bluuebunny/crossref_metadata_2025 huggingface dataset:
Artifact reduction in moving‐table acquisitions using parallel imaging and multiple averages
Authors: Fautz H.P. , Honal M. , Saueressig U. , Schäfer O. , Kannengiesser S.A.R.
Published: December 2006

Two‐dimensional (2D) axial continuously‐moving‐table imaging has to deal with artifacts due to gradient nonlinearity and breathing motion, and has to provide the highest scan efficiency. Parallel imaging techniques (e.g., generalized autocalibrating partially parallel acquisition GRAPPA)) are used to reduce such artifacts and avoid ghosting artifacts. The latter occur in T2‐weighted multi‐spin‐echo (SE) acquisitions that omit an additional excitation prior to imaging scans for presaturation purposes. Multiple images are reconstructed from subdivisions of a fully sampled k‐space data set, each of which is acquired in a single SE train. These images are then averaged. GRAPPA coil weights are estimated without additional measurements. Compared to conventional image reconstruction, inconsistencies between different subsets of k‐space induce less artifacts when each k‐space part is reconstructed separately and the multiple images are averaged afterwards. These inconsistencies may lead to inaccurate GRAPPA coil weights using the proposed intrinsic GRAPPA calibration. It is shown that aliasing artifacts in single images are canceled out after averaging. Phantom and in vivo studies demonstrate the benefit of the proposed reconstruction scheme for free‐breathing axial continuously‐moving‐table imaging using fast multi‐SE sequences. Magn Reson Med 57:226–232, 2007. © 2007 Wiley‐Liss, Inc.
Correlation of proton transverse relaxation rates (R2) with iron concentrations in postmortem brain tissue from alzheimer's disease patients
Authors: House Michael J. , St. Pierre Timothy G. , Kowdley Kris V. , Montine Thomas , Connor James , Beard John , Berger Jose , Siddaiah Narendra , Shankland Eric , Jin Lee‐Way
Published: December 2006

Iron accumulates in the Alzheimer's disease (AD) brain and is directly associated with β‐amyloid pathology. The proton transverse relaxation rate (R2) has a strong linear relationship with iron concentrations in healthy brain tissue; however, an independent test of this relationship has not been extended to AD brain tissue. In this study in vitro single spin‐echo (SE) measurements were made on tissue samples from four human AD brains using a 4.7T MRI research scanner. R2 values were calculated for 14 cortical and subcortical gray matter (GM) and white matter (WM) regions. Atomic absorption spectroscopy was used to measure iron concentrations in the corresponding excised brain regions. Significant positive linear correlations were observed between R2 values and iron concentrations in GM regions assessed across individual tissue samples and data averaged by brain region. With the use of a predictive model for R2, a threshold iron concentration of 55 μg Fe/g wet tissue was determined above which R2 appears to be dominated by the affects of iron in AD brain tissue. High‐field MRI may therefore be a useful research tool for assessing brain iron changes associated with AD. Magn Reson Med 57:172–180, 2007. © 2006 Wiley‐Liss, Inc.
Actual flip‐angle imaging in the pulsed steady state: A method for rapid three‐dimensional mapping of the transmitted radiofrequency field
Authors: Yarnykh Vasily L.
Published: December 2006

A new method has been developed for fast image‐based measurements of the transmitted radiofrequency (RF) field. The method employs an actual flip‐angle imaging (AFI) pulse sequence that consists of two identical RF pulses followed by two delays of different duration (TR1 < TR2). After each pulse, a gradient‐echo (GRE) signal is acquired. It has been shown theoretically and experimentally that if delays TR1 and TR2 are sufficiently short and the transverse magnetization is completely spoiled, the ratio r = S2/S1 of signal intensities S1 and S2, acquired at the beginning of the time intervals TR1 and TR2, depends on the flip angle (FA) of applied pulses as r = (1 + n * cos(FA))/(n + cos(FA)), where n = TR2/TR1. The method allows fast 3D implementation and provides accurate B1 measurements that are highly insensitive to T1. The unique feature of the AFI method is that it uses a pulsed steady‐state signal acquisition. This overcomes the limitation of previous methods that required long relaxation delays between sequence repetitions. The method has been shown to be useful for time‐efficient whole‐body B1 mapping and correction of T1 maps obtained using a variable FA technique in the presence of nonuniform RF excitation. Magn Reson Med 57:192–200, 2007. © 2006 Wiley‐Liss, Inc.
Classification of spatiotemporal hemodynamics from brain perfusion MR images using expectation‐maximization estimation with finite mixture of multivariate gaussian distributions
Authors: Wu Yu‐Te , Chou Yen‐Chun , Guo Wan‐Yuo , Yeh Tzu‐Chen , Hsieh Jen‐Chuen
Published: December 2006

The ability to cluster different perfusion compartments in the brain is critical for analyzing brain perfusion. This study presents a method based on a mixture of multivariate Gaussians (MoMG) and the expectation‐maximization (EM) algorithm to dissect various perfusion compartments from dynamic susceptibility contrast (DSC) MR images so that each compartment comprises pixels of similar signal‐time curves. This EM‐based method provides an objective way to 1) delineate an area to serve as the in‐plane arterial input function (AIF) of the feeding artery for adjacent tissues to better quantify the relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT); 2) demarcate regions with abnormal perfusion derangement to facilitate diagnosis; and 3) obtain parametric maps with supplementary information, such as temporal scenarios and recirculation of contrast agent. Results from normal subjects show that perfusion cascade manifests (in order of appearance) the arteries, gray matter (GM), white matter (WM), veins and sinuses, and choroid plexus mixed with cerebrospinal fluid (CSF). The averaged rCBV, rCBF, and MTT ratios between GM and WM are in good agreement with those in the literature. Results from a patient with cerebral arteriovenous malformation (CAVM) showed distinct spatiotemporal characteristics between perfusion patterns, which allowed differentiation between pathological and nonpathological areas. Magn Reson Med 57:181–191, 2007. © 2006 Wiley‐Liss, Inc.
Compensation for spin‐lock artifacts using an off‐resonance rotary echo in T1ρoff‐weighted imaging
Authors: Witschey Walter R.T. , Borthakur Arijitt , Elliott Mark A. , Mellon Eric , Niyogi Sampreet , Wang Chenyang , Reddy Ravinder
Published: December 2006

