DW) images, as well as the manifest stroke lesions in T2‐weighted MR images on day 8. We compared the data of 29 patients who were subjected to systemic thrombolysis with those of 18 patients who were not eligible for thrombolysis.

Results

In the treated patients there were prominent MTT/DWI and TTP/DWI mismatches (P < 0.0006). The acute TTP volumes were smaller than the acute MTT volumes, but as large as the T2 lesions on day 8. The MTT/T2 lesion volume reduction was significant (P < 0.03) in patients who received the GPIIb/IIIa receptor antagonist tirofiban (N = 13) in addition to the low‐dose rtPA. This corresponded to a greater neurological improvement compared to patients who received rtPA alone (P < 0.05). In contrast, in the nontreated patients the initial MTT and TTP lesion volumes were of similar magnitude and predicted the T2 lesions on day 8. In the treated and nontreated patients the TTP lesion signified the viability threshold of acute ischemia, which corresponded to a rCBF of 25 ± 11 mL/100 g/min.

Conclusion

The perfusion deficit area comprises the ischemic core that is destined to undergo necrosis, and an ischemic rim that is salvageable by systemic thrombolysis. J. Magn. Reson. Imaging 2005;22:199–205. © 2005 Wiley‐Liss, Inc.
Spiral coronary angiography using a blood pool agent
Authors: Ringgaard Steffen , Pedersen Michael , Rickers Jonas , Johansson Lars O. , Börnert Peter , Pedersen Erik M.
Published: July 2005

Purpose

To experimentally investigate the optimum dose of an iron‐oxide‐based blood pool agent for spiral coronary MR angiography (MRA), and the difference between single and multiple spiral excitations in each cardiac cycle.

Materials and Methods

Images using single and triple spiral excitations in each cardiac cycle were obtained in late diastole of the left main coronary artery in eight pigs following an inversion prepulse. Measurements were obtained before and after injection of increasing doses of an iron oxide blood pool agent (Clariscan) corresponding to concentrations of 0.8, 2.2, and 3.9 mg Fe/kg BW. The signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) were measured.

Results

For 0.8 mg Fe/kg BW relative to precontrast values, a significant increase was observed for both one (SNR: 2.3, CNR: 3.8) and three (SNR: 1.4, CNR: 2.2) excitations (P < 0.01). When the dose was increased from 0.8 mg Fe/kg BW to 2.2 mg Fe/kg BW, only the SNR (P < 0.01) increased further. Significantly higher CNR (1.6–1.8) and SNR (1.4–1.6) values were seen for one excitation relative to three excitations at all concentrations (P < 0.05).

Conclusion

At low concentrations, an iron oxide blood pool agent can increase SNR and CNR significantly with both single excitation and triple excitations using an inversion‐prepared spiral acquisition scheme. At higher concentrations, T2* effects reduce image quality. J. Magn. Reson. Imaging 2005;22:213–218. © 2005 Wiley‐Liss, Inc.
Left ventricular diastolic function compared with T2* cardiovascular magnetic resonance for early detection of myocardial iron overload in thalassemia major
Authors: Westwood Mark A. , Wonke Beatrix , Maceira Alicia M. , Prescott Emma , Walker J. Malcolm , Porter John B. , Pennell Dudley J.
Published: July 2005

Purpose

To compare left ventricular (LV) diastolic function with myocardial iron levels in beta thalassemia major (TM) patients, using cardiovascular magnetic resonance (CMR).

Materials and Methods

We studied 67 regularly transfused patients with TM and 22 controls matched for age, gender, and body surface area. The early peak filling rate (EPFR) and atrial peak filling rate (APFR) were determined from high‐temporal‐resolution ventricular volume‐time curves. Myocardial iron estimation was achieved using myocardial T2* measurements.

Results

Myocardial iron loading was found in 46 TM patients (69%), in whom the EPFR correlated poorly with T2* (r = −0.20, P = 0.19). The APFR (r = 0.49, P < 0.001) and EPFR/APFR ratio (r = −0.62, P < 0.001) correlated better with T2*. The sensitivity of the diastolic parameters for detecting myocardial iron loading ranged from 4% (EPFR and APFR) to 17% (EPFR/APFR ratio).

Conclusion

Myocardial iron overload results in diastolic myocardial dysfunction, but low sensitivity limits the use of a single estimation for early detection of iron overload, for which T2* has a superior categorical limit of normality. J. Magn. Reson. Imaging 2005;22:229–233. © 2005 Wiley‐Liss, Inc.
Evaluation of in‐stent stenosis by magnetic resonance phase‐velocity mapping in nickel‐titanium stents
Authors: Holton Andrea D. , Walsh Edward G. , Brott Brigitta C. , Venugopalan Ramakrishna , Hershey Bradley , Ito Yasushi , Shih Alan , Koomullil Roy , Anayiotos Andreas S.
Published: July 2005

Purpose

To evaluate different grades of in‐stent stenosis in a nickel‐titanium stent with MRI.

