bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship Between Symptoms and Health‐Related Quality of Life in Patients Treated for Hypertension
Authors: Erickson Steven R. , Williams Brent C. , Gruppen Larry D.
Published: May 2004

Study Objective. To determine the relationship between symptoms and health‐related quality of life (HRQOL) in patients receiving drug therapy for hypertension.

Design. Cross‐sectional survey.

Setting. Outpatient general medicine and university‐based hypertension clinics.

Patients. All patients prescribed one or more antihypertensive drugs seen during a 6‐month period in the clinics.

Intervention. Data were obtained from a mailed questionnaire and medical records.

Measurements and Main Results. Symptoms were measured by a symptom count and total symptom distress. Two scores derived from the Short Form‐36 (SF‐36)—the Physical Component Summary (PCS) and the Mental Component Summary (MCS)—were used to assess HRQOL. Responses were received from 125 of 220 patients (56.8%). Mean ± SD values were 8.8 ± 7.8 for symptom count, 31.6 ± 46.2 for total symptom distress, 48.7 ± 9.3 for PCS, and 51.6 ± 10.1 for MCS. Higher symptom counts and symptom distress scores were strongly associated with lower HRQOL scores in multivariate models, with standardized coefficients from −0.62 to −0.41. These were greater in magnitude than any other predictor, including demographic information (age, sex, race, education level, income), disease variables (blood pressure, years of hypertension), and drug treatment (number of antihypertensive drugs and duration of regimen). Model‐adjusted R2 values were 0.22–0.41.

Conclusion. Symptoms have a greater impact on HRQOL than patient characteristics, blood pressure, or drug‐related factors. Among patients receiving drug therapy for hypertension, detailed review of symptoms may yield important information for assessing and improving HRQOL.
Angiotensin‐Converting Enzyme Inhibitor Therapy in Patients with Heart Failure Enrolled in a Managed Care Organization: Effect on Costs and Probability of Hospitalization
Authors: Abarca Jacob , Malone Daniel C. , Armstrong Edward P. , Zachry Woodie M.
Published: May 2004

Study Objective. To evaluate the effect of angiotensin‐converting enzyme (ACE) inhibitor therapy on risk of hospitalization and resource utilization in patients with heart failure enrolled in a managed care organization.

Design. Retrospective medical and pharmacy claims analysis.

Patients. One thousand five hundred seventy‐three patients with heart failure enrolled in a managed care organization.

Measurements and Main Results. Medical and pharmacy claims from January 1, 1997‐December 31, 1999, from a managed care organization covering approximately 350,000 individuals were analyzed. Patients aged 35 years or older with a diagnostic code for heart failure and 18 months of continuous eligibility were selected. From this group (1573 patients), two cohorts were selected based on exposure to an ACE inhibitor. Dependent variables of interest were all‐cause hospitalization and total direct medical costs during the 12‐month study period. A logistic regression model and an ordinary least‐squares model adjusting for patient demographics, comorbidities, and concomitant drug therapy were used to analyze the risk of all‐cause hospitalization and total direct medical costs, respectively. Therapy with an ACE inhibitor for 180 days was associated with a decreased risk of all‐cause hospitalization (odds ratio 0.65, p<0.0001) and lower total costs (mean $2397, p<0.001) compared with no ACE inhibitor therapy.

Conclusion. In patients with a diagnosis of heart failure, exposure to ACE inhibitor therapy is associated with fewer hospitalizations and lower total costs than no ACE inhibitor exposure.
Delaying the Onset of Type 2 Diabetes Mellitus in Patients with Prediabetes
Authors: Irons Brian K. , Mazzolini Timothy A. , Greene Ronald Shane
Published: May 2004