The origin of image artifacts in an off‐resonance spin‐locking experiment is shown to be imperfections in the excitation flip angle. A pulse sequence for off‐resonance spin locking is implemented that compensates for imperfections in the excitation flip angle through an off‐resonance rotary echo. The off‐resonance rotary echo alternates the frequency offset and phase of the RF transmitter during two spin‐locking pulses of equal duration. The underlying theory is detailed, and MR images demonstrate the effectiveness of the technique in agarose gel phantoms and in in vivo human brain at 3T. Magn Reson Med 57:2–7, 2007. © 2006 Wiley‐Liss, Inc.
Impact of decision‐making in a multidisciplinary perinatal team
Authors: Bijma Hilmar H. , Van der Heide Agnes , Wildschut Hajo I. J. , Van der Maas Paul J. , Wladimiroff Juriy W.
Published: December 2006

Objectives

To describe the characteristics of decision‐making about management of unborn infants with serious anomalies by a multidisciplinary perinatal team.

To evaluate the impact of multidisciplinary team discussions on the degree to which decisions about the management of unborn infants with serious anomalies are supported.

To evaluate the impact of the team discussions on the arguments used by physicians for their preferences concerning management.

Methods

Prospective analysis of 78 cases discussed within the multidisciplinary perinatal team of a tertiary centre by means of an anonymous one‐page questionnaire with structured questions pertaining to the opinion of the responder on medical management of each case.

Results

We did not find systematic differences between specialties prior to the discussion of cases. However, discussion with the multidisciplinary perinatal team improved decision‐making about management of unborn infants with serious anomalies by enhancing the degree of support for the decisions taken. The discussions of the team did not change the physicians' arguments mentioned for their preferences.

Conclusion

Multidisciplinary team discussions improve decision‐making about management of unborn infants with serious congenital anomalies. Copyright © 2006 John Wiley & Sons, Ltd.
Prenatal diagnosis for a novel homozygous mutation in PKLR gene in an Indian family
Authors: Gupta Neerja , Bianchi Paola , Fermo Elisa , Kabra Madhulika , Warang Prashant , Kedar Prabhakar , Gupta Nomeeta , Colah Roshan
Published: December 2006

Objective

To provide prenatal diagnosis of pyruvate kinase deficiency by direct DNA analysis in an Indian family.

Materials and Method

This case report describes diagnosis of a novel homozygous mutation in PKLR gene that subsequently helped the family in the next pregnancy.

Results

Advancement in molecular genetics has resulted in the prenatal diagnosis of relatively uncommon genetic disorders like pyruvate kinase deficiency.

Conclusion

This case reiterates the importance of application of molecular genetics in clinical practice and prenatal diagnosis especially for rare, incurable genetic disorders. Copyright © 2006 John Wiley & Sons, Ltd.
Pregnancy and postnatal outcome of mosaic isochromosome 20q
Authors: Robinson W. P. , McGillivray B. , Friedman J. M.
Published: December 2006

Prenatally diagnosed mosaicism for isochromosome 20q is generally reported in association with a normal outcome at birth and is rarely confirmed postnatally. However, the origin of these abnormal cells is unclear and there are few reports of long‐term outcomes. We present an additional case of prenatally detected isochromosome 20q, with normal outcome up to age 3.6 years. The abnormal cells, while present at high levels in the amniotic fluid, could not be confirmed in placenta or fetal blood. Nonetheless, based on a review of the literature, the level of isochromosome 20q cells found is associated with risk of abnormal outcome, suggesting a possible effect in some cases. Copyright © 2006 John Wiley & Sons, Ltd.
Free fetal DNA is not increased before 20 weeks in intrauterine growth restriction or pre‐eclampsia
Authors: Crowley A. , Martin C. , Fitzpatrick P. , Sheils O. , O'Herlihy C. , O'Leary J. J. , Byrne B. M.
Published: December 2006

Background

The aim of this study was to quantify maternal plasma fetal DNA and total DNA in early pregnancy in intrauterine growth restriction (IUGR) or pre‐eclampsia (PET).

Methods

A nested case control study was carried out in a University Teaching Hospital. Plasma samples were obtained from 1993 women before 20 weeks of gestation. Pregnancies complicated by IUGR or PET were identified and compared to controls. DNA was extracted and real‐time quantitative PCR applied for the SRY and β‐actin genes. IUGR or PET groups were compared to controls using the χ2 and Wilcoxon rank sum tests.

Results

SRY was detected in 86% of IUGR (31/36), 94% of PET (15/16) and 78% of controls (56/72). The median SRY was similar in women with IUGR (28 GE/mL) or PET (30.5 GE/mL) and controls (27.5 GE/mL). β‐actin was increased in the IUGR group (3975 GE/mL) compared to controls (1835 GE/mL) (p = 0.045). Cigarette consumption was greater in the IUGR group compared to controls (p = 0.004).