Materials and Methods

Magnetic resonance phase velocity mapping (MR‐PVM) was used to measure flow velocity through a 9‐mm NiTi stent with three different degrees of stenosis in a phantom study. The tested stenotic geometries were 1) axisymmetric 75%, 2) axisymmetric 90%, and 3) asymmetric 50%. The MR‐PVM data were subsequently compared with the velocities from computational fluid dynamic (CFD) simulations of identical conditions.

Results

Good quantitative agreement in velocity distribution for the 50% and 75% stenoses was observed. The agreement was poor for the 90% stenosis, most likely due to turbulence and the high‐velocity gradients found in the small luminal area relative to the pixel resolution in our imaging settings.

Conclusion

The accuracy of the MRI velocities inside the stented area renders MRI a modality that may be used to assess moderate to severe in‐stent restenosis (ISR) in medium‐sized vascular stents in peripheral vessels, such as the iliac, carotid, and femoral arteries. Advances in MR instrumentation may provide sufficient resolution to obtain adequate velocity information from smaller vessels, such as the coronary arteries, and allow MRI to substitute for invasive and expensive catheterization procedures currently in clinical use. J. Magn. Reson. Imaging 2005;22:248–257. © 2005 Wiley‐Liss, Inc.
Arylsulfonates as sole source of sulfur for Clostridium pasteurianum DSM 12136
Authors: Chien Chih‐Ching
Published: July 2005

A variety of arylsulfonates were examined for their ability to support growth of Clostridium pasteurianum as sole source of sulfur. Among the eleven different arylsulfonates tested, six of them (benzenesulfonate, 4‐toluenesulfonate, 4‐xylene‐2‐sulfonate, 4‐aminobenzenesulfonate, 4‐sulfobenzoic acid, 1,3‐benzenedisulfonate) could serve as sole sulfur source for C. pasteurianum DSM 12136. None of the sulfonates tested could serve as sole sulfur source for C. pasteurianum ATCC 6013. The two C. pasteurianum in this study could not utilize any of these sulfonates as sole carbon and energy source. We demonstrated that desulfonation of arylsulfonates could take place under anoxic conditions and the sulfur atom of these compounds could be utilized as sole source of sulfur by anaerobic bacteria. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of bacteriocins produced by lactic acid bacteria isolated from spoiled black olives
Authors: Todorov Svetoslav D. , Dicks Leon M. T.
Published: July 2005

Bacteriocin‐producing strains of Lactobacillus plantarum ST23LD and ST341LD, Enterococcus faecium ST311LD and Leuconostoc mesenteroides subsp. mesenteroides ST33LD were isolated from the brine of spoiled black olives. The bacteriocins produced by all four strains inhibited the growth of Gram‐positive bacteria (E. faecalis, L. casei and Streptococcus pneumoniae), but also Escherichia coli and Pseudomonas aeruginosa. Strain ST23LD produced two bacteriocins (ST23LDa and ST23LDb of approximately 3.0 and 14.0 kDa, respectively), with a combined maximum level of activity of 25600 AU/ml after 18 h of growth. The same level of activity was recorded for bacteriocin ST341LD (approximately 3.0 kDa), but after 16 h. Bacteriocins ST311LD (ca. 2.3 kDa) and ST33LD (ca. 2.7 kDa) were produced at much lower levels (6400 AU/ml), and only after 20 h of growth. Bacteriocin activity was destroyed after treatment with proteolytic enzymes and Triton X, but not when treated with α‐amylase, SDS, Tween 20, Tween 80, urea and EDTA, or when heated for 20 min at 121 °C. Addition of bacteriocins ST23LD, ST341LD and ST311LD to cells of Lactobacillus casei LHS in logarithmic phase resulted in growth inhibition for one hour, followed by a slight increase in optical density over the next seven hours. Bacteriocin ST33LD also inhibited the growth of strain LHS, but to a lesser extent. Bacteriocins ST23LD, ST341LD and ST33LD remained at the same level of activity for 6 h at pH < 4.0. However, the activity of bacteriocin ST311LD decreased by 50% within 2 h at pH 4.4. The possibility of the bacteriocin adsorbing to the producer cell and proteolytic degradation is unlikely. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Annual trace element cycles in calcite–aragonite speleothems: evidence of drought in the western Mediterranean 1200–1100 yr BP
Authors: McMillan Emily A. , Fairchild Ian J. , Frisia Silvia , Borsato Andrea , McDermott Frank
Published: July 2005

Each of two calcitic stalagmites from Grotte de Clamouse, Herault, southern France, displays a discrete aragonite layer dated at around 1100 yr BP. The layer of fanning aragonite ray crystals is immediately preceded by calcite with Mg and Sr compositions that are uniquely high for the past 3 kyr. Trace element compositions close to the boundary between original aragonite and calcite are consistent with quasi‐equilibrium partitioning of trace elements between the phases. Study of modern dripwaters demonstrates that pronounced covariation of Mg/Ca and Sr/Ca ratios in dripwater occurs owing to large amounts of calcite precipitation upflow of the drips that fed the stalagmites. Trace element to Ca ratios are enhanced during seasonally dry periods. Ion microprobe data demonstrate a pronounced covariation of trace elements, including Mg and Sr in calcite, and Sr, U and Ba in aragonite. The mean peak spacing is close to the long‐term mean of annual growth rates determined by differences in U‐series ages and so the trace element peaks are interpreted as annual. The trace element chemistry of the stalagmites on annual to inter‐annual scales thus directly reflects the amounts of prior calcite precipitation, interpreted as an index of aridity. The longer‐term context is a multi‐decadal period of aridity (1200–1100 yr BP) possibly correlated with an analogous episode in Central America. The arid period culminated in the nucleation of aragonite, but within a decade was followed by a return to precursor conditions. Copyright © 2005 John Wiley & Sons, Ltd.
Late Quaternary climate change record from two long sediment cores from Guaymas Basin, Gulf of California
Authors: Cheshire Heather , Thurow Jürgen , Nederbragt Alexandra J.
Published: July 2005