The frequency of type 2 diabetes mellitus is increasing at an alarming rate. Prediabetes, also referred to as impaired glucose tolerance (IGT) and/or impaired fasting glucose, is a major risk factor for development of type 2 diabetes mellitus. In addition, IGT has been associated with an increased risk of cardiovascular disease and mortality. Several studies have measured the effects of various interventions in patients with IGT on the development of type 2 diabetes mellitus. Intensive lifestyle modifications through alterations in diet and improvement in exercise have delayed the development of type 2 diabetes mellitus by 58% in patients with IGT. Therapy with metformin, troglitazone, or acarbose also has reduced the progression of IGT to diabetes mellitus by 31%, 49% and 25%, respectively. The mechanisms by which lifestyle interventions and drugs reduce the progression may be through alterations in insulin sensitivity. The American Diabetes Association recommends screening for prediabetes in patients who are 45 years or older and those with a body mass index of 25 kg/m2 or greater who have additional diabetes mellitus risk factors. Pharmacists can promote awareness, counsel patients on intervention strategies to delay the onset of diabetes mellitus, and screen high‐risk patients.
Photopatternable Reflective Films Produced by Nanolayer Extrusion
Authors: Tangirala R. , Baer E. , Hiltner A. , Weder C.
Published: May 2004

Novel patternable, light‐reflecting multilayer polymer films are presented. The investigated elements comprise 1024 nanolayers of two different, transparent polymers in strictly alternating fashion. Polymers with different refractive indices were employed and the individual layer thickness was controlled between 50 and 200 nm; as a result the investigated films exhibit pronounced optical interference effects. Different photoreactive additives were integrated into the multilayer films, rendering the optical characteristics of these elements tunable. One approach relied on the use of photoreactive blends of poly(methyl methacrylate) (PMMA) and up to 25 wt.‐% of trans‐cinnamic acid (CA) or trans‐methyl cinnamate (MC). Upon exposure to ultraviolet (UV) radiation, CA and MC undergo dimerization through 2+2 cycloaddition, leading to a significant decrease of the blend's refractive index. As a result, the reflectivity of the multilayer films based on these photoreactive blends changes considerably upon photoreaction. The second approach was based on the use of blends of PMMA and 2‐(2′‐benzoylphenyl)benzoxazole (BzPO), a ‘caged’ photoluminescent dye. This benzoyl ester of 2‐(2′‐hydroxyphenyl)benzoxazole (HPBO) is not photoluminescent, but upon exposure to appropriate UV radiation, the ester bond is cleaved, and the photoluminescent HPBO is quantitatively restored. Thus, using conventional photolithographic techniques, reflective multilayer films were patterned with photoluminescent designs.
Randomized study of the safety and clinical utility of rotational angiography versus standard angiography in the diagnosis of coronary artery disease
Authors: Maddux James T. , Wink Onno , Messenger John C. , Groves Bertron M. , Liao Robert , Strzelczyk Jodi , Chen Shiuh‐Yung , Carroll John D.
Published: May 2004

This study evaluates the safety and clinical utility of rotational angiography in the diagnosis of coronary artery disease. High‐speed rotational angiography is a newly available angiographic modality that gives a dynamic multiple‐angle perspective of the coronary tree during a single contrast injection. We prospectively randomized 56 patients referred for diagnostic coronary angiography to either standard or rotational angiography. Contrast and radiation utilization were compared between the two groups. The number of additional cine acquisitions needed was used to determine adequacy of the diagnostic study protocol. Rotational angiography was successfully completed in all subjects. There was a 33% reduction in contrast utilization in the rotational group as compared to the standard group (35.6 ± 12.6 vs. 52.8 ± 10.7 ml, respectively; P < 0.0001). Additionally, there was a 28% reduction in total radiation exposure in the rotational group as compared to the standard group (39.0 ± 18.5 vs. 53.9 ± 23.4 Gycm2, respectively; P = 0.01). Total whole‐body radiation exposure to the primary operator was 144 mrem with rotational angiography and 170 mrem with standard angiography. Procedure time tended to be shorter for rotational angiography (353.9 ± 146.7 vs. 396.8 ± 165.8 s; P = 0.3). Rotational coronary angiography can be rapidly performed in any patient and provides a significant reduction in contrast and radiation utilization while at the same time providing adequate angiographic data to complement or replace standard coronary angiography in the evaluation of coronary artery disease. Catheter Cardiovasc Interv 2004;62:167–174. © 2004 Wiley‐Liss, Inc.
Vascular complications following coronary intervention correlate with long‐term cardiac events
Authors: Kuchulakanti Pramod K. , Satler Lowell F. , Suddath William O. , Pichard Augusto D. , Kent Kenneth M. , Pakala Rajbabu , Canos Daniel A. , Pinnow Ellen E. , Rha Seung‐Woon , Waksman Ron
Published: May 2004