Conclusions

Fetal DNA quantitation in maternal plasma before 20 weeks is not a useful predictor of IUGR or PET. β‐actin levels were elevated before 20 weeks in women with IUGR and may be a marker of maternal susceptibility to this condition. Copyright © 2006 John Wiley & Sons, Ltd.
Two‐ or three‐dimensional ultrasonography to predict pulmonary hypoplasia in pregnancies complicated by preterm premature rupture of the membranes
Authors: Gerards Franca A. , Twisk Jos W. R. , Fetter Willem P. F. , Wijnaendts Liliane C. D. , Van Vugt John M. G.
Published: December 2006

Objectives

The purpose of this study was to compare 3D lung volume measurements with 2D biometric parameters in predicting pulmonary hypoplasia in pregnancies complicated by preterm premature rupture of the membranes (PPROM).

Methods

In this prospective study, 18 pregnancies complicated by PPROMs at a mean 21 weeks' gestation (range 14–32 weeks) were examined. The 3D lung volume measurements and the following 2D biometric parameters were measured: thoracic circumference (TC) versus gestational age or femur length (FL), the TC/abdominal circumference (AC) ratio and the thoracic area/heart area (TA/HA) ratio. The sensitivity, specificity, positive and negative predictive value of each measurement to diagnose pulmonary hypoplasia were compared. Pulmonary hypoplasia was diagnosed on the basis of clinical, radiological and/or pathologic criteria.

Results

The incidence of pulmonary hypoplasia was 33.3%. The best diagnostic accuracy for predicting pulmonary hypoplasia was achieved using the 3D lung volume measurements versus gestational age (sensitivity 83%, specificity 100%, positive predictive value 100% and negative predictive value 92%).

Conclusions

Three‐dimensional lung volume measurements seem to be promising in predicting pulmonary hypoplasia prenatally in pregnancies complicated by PPROM. Copyright © 2006 John Wiley & Sons, Ltd.
Parental decisions to abort or continue a pregnancy following prenatal diagnosis of chromosomal abnormalities in a setting where termination of pregnancy is not legally available
Authors: Quadrelli Roberto , Quadrelli Andrea , Mechoso Búrix , Laufer Mauricio , Jaumandreu Ciro , Vaglio Alicia
Published: December 2006

Objective

To learn about parental decisions to abort or continue a pregnancy after prenatal diagnosis of chromosomal abnormalities among the population in Uruguay.

Methods

Between 1982 and 2003, 14 656 amniocentesis and 2740 chorionic villus samplings were performed in a referral Genetic Unit. Chromosomal anomalies were found in 376 cases (2.16%) and included Down syndrome, aneuploidies in which a severe prognosis was expected, sex chromosome aneuploidy and aneuploidies with a low risk of an abnormal clinical phenotype. The couples that received abnormal results were contacted by phone and asked if they had continued or interrupted the pregnancy after the diagnosis and genetic counseling.

Results

We contacted 207 couples (55%). When confronted with Down syndrome or an aneuploidy in which a severe prognosis was expected, 89% and 96% of patients, respectively, decided to terminate the pregnancy. When confronted with sex chromosome aneuploidy or aneuploidies with a low risk of an abnormal clinical phenotype, 79% and 90% of patients, respectively, decided to continue the pregnancy.

Conclusions

The present study shows that when faced with an anomaly such as Down syndrome and aneuploidies in which a severe prognosis was expected, most of the couples decided to terminate the pregnancy, although TOP is not legally available in Uruguay. Copyright © 2006 John Wiley & Sons, Ltd.
Cancer risks in thiazolidinedione users compared to other anti‐diabetic agents
Authors: Koro Carol , Barrett Steven , Qizilbash Nawab
Published: December 2006

Purpose

We conducted three nested case‐control studies to evaluate the risk of breast, colon, and prostate cancers developing in patients exposed to thiazolidinediones (TZDs) compared with other anti‐diabetic agents.

Methods

Cancer cases were matched to five controls by age, gender, calendar year, and time in the database from a cohort of 1 26 971 diabetic patients taking anti‐diabetic medication in the US Integrated Healthcare Information Services database. Five hundred thirteen breast cancer cases were matched with 2557 controls, 408 cases of colon cancer were matched with 2027 controls and 643 cases of prostate cancer were matched with 3176 controls. Exposure to an anti‐diabetic agent within 90 days preceding the index date was defined as recent exposure and at any time during the follow‐up was defined as ever exposed.

Results

The adjusted odds ratios and 95%CI of cancer from ever exposure to TZDs compared to oral monotherapy, oral dual therapy, oral triple therapy, insulin monotherapy, insulin and oral therapy and all non‐TZD anti‐diabetic agents were, respectively for breast cancer: 0.91 (0.69–1.20), 0.80 (0.56–1.14), 0.87 (0.32–2.35), 1.27 (0.61–2.67), 0.71 (0.36–1.37), 0.89 (0.68–1.15); for colon cancer: 1.06 (0.80–1.40), 1.12 (0.77–1.63), 1.73 (0.39–7.78), 4.46 (1.05–19.00), 1.06 (0.50–2.26) 1.03 (0.80–1.32) and for prostate cancer: 1.08 (0.85–1.37), 0.89 (0.66–1.21); 0.82 (0.33–2.06); 1.80 (0.79–4.07), 1.10 (0.55–2.18), 1.04 (0.83–1.31). Results for exposure within 90 days of the date of the cancer were similar.