Modern Guaymas Basin (Gulf of California, Mexico) is a region of high diatom productivity where exceptional preservation factors maintain biannually alternating sediment deposition as annual varves. New sediment cores from Guaymas Basin (MD02‐2512 and MD02‐2515) present the opportunity to construct climate records from below the last glacial period. A low‐resolution age model has been constructed from oxygen isotope analysis, correlation with other dated short piston cores from Guaymas Basin and an estimate of sedimentation rate. MD02‐2512 from eastern Guaymas Basin has an age range from the Holocene to late marine isotope stage 6 (MIS 6); MD02‐2515 from western Guaymas Basin has an age range from ∼8000 to 40 000 yr. Shipboard analyses of colour reflectance, magnetic susceptibility and sediment density are combined with continuous X‐ray fluorescence scans to reconstruct a picture of glacial climate in the Gulf of California. Eastern Guaymas Basin is affected by glacial sea level fall, which results in a drastic change in productivity rates and sediment type. The laminated record of MIS 5 allows comparison with the Holocene, showing a similarity of sedimentation patterns during deglaciation and a series of very rapid variations just prior to the last glaciation. In western Guaymas Basin there are a series of Younger Dryas‐like events during the glacial, typified by low productivity and high terrigenous input. Long‐term climate and productivity changes appear to be caused by the southward displacement of the Subtropical High pressure zone. Copyright © 2005 John Wiley & Sons, Ltd.
Deglacial seasonal and sub‐seasonal diatom record from Palmer Deep, Antarctica
Authors: Maddison Eleanor J. , Pike Jennifer , Leventer Amy , Domack Eugene W.
Published: July 2005

The Antarctic Peninsula is one of the most sensitive regions of Antarctica to climate change. Here, ecological and cryospheric systems respond rapidly to climate fluctuations. A 4.4 m thick laminated diatom ooze deposited during the last deglaciation is examined from a marine sediment core (ODP Site 1098) recovered from Basin I, Palmer Deep, western Antarctic Peninsula. This deglacial laminated interval was deposited directly over a glaciomarine diamict, hence during a globally recognised period of rapid climate change. The ultra‐high‐resolution deglacial record is analysed using SEM backscattered electron imagery and secondary electron imagery. Laminated to thinly bedded orange‐brown diatom ooze (near monogeneric Hyalochaete Chaetoceros spp. resting spores) alternates with blue‐grey terrigenous sediments (open water diatom species). These discrete laminae are interpreted as austral spring and summer signals respectively, with negligible winter deposition. Sub‐seasonal sub‐laminae are observed repeatedly through the summer laminae, suggesting variations in shelf waters throughout the summer. Tidal cycles, high storm intensities and/or intrusion of Circumpolar Deep Water onto the continental shelf introduced conditions which enhanced specific species productivity through the season. Copyright © 2005 John Wiley & Sons, Ltd.
Detection system for electro‐separation analytical methods
Authors: Štohl Radek , Glovinová Eliška , Pospíchal Jan
Published: July 2005

The paper provides information about the on‐line monitoring of components analysed by capillary electrophoresis. For this purposes we developed a whole‐capillary transverse scanning detection system, which helps to improve and control the separation processes. A picture from a colour line scanner was used as a source of basic information for autonomous control of the separation process by regulation of the high voltage source. The application and algorithms for machine vision were designed in the progressive graphic development system LabVIEW. Real‐time control of the separation process was implemented in a compact control process logic controller. The performance of the detection system was evaluated and the function of the overall system was tested by performing isotachophoretic analysis of a model mixture.
Supercritical fluid extraction of isoflavones from biological samples with ultra‐fast high‐performance liquid chromatography/mass spectrometry
Authors: Klejdus Bořivoj , Lojková Lea , Lapčík Oldřich , Koblovská Radka , Moravcová Jitka , Kubáň Vlastimil
Published: July 2005