We aimed to study the consequences and late outcomes of patients who experienced peripheral vascular complications (PVCs) following percutaneous coronary interventions (PCI). A retrospective analysis of the medical records of 10,669 patients who underwent PCI and experienced PVC between 1995 and 2002 was conducted. One thousand ninety‐six patients (10.27% of the study cohort) had PVC post‐PCI. After PCI, patients with PVC had higher rates of in‐hospital complications (P < 0.001) when compared to patients without PVC, including Q‐wave myocardial infarction (MI; 1.2% vs. 0.3%), coronary artery bypass grafting (CABG; 3.8% vs. 0.6%), and death (4.0% vs. 1.0%). At 1‐year follow‐up, late complications of MI (37.4% vs. 25.4%), non‐Q‐wave MI (34.9% vs. 22.7%), death (12.9% vs. 5.9%), and CABG (5.7% vs. 4.5%) were higher (< 0.001) in patients with PVC compared to those without. Multivariate analysis identified PVC as a significant predictor of 1‐year mortality (P = 0.045). This study underscores the need to make diligent efforts to minimize PVC and follow up these patients for future coronary events. Cardiovasc Interv 2004;62:181–185. © 2004 Wiley‐Liss, Inc.
Complication with an embolic protection device during carotid angioplasty
Authors: Cardaioli Paolo , Giordan Massimo , Panfili Marco , Chioin Raffaello
Published: May 2004

A case of carotid artery stenting with an AngioGuard cerebral protection device is described in a patient with tight internal carotid stenosis. Deployment of AngioGuard induced sudden severe vasospasm, with subsequent minor stroke. According to our observations, AngioGuard may cause a vasospastic response with adverse neurologic effects. Catheter Cardiovasc Interv 2004;62:234–236. © 2004 Wiley‐Liss, Inc.
Influence of hot pressing on the microstructure and fracture toughness of two pressable dental glass–ceramics
Authors: Albakry Mohammad , Guazzato Massimiliano , Swain Michael Vincent
Published: May 2004

Empress 1 and Empress 2 are well‐known pressable all‐ceramic dental materials that have generated substantial interest for many clinicians and patients. These two materials are reputed to benefit from heat pressing during the laboratory fabrication procedures, leading to better crystal distribution within a glass matrix, and hence an improved strength. The present study aimed to evaluate the effect of heat pressing on fracture toughness, microstructural features, and porosity. Results showed that Empress 1 had similar fracture toughness values before the pressing procedure, after it, and after the repressing procedure. The microstructural features were also similar among these specimens, but a more uniform distribution of leucite crystals was observed following the pressing and repressing procedures. Empress 2 demonstrated two different fracture toughness values. This was associated with the alignment of lithium disilicate crystals that occurred after the pressing and repressing procedures, which led to different indentation induced crack lengths, depending upon whether cracks propagated parallel to or perpendicular to the aligned crystals, the former having lower toughness than those that propagated in the perpendicular direction. Porosity, in terms of both the size and number of pores, was found to decrease after the pressing and repressing procedures for both materials. Repressing resulted in significant growth of the lithium disilicate crystals in Empress 2, but there was no change for the leucite crystals in Empress 1. The change in the lithium disilicate crystals' size did not have a noticeable effect on the fracture toughness of Empress 2. It was concluded that heat pressing did not significantly affect the fracture toughness of Empress 1, but resulted in two different values for Empress 2. It also decreased the size and number of pores for both materials, which could contribute to the strength improvement found after heat pressing, which has been reported in previous studies. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 99–107, 2004
Infraciliature and myoneme system ofCampanella umbellaria(Protozoa, Ciliophora, Peritrichida)
Authors: Shi Xinlu , Warren Alan , Yu Yuhe , Shen Yunfen
Published: May 2004