Conclusions

Our findings suggest that the effect of TZDs on the likelihood of development of the cancers studied (colon, prostate and breast) appears to be neutral and do not support a beneficial or deleterious effect of TZD on the cancers studied. Copyright © 2006 John Wiley & Sons, Ltd.
Asthma drug use and the development of Churg–Strauss syndrome (CSS)
Authors: Harrold Leslie R. , Patterson M. Kay , Andrade Susan E. , Dube Timothy , Go Alan S. , Buist A. Sonia , Chan K. Arnold , Weller Peter F. , Wechsler Michael E. , Yood Robert A. , Davis Kourtney J. , Platt Richard , Walker Alexander M.
Published: December 2006

Purpose

Case reports suggest that leukotriene modifier use may be associated with the onset of Churg–Strauss syndrome (CSS). Using pooled data from two nested case‐control studies, we examined the association between asthma drug use and the development of CSS.

Methods

The study was performed in three US managed care organizations and a US national health plan with chart access and complete electronic pharmacy data, with a covered population of 13.9 million. There were 47 cases of possible or definite CSS and 4700 asthma drug user controls identified between January 1, 1995 and December 31, 2002. We examined exposure to asthma drugs in cases and controls, including leukotriene modifiers (6 cases and 202 controls), in the two to 6 months prior to the onset of adjudicated CSS.

Results

While the crude association between use of leukotriene modifiers and CSS was strong (odds ratio (OR) 4.00, 95% confidence interval (CI): 1.49–10.60), in a multivariable analysis controlling for use of oral corticosteroids, inhaled corticosteroids, and number of categories of asthma drugs dispensed, there was no significant association (OR 1.32, 95% CI: 0.44–3.96). Use of inhaled and oral corticosteroids, evaluated as markers of asthma severity, were associated with CSS (OR 3.07, 95% CI: 1.34–7.03 and OR 5.36, 95% CI: 2.51–11.45, respectively).

Conclusions

No association was found between CSS and leukotriene modifiers after controlling for asthma drug use However, it is not possible to rule out modest associations with asthma treatments given CSS is so rare and so highly correlated with asthma severity, suggesting further investigation is warranted. Copyright © 2006 John Wiley & Sons, Ltd.
Reactive acrylic liquid rubber with terminal and pendant carboxyl groups as a modifier for epoxy resin
Authors: Ratna D. , Banthia A.K.
Published: December 2006

Reactive acrylate rubbers with the terminal and pendent carboxyl groups have been investigated as a modifier for a room temperature curing epoxy resin. The liquid rubbers with varying molecular weights and carboxyl‐functionality were synthesized by bulk polymerization of 2‐ethyl hexyl acrylate using acrylic acid as a comonomer. The liquid rubbers were characterized by FTIR, 13C NMR spectroscopic analysis, nonaqueous titration, vapor pressure osmometry, and solubility characteristics. The liquid rubbers were incorporated into the epoxy resin by the prereact method and the effect of functionality on impact properties of the modified networks were investigated. The results were explained in terms of dynamic mechanical properties and morphology analyzed by scanning electron microscope (SEM). Polym. Eng. Sci. 47:26–33, 2007. © 2006 Society of Plastics Engineers.
A comprehensive experimental study and numerical modeling of parison formation in extrusion blow molding
Authors: Yousefi Azizeh‐Mitra , Collins Paul , Chang Stephanie , DiRaddo Robert W.
Published: December 2006

Parison dimensions in extrusion blow molding are affected by two phenomena, swell due to stress relaxation and sag drawdown due to gravity. It is well established that the parison swell and sag are strongly dependent on the die geometry and the operating conditions. The availability of a modeling technique ensures a more accurate prediction of the entire blow molding process, as the proper prediction of the parison formation is the input for the remaining process phases. This study considers both the simulated and the experimental effects of the die geometry, the operating conditions, and the resin properties on the parison dimensions using high density polyethylene. Parison programming with a moving mandrel and the flow rate evolution in intermittent extrusion are also considered. The parison dimensions are measured experimentally by using the pinch‐off mold technique on two industrial scale machines. The finite element software BlowParison® developed at IMI is used to predict the parison formation, taking into account the swell, sag, and nonisothermal effects. The comparison between the predicted parison/part dimensions and the corresponding experimental data demonstrates the efficiency of numerical tools in the prediction of the final part thickness and weight distributions. POLYM. ENG. SCI., 47:1–13, 2007. © 2006 Society of Plastics Engineers
Nitroxyls for scorch suppression, cure control, and functionalization in free‐radical crosslinking of polyethylene
Authors: Chaudhary Bharat Indu , Chopin Lamy , Klier John
Published: December 2006

This paper describes the use of 2,2,6,6‐tetramethylpiperidinyl‐oxy (TEMPO) derivatives for scorch suppression, cure control, and functionalization in peroxide crosslinking of polyethylene. When 4‐hydroxy 2,2,6,6‐tetramethylpiperidin‐1‐oxyl was used for scorch suppression, there was often a loss in ultimate degree of crosslinking. In contrast, with bis(1‐oxyl‐2,2,6,6‐tetramethylpiperidine‐4‐yl)sebacate, both scorch suppression and ultimate degree of crosslinking were enhanced. A model study in hexadecane showed that TEMPO radicals terminate with carbon‐centered radicals formed as a consequence of peroxide homolysis and propagation steps. This termination occurs preferentially over peroxide‐initiated crosslinking and results in TEMPO‐grafted polymer. In addition to polymer radical formation, several additional reaction pathways are available following thermal homolysis of the peroxide, including unimolecular disassociation of the peroxy radical to yield a methyl radical and a ketone, and proton extraction from one of several substrates by the peroxy radical to yield an alkyl radical and an alcohol. This study reveals that the reaction rate is limited by the rate of peroxide homolysis, and proceeds to statistical products with little or no preference for any specific species. The implication is that choice of peroxide is a dominant controlling factor over whether the TEMPO derivatives are ultimately grafted to the polymer or are bound to small alkyl radicals. POLYM. ENG. SCI., 47:50–61, 2007. © 2006 Society of Plastics Engineers
Recovery and characterization of pure poly(3,4‐ethylenedioxythiophene) via biomimetic template polymerization
Authors: Huh Pil‐Ho , Kim Seong‐Cheol , Kim Young‐Hoon , Kumar Jayant , Kim Bong‐Soo , Jo Nam‐Ju , Lee Jang‐Oo
Published: December 2006