An efficient method of modifier addition for supercritical fluid extraction (SFE) of polar isoflavones was developed and yielded extraordinarily high recoveries. To find the optimal extraction conditions, a temperature and pressure optimization and modifier impact study was performed in naturally contaminated and spiked samples. Ultra‐fast high‐performance liquid chromatography/mass spectrometry (HPLC/MS) was used for the determination of isoflavones on an AtlantisTM dC18 high‐speed reversed phase chromatographic column (20×2.1 mm, 3 μm particle size). A newly elaborated supercritical fluid extraction (SFE) procedure allowed more accurate (< 5%) and precise (< 4–7%) determination of isoflavones in biological materials. The HPLC/MS method significantly reduced analysis time with simultaneous improvement of sensitivity and detection limits. The on‐column limits of detection LOD (S/N = 3) for isoflavone glycosides (daidzin, genistin, glycitin, ononin, and sissotrin) were 1.3–3.6 fmol and 0.2–1.0 fmol for aglycones (daidzein, glycitein, genistein, formononetin, and biochanin A), respectively.
Enantioselective analysis of cetirizine in pharmaceuticals by cyclodextrin‐mediated capillary electrophoresis
Authors: Mikuš Peter , Valášková Iva , Havránek Emil
Published: July 2005

The present paper demonstrates the potential of cyclodextrin (CD)‐mediated CE for the chiral analysis of a drug of zwitterionic nature, viz. cetirizine (CET). Various separation mechanisms were applied and several parameters affecting the separation were studied, including the type and concentration of chiral selector, coselector, and carrier ion, and pH of buffer. The optimal separation conditions were based on a medium buffer pH (≈5.2) (migration velocity of CET molecule was near to zero) and a highly substituted CD derivative, sulfated‐β‐CD, serving as an analyte carrier in the anionic regime of the separation with suppressed electroosmotic flow. In this way, a baseline enantioseparation, reasonable separation efficiency, and short analysis time could be easily achieved. Acceptable validation criteria for sensitivity, linearity, precision, accuracy, and robustness were obtained using a hydrodynamically closed CE separation system. The proposed method was successfully applied to the enantioselective assay of CET in pharmaceutical formulations using fexofenadine (FEX) as an internal standard.
Simultaneous Ionic and Electronic Conductivity in Polymeric Materials
Authors: Costantini Nicola , Wegner Gerhard , Mierzwa Michal , Pakula Tadeusz
Published: July 2005

Summary: Pyrrole and 3‐(3,6‐dioxaheptyl)pyrrole were polymerized in the presence of an oligo(oxyethylene monomethylether) sulfonate (DPPEO = 17) with ammonium peroxydisulfate as an oxidizing agent and dry chloroform as a solvent. The oligo(oxyethylene) sulfonate acted as a phase transfer agent and also became incorporated into the polymer as a counter ion. The polymers were obtained as gel‐like particles that could be easily dispersed in organic solvent and could be doped with lithium triflate to enhance the ionic conductivity of the electronically conductive materials. DSC and X‐ray measurements showed a glass transition (Tg) in all samples at around −40 °C which is related to the dynamics of the EO segments. In addition, the system composed of polypyrrole with oligo(oxyethylene) sulfonate counter ions showed partial crystallinity and a melting transition at 34 °C. Conductivity was explored by impedance spectroscopy with regard to frequency and temperature dependence. The data could be evaluated in the coordinates of an Arrhenius plot as the sum of two Arrhenius functions in all cases. Although one Arrhenius‐type function was sufficient to describe the temperature profile of the conductivity below Tg, a second term needed to be added at T > Tg. The absolute values of conductivity were also dependent on the level of doping with lithium triflate. These phenomena were interpreted as a contribution of ionic conductivity by the lithium ions to the electronic conductivity, which comes about from the oxidation state of the polypyrrole backbone.

A good Li‐ion conducting polymer which also exhibits electronic conductivity.

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A good Li‐ion conducting polymer which also exhibits electronic conductivity.
Polymethacrylate Copolymers Containing 4,5‐Dicyanoimidazole‐Based Chromophores and their Nonlinear Optical Behavior
Authors: Carella Antonio , Centore Roberto , Riccio Pierluigi , Sirigu Augusto , Quatela Alessia , Palazzesi Christian , Casalboni Mauro
Published: July 2005

Summary: Two series of methacrylate copolymers were prepared, based on two new nonlinear optically (NLO) active chromophores 2‐[4‐(N‐methacryloyloxyethyl‐N‐methylamino)phenylazo]‐4,5‐dicyanoimidazole (chromophore A) and 1‐ethyl‐2‐[4‐(N‐methacryloyloxyethyl‐N‐methylamino)phenylazo]‐4,5‐dicyanoimidazole (chromophore B). Second order NLO properties of the two series of copolymers (A or B as monomer and methyl methacrylate as the comonomer) were investigated by SHG procedures at the fundamental wavelength 1368 nm; d33 values in the range 0.2–3.3 pm · V−1 were obtained, depending on the chromophore and on its molar content. The dependence of d33 on the molar content of chromophore was investigated in the two cases.

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Low‐Rate Propylene Slurry Polymerization: Morphology and Kinetics
Authors: Pimplapure Makarand S. , Zheng Xuejing , Loos Joachim , Weickert Günter
Published: July 2005

Summary: “True” initial polymerization rates can be calculated from the adiabatic temperature rise under isoperibolic conditions. They are much higher than initial polymerization rates measured by standard mass flow meter methods under quasi‐steady‐state conditions. These high initial rates are followed by a fast apparent deactivation (“attenuation”) until a constant (“plateau”) activity is reached at low polymerization yields of 2–3 g PP · (g catalyst)−1 caused by an “increasing degree of encapsulation” of active sites. Mass transfer limitations are not observed. Cross sectional SEM images of the polymer samples support these kinetic findings.