The infraciliature and myoneme system ofCampanella umbellariawere revealed using the protargol impregnation technique. The main characteristics of the infraciliature are the peristomial ciliary rows (haplokinety and polykineties), which make four and a half turns around the peristomial disc before plunging into the infundibulum, and the aboral infraciliature, which is made up of the aboral ciliary wreath (trochal band) and the scopula. The myoneme system is composed of: 1) longitudinal fibers, which include 60–84 (mean 72.3) short longitudinal fibers, 40–56 (mean 45.8) medium‐length longitudinal fibers, and numerous long longitudinal fibers; and 2) circular fibers, which include 8–12 (mean 9.3) peristomial ring fibers, linking fibers, support fibers, and peristomial disc fibers. The various fibers inC. umbellariaare interconnected to form a single myoneme system that may act as a cell skeleton as well as providing the mechanism by which the zooid contracts and relaxes. J. Morphol. 261:43–51, 2004. © 2004 Wiley‐Liss, Inc.
The spermatozoon of Eurasian murine rodents: Its morphological diversity and evolution
Authors: Breed William G.
Published: May 2004

The murine rodents are the most speciose subfamily of mammals. Here the morphology of the spermatozoon, as determined by scanning and transmission electron microscopy of representative species from four Eurasian clades, is described. Much interspecific variability in all components of the spermatozoon was found to occur, although most species have a bilaterally flattened sperm head with a single apical hook of variable length and orientation. Ultrastructural observations indicate that this apical hook invariably contains a nuclear projection as well as a large extension of the subacrosomal cytoskeleton, as a perforatorium rostrally, and a complex asymmetrical acrosomal extension. These spermatozoa also have relatively long tails that are attached to the lower concave surface of the sperm head. Uniquely, in species in the Apodemus clade, the apical hook is orientated caudally. In a few species a highly derived sperm head morphotype that does not contain an apical hook is present. These sperm heads vary in morphology from being globular in two species of Bandicota, to bilaterally flattened and paddle‐shaped in Tokudaia and Micromys. In spermatozoa of the latter two genera the subacrosomal cytoskeleton, which is less extensive than in species with a hooked sperm head, forms an apical extension, but that is not the case in Bandicota. In all species where the sperm head lacks an apical hook the acrosome is more symmetrical. The sperm tail is much shorter in these species, with attachment to the head occurring on the ventral surface in Tokudaia and basal in Micromys and the two species of Bandicota. As the sperm head morphotype with a complex apical hook is present in all the major clades of murine rodents, it is likely to be a plesiomorphic character within each of these clades, with the nonhooked sperm heads, which vary greatly in structure between species of the different lineages, probably being independently derived. The ultrastructural organization of the sperm head of Bandicota, but not those of Micromys or Tokudaia, suggest divergence in some of the morphological events associated with sperm–egg interaction at the time of fertilization. J. Morphol. 261:52–69, 2004. © 2004 Wiley‐Liss, Inc.
Radiation‐Grafted Polymerization from a Gas Phase to Form Polymeric Layers on Metal Surfaces
Authors: Tsetlin Boris L. , Golubev Vladimir N. , Khokhlov Alexei R. , Dementjev Alexei P. , Maslakov Konstantin I. , Tsetlin Mikhail B. , Kalita Vasiliy I.
Published: May 2004

Summary: Experimentally it is shown that, under irradiation in an atmosphere of non‐saturated vinylidene chloride vapors, a polymeric layer is formed on the surface of oxidized titanium samples. The thickness of this layer increases with the increase of thickness of the oxide film. Such a dependence corresponds to the current understanding of the mechanism of formation and migration of the active excited centers that initiate grafted polymerization.