The fundamental properties of pure poly(3,4‐thylenedioxythiophene) (PEDOT), one of the most common electrically conducting organic polymers, are the key to the development of more prominent applications in which PEDOT and its derivatives can be utilized. Conducting molecular complex of PEDOT with silica was synthesized in the presence of charged silica template by the in situ biomimetic polymerization. To remove silica from PEDOT/template complex, hydrofluoric acid was used to etch silica particles. The electrochemical, thermal, and optical properties of pure PEDOT recovered were investigated in comparison with those of EDOT monomer or PEDOT with template by using UV–vis–near–IR spectra, cyclic voltammetry, thermogravimetric analysis, and fluorescence spectra. POLYM. ENG. SCI., 47:71–75, 2007. © 2006 Society of Plastics Engineers
Kinetic analysis of two DSC peaks in the curing of an unsaturated polyester resin catalyzed with methylethylketone peroxide and cobalt octoate
Authors: Martin J.L.
Published: December 2006

The curing of an unsaturated polyester resin catalyzed with methylethylketone peroxide and cobalt octoate as promoter is studied by DSC at different heating rates. A high promoter/peroxide ratio is used. The DSC curves show two exothermic peaks. It has been assumed that they represent two independent cure reactions. A set of kinetic parameters for each DSC peak has been obtained. They describe the overall cure process using an empirical kinetic model. Nth order and autocatalytic kinetic functions have been employed. A computer program was developed to calculate the degrees of conversion associated with each peak, and to evaluate the kinetic parameters. The calculation algorithm uses the Runge–Kutta numerical integration and the “downhill simplex method.” This methodology permits to find all kinetic parameters simultaneously. DSC experimental data are very well fitted. The simulated first peak occurs always before the second one, and the fraction of reaction heat associated with the first peak over the overall reaction heat decreases with heating rate. Moreover, activation energies are in good agreement with the tabulated values for typical free radical polymerization induced by thermal and redox decomposition of the peroxides. POLYM. ENG. SCI., 47:62–70, 2007. © 2006 Society of Plastics Engineers
Kinetic Regularities of the Heat Release for the Interaction of Some Organic Compounds with Ammonium Nitrate
Authors: Rubtsov Yury I. , Kazakov Anatoly I. , Lempert David B. , Manelis George B.
Published: December 2006

Ammonium nitrate (AN) is used as an oxidant in a series of systems with a wide spectrum of applications, from explosive compositions up to smokeless stoichiometric self‐burning compositions with low combustion temperature. The knowledge of the thermal stability of such compositions is of great importance in using them in practice. In this work the research of kinetics of heat release in the interaction of AN with different organic compounds has been performed using the automatic differential calorimeter.
Differential Scanning Calorimetric Study of HTPB based Composite Propellants in Presence of Nano Ferric Oxide
Authors: Patil Prajakta R. , Krishnamurthy V. N. , Joshi Satyawati S.
Published: December 2006

A comparative study of the thermal decomposition of ammonium perchlorate (AP)/hydroxy terminated polybutadiene (HTPB) based composite propellants has been carried out in presence and absence of nano iron oxide at different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry. The pronounced effect was a lowering of the high temperature decomposition by 49 °C. A higher heat release up to 40% was observed in presence of nano ferric oxide (3.5 nm). The kinetic parameters were evaluated using the Kissinger method. The increase of the rate constant in the catalyzed propellant confirmed the enhancement of the catalytic activity of ammonium perchlorate. The scanning electron micrographs of nano Fe2O3 incorporated in HTPB revealed a well‐separated characteristic necklace‐like structure of α‐Fe2O3 particles at high magnification.
Effect of Fe2O3 in Fe2O3/AP Composite Particles on Thermal Decomposition of AP and on Burning Rate of the Composite Propellant
Authors: Ma Zhenye , Li Fengsheng , Bai Huaping
Published: December 2006

A technique of composite processing of Fe2O3 and ammonium perchlorate (AP) was employed in making the propellant. The effects of composite processing of Fe2O3 on catalytic activity, on the thermal decomposition of AP, and on the burning rate of the composite propellant were investigated in this paper. Fe2O3/AP composite particles were prepared by a novel solvent‐nonsolvent method. The results show that AP is successfully coated on the surface of Fe2O3. Composite processing of Fe2O3 and AP can improve the catalytic activity of Fe2O3. Fe2O3 exhibits better catalytic effect with increasing Fe2O3 content. The larger interface between Fe2O3 and AP and lower density of composite propellant (with the added Fe2O3/AP composite particles) are responsible for the enhancement of the catalytic activity of Fe2O3.
Changes in Pore Size Distribution upon Thermal Cycling of TATB‐based Explosives Measured by Ultra‐Small Angle X‐Ray Scattering
Authors: Willey Trevor M. , van Buuren Tony , Lee Jonathan R. I. , Overturf George E. , Kinney John H. , Handly Jeff , Weeks Brandon L. , Ilavsky Jan
Published: December 2006