Rate of polymerization (g of PP · (g catalyst)−1 · h−1) and yield of polymerization (g of PP · (g catalyst)−1) as function of time.

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Rate of polymerization (g of PP · (g catalyst)−1 · h−1) and yield of polymerization (g of PP · (g catalyst)−1) as function of time.
Polymer‐Grafted Carbon Spheres by Surface‐Initiated Atom Transfer Radical Polymerization
Authors: Jin Yi Zheng , Gao Chao , Kroto Harold W. , Maekawa Toru
Published: July 2005

Summary: In situ atom transfer radical polymerization techniques have been used to produce polymer‐grafted carbon spheres (CSs). The surfaces of as‐prepared CSs were functionalized in the presence of CS‐supported macroinitiators. The resulting materials were characterized by FTIR and NMR spectroscopy, TGA, SEM, TEM, and HRTEM. The amount of polymer grafted onto the surfaces of the spheres can be controlled by varying the monomer/initiator feed ratio. The wetting ability and dispersibility of the polymer‐grafted CSs were improved significantly, compared with crude CSs, enabling stable dispersions in organic solvents to be produced. SEM and TEM studies indicate that a uniform distribution of the carbon spheres in the continuous polymer phase can be produced.

SEM image (left) of poly(glycerol monomethacrylate) grafted carbon spheres, inset shows the structure. HRTEM image (right) of a polystyrene grafted carbon sphere, inset is the SAED pattern.

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SEM image (left) of poly(glycerol monomethacrylate) grafted carbon spheres, inset shows the structure. HRTEM image (right) of a polystyrene grafted carbon sphere, inset is the SAED pattern.
Shape of Micelles Formed From Strongly Adsorbed Grafted Polymers in Poor Solvents
Authors: Pattanayek Sudip K. , Pereira Gerald G.
Published: July 2005

Summary: We consider the shape of strongly adsorbed polymer chains in poor solvents. Using both SCF theory and Monte Carlo simulations, we find these chains undergo an instability which is driven, surprisingly, by polymer entropy. This instability occurs above some critical grafting separation and the intermediate segregation regime. An analytical calculation also suggests that this instability occurs for strongly adsorbed polymer chains. We proceed to study multi‐chain systems and observe a number of novel morphological structures including circular polymer droplets, lamellae and a polymer layer with a solvent‐filled hole.

Shape of strongly adsorbed multi‐chain polymer globules.

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Shape of strongly adsorbed multi‐chain polymer globules.
Proxy reports in Parkinson's disease: Caregiver and patient self‐reports of quality of life and physical activity
Authors: Fleming Allison , Cook Karon F. , Nelson Naomi D. , Lai Eugene C.
Published: July 2005

We evaluated patient–proxy agreement in a population of veterans with Parkinson's disease and compared levels of agreement by patient subgroups. Patient and caregiver pairs completed questionnaires composed of standard measures and additional demographic and activity questions. Participants completed the Center for Epidemiologic Studies Depression Scale (CES‐D), the PD Questionnaire 39 (PDQ‐39), and three questions regarding physical activity. Caregivers completed proxy forms of the PDQ‐39 and the physical activity questionnaire. The proxy forms asked caregivers to choose the answers that best described their “friend's/patient's situation.” The results of our comparison of patient and proxy reports of quality of life were consistent with findings in other diseases. On average, proxies rated patient disability higher and quality of life lower than did patients. However, our comparison of patient and proxy reports of frequency of exercise diverged from previously published work. Less agreement was observed between patient and proxy reports of physical activity, even though this is a more objective variable than are the domains measured by the PDQ‐39. Proxy reports may diverge appreciably from patient self‐reports. These differences should be considered in research design and clinical decision making. Alternative approaches to the measurement of patient relevant outcomes could supplement traditional, retrospective self‐reports. © 2005 Movement Disorder Society
Numerical analysis of a model for an axisymmetric guide for electromagnetic waves Part I: the continuous problem and its Fourier expansion
Authors: Belgacem Faker Ben , Bernardi Christine , Rapetti Francesca
Published: July 2005

As a first model for an electromagnetic wave guide, we consider Maxwell's system in a three‐ dimensional axisymmetric domain provided with appropriate boundary conditions on different parts of the boundary. We check the well‐posedness of the corresponding variational problem. We write the Fourier expansion of the solution as a function of the angular variable and derive the well‐posedness of the two‐dimensional problems satisfied by each Fourier coefficient. The first step for approximating the three‐dimensional solution relies on Fourier truncation, and we prove optimal estimates for the error issued from this truncation. Copyright © 2005 John Wiley & Sons, Ltd.
Cobalt(II) octanoate and cobalt(II) perfluorooctanoate catalyzed atom transfer radical polymerization of styrene in toluene and fluorous media—A versatile route to catalyst recycling and oligomer formation
Authors: Weiser Marc‐Stephan , Mülhaupt Rolf
Published: July 2005

Cobalt(II) perfluorooctanoate‐catalyzed atom transfer radical polymerization (ATRP) and reverse ATRP were developed to prepare oligostyrenes (Mn < 2500) with low polydispersities Mw/Mn < 1.5. Fluorous biphase catalysis was applied for effective recycling of catalyst and fluorous solvent. The homogeneous polymerization reaction was performed at 90 °C in toluene/cyclohexane/perfluorodecalin mixture (1:1:1) and fluorine‐free solvents. Temperature‐induced phase separation of this fluorous solvent mixture occurred at room temperature and proved to be the key for the very effective separation of the cobalt(II) perfluorooctanoate from the oligostyrene and fluorine‐free solvents. Both the fluorine‐tagged cobalt catalysts and the fluorous media were recycled and reused up to three times without encountering catalyst activity losses. The roles of cobalt catalysts, fluorous media, and monomer/initiator ratio were examined with respect to the polymerization kinetics. Fluorine‐containing and fluorine‐free cobalt(II) octanoate catalyzed controlled styrene oligomerization according to the ATRP mechanism. The molar mass control range was limited in fluorous biphase catalysis most likely because of precipitation of high molar mass polystyrenes in the fluorous reaction medium. To the best of our knowledge, this is the first time temperature‐induced phase separation of fluorous and fluorine‐free solvents has been successfully applied to polymerization processing. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3804–3813, 2005
Hydrogen‐bond‐assisted stereocontrol in the radical polymerization of N‐isopropylacrylamide with secondary alkyl phosphate: The effect of the bulkiness of the ester group
Authors: Hirano Tomohiro , Kitajima Hiroko , Ishii Satoshi , Seno Makiko , Sato Tsuneyuki
Published: July 2005

The radical polymerization of N‐isopropylacrylamide (NIPAAm) in toluene at low temperatures was investigated in the presence of triisopropyl phosphate (TiPP). The addition of TiPP induced a syndiotactic specificity that was enhanced by the polymerization temperature being lowered, whereas atactic polymers were obtained in the absence of TiPP, regardless of the temperature. Syndiotactic‐rich poly(NIPAAm) with a racemo dyad content of 65% was obtained at −60 °C with a fourfold amount of TiPP, but almost atactic poly(NIPAAm)s were obtained by the temperature being lowered to −80 °C. This result contrasted with the result in the presence of primary alkyl phosphates, such as tri‐n‐propyl phosphate: the stereospecificity varied from syndiotactic to isotactic as the polymerization temperature was lowered. NMR analysis at −80 °C revealed that TiPP predominantly formed a 1:1 complex with NIPAAm, although primary alkyl phosphates preferentially formed a 1:2 complex with NIPAAm. Thus, it was concluded that a slight increase in the bulkiness of the added phosphates influenced the stoichiometry of the NIPAAm–phosphate complex at lower temperatures, and consequently a drastic change in the effect on the stereospecificity of NIPAAm polymerization was observed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3899–3908, 2005
Large LNG fire thermal radiation—modeling issues and hazard criteria revisited
Authors: Raj Phani K.
Published: July 2005

Current models for evaluating the exclusion (hazard) zones around liquefied natural gas (LNG) fires in both U.S. Regulations and NFPA‐59A standard are prescriptive and require the consideration of large LNG releases. These models do not consider the effects of the combustion dynamics associated with large‐size pool burning. Oxygen starvation in the core of LNG fires of diameters ≳ 35 m leads to the formation of nonluminous, cold soot (smoke) resulting in a reduction of thermal energy radiated by the fire to the surroundings. The net effect is smaller (calculated) thermal hazard distances for exposure to people (by factors of 2 or 3 compared to results ignoring this phenomenon). Available large‐scale LNG fire test information is reviewed to quantify the effect of this phenomenon. This paper also discusses the common mistakes made in calculating the thermal radiation hazard distances around large fires by using, for the energy radiated from the fire, a constant percentage of energy generated by combustion. The criteria for setting thermal radiation hazard zones around large hydrocarbon fires are also reviewed. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Monitoring Infrequent Failures of High‐volume Production Processes
Authors: Di Bucchianico A. , Mooiweer G. D. , Moonen E. J. G.
Published: July 2005

We present a case study in monitoring a high‐volume production process with a high yield. Testing the products is difficult and is only possible in a destructive way with a defect/no‐defect result. We review several attribute charting procedures for high‐yield processes. It turns out that monitoring the number of conforming items between the occurrence of non‐conforming items is appropriate. We discuss several implementation aspects of CCCr charts in our case study. The implementation is based on a new formula for the standard deviation of the number of inspected items before a signal. Copyright © 2005 John Wiley & Sons, Ltd.
The Circular Safety Region: a Useful Graphical Tool in Capability Analysis
Authors: Vännman Kerstin
Published: July 2005

When measuring the capability of a manufacturing process some form of process capability index is often used. To assess the capability, using a random sample, confidence intervals or hypothesis tests on the index are frequently used. Here, an alternative approach is presented. A process is usually defined to be capable if the capability index exceeds a stated threshold value, e.g. Cpm > $4\over 3$. This inequality can be expressed graphically as a region in the plane defined by the process parameters (μ, σ). This graphical region, or safety region, similar to a confidence region for (μ, σ), can be plotted to test for capability. Under the assumption of normality a circular safety region for the capability index Cpm is constructed that can be used to draw conclusions about the capability at a given significance level. This simple graphical approach is helpful when trying to understand if it is the variability, the deviation from target or both that need to be reduced to improve the capability. Using circular regions several characteristics can be monitored in the same plot. Copyright © 2005 John Wiley & Sons, Ltd.
Electronic Fock spaces: Phase prefactors and new algebraic structure
Authors: Panin A. I.
Published: July 2005