Hot‐spot models of initiation and detonation show that voids or porosity ranging from nanometer to micrometer in size within highly insensitive energetic materials affect initiability and detonation properties. Thus, the knowledge of the void size distribution, and how it changes with the volume expansion seen with temperature cycling, are important to understanding the properties of the insensitive explosive 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB). In this paper, void size distributions in the 2 nm to 2 μm regime, obtained from small‐angle X‐ray scattering measurements, are presented for LX‐17‐1, PBX‐9502, and ultra‐fine TATB formulations, both as processed and after thermal cycling. Two peaks were observed in the void size distribution: a narrow peak between 7–10 nm and a broad peak between 20 nm and about 1 mm. The first peak was attributed to porosity intrinsic to the TATB crystallites. The larger pores were believed to be intercrystalline, a result of incomplete consolidation during processing and pressing. After thermal cycling, these specimens showed an increase in both the number and size of these larger pores. These results illuminate the nature of the void distributions in these TATB‐based explosives from 2 nm to 2 μm and provide empirical experimental input for computational models of initiation and detonation.
A Desorption Electrospray Ionization Mass Spectrometry Study of Aging Products of Diphenylamine Stabilizer in Double‐Base Propellants
Authors: Venter Andre , Ifa Demian R. , Cooks R. Graham , Poehlein Sara K. , Chin Anton , Ellison Dan
Published: December 2006

Double‐base propellants consisting of nitrocellulose, nitroglycerin and stabilizer undergo chemical and physical changes upon aging, leading to changes in ballistic power and presenting explosive hazards. During aging, PTFE seals of the glass ampoules used in the aging studies undergo a yellow discoloration. This report studies the discoloration of the liners using desorption electrospray ionization (DESI), a gentle surface analysis technique based on electrospray ionization. The color bodies in the PTFE liners were identified by DESI together with tandem mass spectrometry to be the nitrated derivatives of the diphenylamine stabilizer: dinitro‐, trinitro‐, and tetranitrodiphenylamine. While increased nitration decreases vapor pressure of the DPA species, an increase in solubility in the PTFE liners occurs. This may account for these species not previously being observed during early aging studies as they are preferentially absorbed into the liners, which were not extracted prior to high performance liquid‐ chromatography analysis.
Synthesis and Characterization of Two Potential Energetic Azido Esters
Authors: Pant Chandra Shekhar , Wagh Rashmi Moreshwar , Nair Jaya Kamalesh , Gore Girish Mukund , Venugopalan Sethuramasharma
Published: December 2006

Two new energetic azido esters named 1,3‐bis(azidoacetoxy)‐2‐azidoacetoxymethyl‐2‐ethylpropane (I) and 1,3‐bis(azidoacetoxy)‐2,2‐bis(azidomethyl)propane (II), have been synthesized and characterized by IR, NMR and Elemental Analysis. Thermal studies revealed that azido esters I and II are stable up to 180 °C and their glass transition temperatures are −47 °C and −52 °C, respectively.
HMX as an Impurity in RDX Particles: Effect on the Shock Sensitivity of Formulations Based on RDX
Authors: Borne Lionel , Ritter Helmut
Published: December 2006

Two main kinds of heterogeneities are pointed out in RDX particles in using optical microscopy with matching refractive index and scanning electron microscopy. These are HMX impurities and solvent inclusions.
Germline copy number polymorphisms involving larger than 100 kb are uncommon in normal subjects
Authors: Liu Wennuan , Chang Baoli , Li Tao , Dimitrov Latchezar , Kim Seungchan , Kim Jin Woo , Turner Aubrey R. , Meyers Deborah A. , Trent Jeffery M. , Zheng Siqun Lilly , Isaacs William B. , Xu Jianfeng
Published: December 2006

BACKGROUND

Recent studies using ROMA and Array‐CGH suggest that germline copy number polymorphisms (CNPs) involving >100 kb are common in humans.

METHODS

In this study, we used the Affymetrix GeneChip 100K single nucleotide polymorphisms (SNP) mapping panel to further examine the type and frequency of germline CNPs in the genome. By utilizing the allele intensity data generated while genotyping ∼116,000 SNPs among 23 subjects from 4 families, we were able to detect multiple CNPs.

RESULTS

However, in contrast to several previous studies, we found that CNPs >100 kb are rare in the genome but CNPs involving 100s–1,000s of base pairs are more common.

CONCLUSIONS

We have demonstrated the utility of this approach, which has an important advantage over other methods because it is able to simultaneously assess both CNPs and SNPs, and therefore has great potential in genetic association studies of common diseases. Prostate 67:227–233, 2007. © 2006 Wiley‐Liss, Inc.
BCAR1 expression in prostate cancer: Association with 16q23 LOH status, tumor progression and EGFR/KAI1 staining
Authors: Fromont Gaëlle , Vallancien Guy , Validire Pierre , Levillain Pierre , Cussenot Olivier
Published: December 2006

BACKGROUND

The 16q23 locus has been recently suggested in both breast and prostate cancer to contain a gene involved in disease progression. The breast cancer antiestrogen resistance 1 (BCAR1) gene, located at 16q23, contributes to many cellular processes including migration and survival, and interacts in vitro with the growth factor receptor EGFR and the metastasis suppressor KAI1.

METHODS

BCAR1, EGFR, and KAI1 expression was studied by immunohistochemistry on a tissue microarray containing 100 localized prostate cancers (LPC), 15 hormone refractory prostate cancers (HRPC), and 15 lymph node metastasis (LNM). Forty eight of the LPC were also analyzed for 16q23 LOH status using microsatellite markers.

RESULTS

BCAR1 staining was present in 25% of LPC, associated with higher Gleason score, and in 60% and 80% of, respectively, LNM and HRPC. BCAR1 expression was inversely correlated with 16q23 LOH status (P < 0.001), and was associated with high EGFR staining (P < 0.02), and negative KAI1 expression (P < 0.01).