An efficient technique of manipulation with phase prefactors in electronic Fock spaces is developed. Its power is demonstrated in an example of both relatively simple classic configuration interaction matrix element evaluation and an essentially more complicated coupled cluster case. Interpretation of coupled cluster theory in terms of a certain commutative algebra is given. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Modelling the spread of penicillin‐resistant Streptococcus pneumoniae in day‐care and evaluation of intervention
Authors: Andersson Mikael , Ekdahl Karl , Mölstad Sigvard , Persson Kristina , Hansson Hans Bertil , Giesecke Johan
Published: July 2005

In 1995, a disease control and intervention project was initiated in Malmöhus county in southern Sweden to limit the spread of penicillin‐resistant pneumococci. Since most of the carriers of pneumococci are preschool children, and since most of the spread is believed to take place in day‐care, a mathematical model, in the form of a stochastic process, for the spread in a day‐care group was constructed. Effects of seasonal variation and size of the day‐care group were particularly considered. The model was then used for comparing results from computer simulations without and with intervention. Results indicate that intervention is highly effective in day‐care groups with more than ten children during the second half of the year. Copyright © 2005 John Wiley & Sons, Ltd.
Continuous Bayesian adaptive randomization based on event times with covariates
Authors: Cheung Ying Kuen , Inoue Lurdes Y. T. , Wathen J. Kyle , Thall Peter F.
Published: July 2005

In comparative clinical trials, the randomization probabilities may be unbalanced adaptively by utilizing the interim data available at each patient's entry time to favour the treatment or treatments having comparatively superior outcomes. This is ethically appealing because, on average, more patients are assigned to the more successful treatments. Consequently, physicians are more likely to enrol patients onto trials where the randomization is outcome‐adaptive rather than balanced in the conventional manner. Outcome‐adaptive methods based on a binary variable may be applied by reducing an event time to the indicator of the event's occurrence within a predetermined time interval. This results in a loss of information, however, since it ignores the censoring times of patients who have not experienced the event but whose evaluation interval is not complete. This paper proposes and compares exact and approximate Bayesian outcome‐adaptive randomization procedures based on time‐to‐event outcomes. The procedures account for baseline prognostic covariates, and they may be applied continuously over the course of the trial. We illustrate these methods by application to a phase II selection trial in acute leukaemia. A simulation study in the context of this trial is presented. Copyright © 2005 John Wiley & Sons, Ltd.
Shared parameter models for the joint analysis of longitudinal data and event times
Authors: Vonesh Edward F. , Greene Tom , Schluchter Mark D.
Published: July 2005

Longitudinal studies often gather joint information on time to some event (survival analysis, time to dropout) and serial outcome measures (repeated measures, growth curves). Depending on the purpose of the study, one may wish to estimate and compare serial trends over time while accounting for possibly non‐ignorable dropout or one may wish to investigate any associations that may exist between the event time of interest and various longitudinal trends. In this paper, we consider a class of random‐effects models known as shared parameter models that are particularly useful for jointly analysing such data; namely repeated measurements and event time data. Specific attention will be given to the longitudinal setting where the primary goal is to estimate and compare serial trends over time while adjusting for possible informative censoring due to patient dropout. Parametric and semi‐parametric survival models for event times together with generalized linear or non‐linear mixed‐effects models for repeated measurements are proposed for jointly modelling serial outcome measures and event times. Methods of estimation are based on a generalized non‐linear mixed‐effects model that may be easily implemented using existing software. This approach allows for flexible modelling of both the distribution of event times and of the relationship of the longitudinal response variable to the event time of interest. The model and methods are illustrated using data from a multi‐centre study of the effects of diet and blood pressure control on progression of renal disease, the modification of diet in renal disease study. Copyright © 2005 John Wiley & Sons, Ltd.
Four‐fold table cell frequencies imputation in meta analysis
Authors: Di Pietrantonj Carlo
Published: July 2005

Meta analysis is a collection of quantitative methods devoted to combine summary information from related but independent studies. Because research reports usually present only data reductions and summary statistics rather than detailed data, the reviewer must often resort to rather crude methods for constructing summary effect estimate suitable for meta analysis pooling methods. When the studies involve a binary variable, both number of events and sample sizes are required to compute pooled estimate and its confidence interval. Sometimes, only summary statistics and related confidence intervals are provided in the publication. Although it is possible to estimate the standard error of each study's effect measure using the confidence interval from each study, this lack of detailed data compels the reviewers to use the inverse variance method to perform meta analysis, or to exclude the works with incomplete data. This paper shows three methods to reconstruct four‐fold tables when summary measures for binary data and related confidence intervals and sample sizes are provided. The methods are discussed through a wider application example to assess the reconstruction precision, and the impact of using reconstructed data on meta analysis results. These methods seem to yield a correct reconstruction if original measures are reported at least with two decimal places. Meta analysis results do not seem seriously affected by the use of reconstructed data. These methods allow the reviewer to use full meta analysis statistical tools, instead of the simple inverse variance method, and can greatly contribute to the completeness of systematic reviews. Copyright © 2005 John Wiley & Sons, Ltd.
Diclofenac attenuates Wnt/β‐catenin signaling in colon cancer cells by activation of NF‐κB
Authors: Cho Munju , Gwak Jungsug , Park Seoyoung , Won Jaejoon , Kim Dong-Eun , Yea Sung Su , Cha In-June , Kim Tae Kook , Shin Jae-Gook , Oh Sangtaek
Published: July 2005