CONCLUSIONS

BCAR1 expression in LPC seems to be regulated at least in part by genetic events. The increased expression of BCAR1 with disease progression suggests a potential interest for both prognosis and treatment. Prostate 67:268–273, 2007. © 2006 Wiley‐Liss, Inc.
Identification of a novel prostate cancer‐associated tumor antigen
Authors: Miles Amanda K. , Rogers Alistair , Li Geng , Seth Rashmi , Powe Des , McArdle Stephanie E.B. , McCulloch Thomas A. , Bishop Michael C. , Rees Robert C.
Published: December 2006

Background

The identification of antigens that distinguish cancer cells from normal cells is of major importance for the definition of therapeutic targets in human malignancies. Using sera from cancer patients, we have previously reported on the identification of immunologically recognized proteins that belong to the family of cancer testis antigens (CTAs).

Methods

A normal testicular cDNA library was screened with pooled allogeneic sera from patients with prostate cancer using a modified SEREX approach. Subsequently we have identified and characterized a novel antigen, T21, with an expression pattern similar to that of CTAs. mRNA expression of T21 was determined using a panel of whole tissues and prostate cell lines using Q‐RT‐PCR. For laser microdissection, fresh prostate cancer and benign tissue was obtained using our novel validated harvesting technique. Protein expression and cellular localization of T21 were assessed in prostate cell lines using Western blotting, confocal microscopy and flow cytometry.

Results

T21 showed tissue‐restricted mRNA expression in gastric, kidney and prostate cancers, and in normal testis and prostate tissues. Following laser microdissection, T21 was significantly over‐expressed in malignant compared to benign prostatic epithelium. We have demonstrated expression of T21 at the protein level and confocal microscopy on PC3 cells probed with a T21‐monospecific antibody revealed cytoplasmic localization of T21 protein.

Conclusions

The highly restricted expression pattern of T21 makes it an attractive vaccine target for prostate cancer. Several CTAs reportedly induce cytotoxic T‐lymphocyte responses, therefore it is reasonable to assume that T21 will be a valuable target for cancer immunotherapy. Prostate 67:274–287, 2007. © 2006 Wiley‐Liss, Inc.
TGFBR3 loss and consequences in prostate cancer
Authors: Sharifi Nima , Hurt Elaine M. , Kawasaki Brian T. , Farrar William L.
Published: December 2006

Background

Resistance to transforming growth factor‐beta (TGF‐β) is important in tumorigenesis. TGF‐β resistance mechanisms in prostate cancer are not well understood.

Methods

We have conducted a systematic analysis of TGF‐β pathway components with a meta‐analysis of seven microarray studies using Oncomine and evaluated the results of TGFBR3 expression in prostate cell lines. Furthermore, we knocked down TGFBR3 in prostate epithelial cells and analyzed the consequences of TGFBR3 knockdown.

Results

We found that TGFBR3 is the TGF‐β component most commonly downregulated among localized human prostate cancer studies. TGFBR3 knockdown led to focus formation and enhanced expression of CD133, a marker found on prostate cancer stem cells. DNA microarray analysis of TGFBR3 knockdown cells identified 101 genes regulated by TGFBR3. Seven of these genes show a corresponding decrease in clinical prostate cancer specimens, which include genes involved in prostate mass and vasculature.

Conclusions

TGFBR3 downregulation is an important step in prostate tumorigenesis. Prostate 67:301–311, 2007. © 2006 Wiley‐Liss, Inc.
Promoter hypermethylation of GSTP1, AR, and 14‐3‐3σ in serum of prostate cancer patients and its clinical relevance
Authors: Reibenwein Jochen , Pils Dietmar , Horak Peter , Tomicek Birgit , Goldner Gregor , Worel Nina , Elandt Katarzyna , Krainer Michael
Published: December 2006

OBJECTIVE

Hypermethylation of tumor suppressor genes (TSG) is thought to play an important role in tumorigenesis of prostate cancer. The main focus of research was the detection of TSG hypermethylation in cancer tissue. Our aim was to evaluate the feasibility of detection of hypermethylated genes in serum of prostate cancer patients and its correlation with clinicopathological parameters.

METHODS

One hundred twenty‐five serum samples from 62 patients with hormone refractory prostate cancer (HRPC), 14 patients with early disease, and 49 healthy controls were examined. After DNA extraction and sodium‐bisulfite treatment, conventional methylation‐specific PCR (MSP) was performed for glutathione S‐transferase P1 (GSTP1), androgen receptor (AR), and 14‐3‐3σ.

RESULTS

In serum of HRCP patients, frequency of GSTP1, AR, and 14‐3‐3σ hypermethylation was 32.2, 40.3, and 86.6%, respectively. In serum of patients with early disease frequency of GSTP1, AR, and 14‐3‐3σ, hypermethylation was 21.4, 35.7, and 85.7%. In healthy controls, frequency of GSTP1, AR, and 14‐3‐3σ hypermethylation was 0, 26.5, and 55.1%, respectively. There was a significant increase of frequency of TSG hypermethylation for GSTP1 and 14‐3‐3σ in HRPC patients, in comparison with healthy controls. GSTP1 hypermethylation in HRPC patients was significantly correlated with differentiation of cancer and metastatic disease.

CONCLUSIONS

Hypermethylation of TSG can be detected in serum of prostate cancer patients. Some hypermethylated TSG can be detected in serum of healthy controls. GSTP1 was not detectable in controls and correlated significantly with Gleason score and stage of disease. Therefore, this gene may be a promising new tool in prostate cancer diagnosis. Prostate 67: 427–432, 2007. © 2006 Wiley‐Liss, Inc.
Plasma osteopontin in comparison with bone markers as indicator of bone metastasis and survival outcome in patients with prostate cancer
Authors: Ramankulov Azizbek , Lein Michael , Kristiansen Glen , Loening Stefan A. , Jung Klaus
Published: December 2006

Background

The study was undertaken to evaluate the diagnostic and prognostic value of plasma osteopontin (OPN) in comparison to bone markers as well as the relationships between the markers and clinico‐pathological factors in prostate cancer (PCa) patients.

Methods

OPN and the bone markers carboxyterminal‐telopeptide of type I collagen, bone‐specific alkaline phosphatase (bALP), and aminoterminal‐propeptide of type I procollagen (PINP) were measured in 90 PCa patients with and without bone metastases, 35 patients with benign prostatic hyperplasia, and 29 healthy men.

Results

OPN and bone markers were significantly elevated in patients with bone metastases compared to the other groups. Significant correlations were found between all four‐bone markers (rs = 0.43–0.79, all P < 0.01). OPN correlated with tumor grade (rs = 0.23, P < 0.05). In receiver‐operating characteristics (ROC) analyses, OPN and bone markers were effective in distinguishing PCa patients with and without bone metastases showing areas under the curve (AUC) between 0.80 and 0.88 (all P < 0.001). OPN had an AUC of 0.85 that increased in combination with bALP up to 0.93 providing at the point with the highest diagnostic accuracy both a sensitivity and specificity of about 90%. Kaplan–Meier analyses and Cox proportional hazards regression models showed decreased survival of patients with high OPN and bone marker levels, while only high OPN and PINP were independent negative prognostic factors for PCa‐related death.

Conclusions

OPN alone or in combination with bone markers is useful as diagnostic marker in the detection of bone metastases and as prognosticator in the survival prediction in PCa patients. Prostate 67:330–340, 2007. © 2006 Wiley‐Liss, Inc.
The value of different screening tests in predicting prostate biopsy outcome in screening for prostate cancer data from a multicenter study (ERSPC)
Authors: Roobol M.J. , Zappa M. , Määttänen L. , Ciatto S.
Published: December 2006

BACKGROUND

Although serum PSA testing is widely used as a screening test for prostate cancer (PC), it is known that it is not specific for PC. The study described here focuses on the value of screening tests next to PSA in identifying men with an elevated risk of having PC and the differences between three centers of the European Randomised study of Screening for Prostate Cancer (ERSPC).

METHODS

The study population consists of 2,483 men with a PSA ≥4.0 ng/ml, all biopsied. We assessed data on age, serum PSA level at initial and repeat screening, prostate volume, number of positive DRE and TRUS findings, number of previous negative biopsies, and PPV of the three centers and overall. Using logistic regression analysis, predictors for biopsy outcome at repeat screening in men with a PSA value ≥4.0 ng/ml were determined on the complete dataset and per center.

RESULTS

In 2,483 men biopsied, 665 cancers were detected (PPV = 26.8%). Data show that all predictors except prostate volume loose their predictive value in men previously biopsied. In men not previously biopsied, the predictive value of DRE and TRUS vary considerably among the three centers.

CONCLUSIONS

Looking at the differences in the predictive value of screening tests in three “comparable” centers, generasibility is not as straightforward as it seems. Using a nomogram for predictive purposes developed elsewhere will require a thorough knowledge of the patient population of which it is derived, and one should interpret its results with a critical mind. Prostate 67: 439–446, 2007. © 2006 Wiley‐Liss, Inc.
Thermal emission and other characteristics of large liquefied natural gas fires
Authors: Malvos Hugues , Raj Phani K.
Published: December 2006

Three 35‐m diameter liquefied natural gas (LNG) fire tests were conducted on an insulated concrete dike in July and September of 1987. Although details of the test setup and instruments were previously reported, only limited data were published. This article presents additional data, especially of the radiant heat output of the fire, and other important results. The fire emissive power obtained from the wide angle and narrow angle radiometer data are compared with similar results from other field tests. The importance of these results in modeling the behavior of large LNG fires and predicting the thermal emissions from fires postulated to occur from large LNG releases is discussed. Also indicated in this article are the data on the spectral emission from the 35‐m diameter LNG fires. Analysis and comparison with similar data from the China Lake LNG fire on water tests are provided. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2007.
Linear deformation effect on the SWR acoustic mode in La0.67Ca0.33MnO3 manganite film
Authors: Shapovalov V. , Dyakonov V. , Aleshkevych P. , Dyakonov K. , Zhikharev I. , Kuzminski M. , Szymczak H.
Published: December 2006

In this work, the influence of linear deformation on the magnetic resonance spectrum including the surface spin wave mode in La0.67Ca0.33MnO3 manganite film grown on LiNbO3 substrate has been investigated using a microwave technique. The parameters of the spectrum are established to depend strongly on strains in the film that influence both the profile of the magnetic resonance spectrum and the mode position and intensity. The magnetostriction constants of both the bulk film and surface mode were first determined using the shift of resonance fields as a function of mechanical stress. The tensile strain is shown to favor excitation of the surface spin‐wave mode, and its influence is stronger on the film surface layer. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier injection as a cause of THz lasing excitation in SiGe/Si QW structures
Authors: Kagan M. S. , Altukhov I. V. , Sinis V. P. , Paprotskiy S. K. , Yassievich I. N. , Kolodzey J.
Published: December 2006

The evolution of THz emission, current and probe voltage in SiGe‐QW laser structures at the leading front of voltage pulse was studied. The excitation of stimulated THz emission is shown to be the result of electron injection through contacts and/or n‐Si substrate. The mechanism of intra‐center population inversion caused by carrier injection is suggested. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)