The dysregulation of Wnt/β‐catenin signaling and subsequent upregulation of β‐catenin response transcription (CRT) occur frequently in colon cancer cells. Non‐steroidal anti‐inflammatory drugs (NSAIDs) can repress CRT in colorectal cancer, but little is known about the mechanism of action. We show that the NSAID diclofenac inhibits Wnt/β‐catenin signaling without altering the level of β‐catenin protein and reduces the expression of β‐catenin/TCF‐dependent genes. Diclofenac induced the degradation of IκBα, which increased free nuclear factor κB (NF‐κB) in cells. Also, the ectopic expression of p65, which is a component of NF‐κB, suppressed CRT. Our findings suggest that diclofenac inhibits Wnt/β‐catenin signaling via the activation of NF‐κB in colon cancer cells.
OD1, the first toxin isolated from the venom of the scorpion Odonthobuthus doriae active on voltage‐gated Na+ channels
Authors: Jalali Amir , Bosmans Frank , Amininasab Mehriar , Clynen Elke , Cuypers Eva , Zaremirakabadi Abbas , Sarbolouki Mohammad-Nabi , Schoofs Liliane , Vatanpour Hossein , Tytgat Jan
Published: July 2005

In this study, we isolated and pharmacologically characterized the first α‐like toxin from the venom of the scarcely studied Iranian scorpion Odonthobuthus doriae. The toxin was termed OD1 and its primary sequence was determined: GVRDAYIADDKNCVYTCASNGYCNTECTKNGAESGYCQWIGRYGNACWCIKLPDEVPIRIPGKCR. Using the two‐electrode voltage clamp technique, the pharmacological effects of OD1 were studied on three cloned voltage‐gated Na+ channels expressed in Xenopus laevis oocytes (Nav1.2/β1, Nav1.5/β1, para/tipE). The inactivation process of the insect channel, para/tipE, was severely hampered by 200 nM of OD1 (EC50
= 80 ± 14 nM) while Nav1.2/β1 still was not affected at concentrations up to 5 μM. Nav1.5/β1 was influenced at micromolar concentrations.
RNA interference‐mediated silencing of the syntaxin 5 gene induces Golgi fragmentation but capable of transporting vesicles
Authors: Suga Kei , Hattori Hiroshi , Saito Ayako , Akagawa Kimio
Published: July 2005

It has been suggested that syntaxin 5 (Syx5) participates in vesicular transport. We examined the effects of Syx5 down‐regulation on the morphology of the Golgi apparatus and the transport of vesicles in mammalian cells. Knockdown of the Syx5 gene resulted in Golgi fragmentation without changing the level of endoplasmic reticulum (ER)‐resident proteins, other Golgi‐SNAREs (soluble N‐ethylmaleimide‐sensitive factor‐attachment protein receptors), and coatmer proteins. Strikingly, a major decrease in Syx5 expression barely affected the anterograde transport of vesicular stomatitis virus G (VSVG) protein to the plasma membrane. These results suggest that Syx5 is required for the maintenance of the Golgi structures but may not play a major role in the transport of vesicles carrying VSVG between the ER and the Golgi compartment.
Coordinated synthesis of the two ClpB isoforms improves the ability of Escherichia coli to survive thermal stress
Authors: Chow I-Ting , Baneyx François
Published: July 2005

Eubacteria synthesize a full‐length (ClpB95) and a N‐terminally truncated (ClpB80) version of the ClpB disaggregase owing to the presence of a translation initiation site within the clpB transcript. Why these two isoforms have been evolutionary conserved is poorly understood. Here, we constructed a series of E. coli strains and plasmids allowing production of the ClpB95/ClpB80 pair, ClpB95 alone, or ClpB80 alone from near physiological concentrations to a 6–10‐fold excess over normal cellular levels. We found that although overexpressed ClpB95 or ClpB80 can independently restore basal thermotolerance to ΔclpB cells, strains expressing ClpB80 from the clpB chromosomal locus do not exhibit increased resistance to thermal killing at 50 °C relative to clpB null cells. Furthermore, synthesis of physiological levels of ClpB95 is less effective than coordinated expression of ClpB95/ClpB80 in protecting E. coli from thermal killing. These results provide an explanation for the conservation of the two ClpB isoforms in eubacteria and are consistent with the fact that wild type E. coli maintains the ClpB80 to ClpB95 ratio at a nearly constant value of 0.4–0.5 under a variety of stress conditions.