Wide range XPS spectra of oxidized titanium samples after PVDC grafting from a gas phase.

image

Wide range XPS spectra of oxidized titanium samples after PVDC grafting from a gas phase.
Materials for polymer electronics applications – semiconducting polymer thin films and nanoparticles
Authors: Asawapirom U. , Bulut F. , Farrell T. , Gadermaier C. , Gamerith S. , Güntner R. , Kietzke T. , Patil S. , Piok T. , Montenegro R. , Stiller B. , Tiersch B. , Landfester K. , List E.J.W. , Neher D. , Sotomayor Torres C. , Scherf U.
Published: May 2004

The paper presents two different approaches to nanostructured semiconducting polymer materials: (i) the generation of aqueous semiconducting polymer dispersions (semiconducting polymer nanospheres SPNs) and their processing into dense films and layers, and (ii) the synthesis of novel semiconducting polyfluorene‐block‐polyaniline (PF‐b‐PANI) block copolymers composed of conjugated blocks of different redox potentials which form nanosized morphologies in the solid state.
Fast Gaussian beam technique for the analysis of composite horn‐reflector antenna systems
Authors: Lucci L. , Pelosi G. , Roederer A. G. , Selleri S. , Toso G.
Published: May 2004

A fast and accurate procedure for the analysis of composite horn‐reflector antenna systems with electrically large dimensions is here presented. The horn analysis is carried out exploiting the mode matching (MM) and the combined field‐integral equation (CFIE) techniques. For the reflector characterization a PO‐based Gaussian beam asymptotic technique is used. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 95–100, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20219
A broadband E‐shaped patch antenna with a microstrip‐compatible feed
Authors: Ge Yuehe , Esselle Karu P. , Bird Trevor S.
Published: May 2004

A broadband low‐profile E‐shaped patch antenna with a novel microstrip‐compatible feed is presented. The new feed structure makes E‐shaped patch antennas more suitable for integration with microstrip circuits. It is demonstrated by designing and testing an antenna with a height of 3.3 mm and a return‐loss bandwidth of 5.03–6.12 GHz. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 111–112, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20223
Resistance training exercise and creatine in patients with Charcot–Marie–Tooth disease
Authors: Chetlin Robert D. , Gutmann Laurie , Tarnopolsky Mark A. , Ullrich Irma H. , Yeater Rachel A.
Published: May 2004

Resistance exercise and creatine supplementation independently improve strength and function in patients with certain neuromuscular diseases. The purpose of this study was to examine the effects of resistance training with and without creatine supplementation on muscle, strength, and function in patients with Charcot–Marie–Tooth (CMT) disease. Twenty patients with CMT consumed 5 g/day creatine or placebo while participating in resistance training for 12 weeks. Energy metabolites, muscle fiber type and size, strength, and timed activities of daily living were measured before and after training. There were no differences between creatine or placebo groups for any outcome. For the groups combined, exercise training increased type I muscle fiber diameter (48.2 ± 14.2 μm vs. 55.4 ± 14.8 μm), strength, and activities of daily living (ADL) times. Thus, patients respond to resistance training with muscle fiber adaptations, and improvements in strength and function. Creatine was not beneficial. © 2004 Wiley Periodicals, Inc. Muscle Nerve 30: 69–76, 2004
Array‐based comparative genomic hybridization for the detection of DNA sequence copy number changes in Barrett's adenocarcinoma
Authors: Albrecht Bettina , Hausmann Michael , Zitzelsberger Horst , Stein Hubert , Siewert Jörg Rüdiger , Hopt Ulrich , Langer Rupert , Höfler Heinz , Werner Martin , Walch Axel
Published: May 2004

Array‐based comparative genomic hybridization (aCGH) allows the identification of DNA sequence copy number changes at high resolution by co‐hybridizing differentially labelled test and control DNAs to a micro‐array of genomic clones. The present study has analysed a series of 23 formalin‐fixed, paraffin wax‐embedded tissue samples of Barrett's adenocarcinoma (BCA, n = 18) and non‐neoplastic squamous oesophageal (n = 2) and gastric cardia mucosa (n = 3) by aCGH. The micro‐arrays used contained 287 genomic targets covering oncogenes, tumour suppressor genes, and DNA sequences localized within chromosomal regions previously reported to be altered in BCA. DNA sequence copy number changes for a panel of approximately 50 genes were identified, most of which have not been previously described in BCA. DNA sequence copy number gains (mean 41 ± 25/BCA) were more frequent than DNA sequence copy number losses (mean 20 ± 15/BCA). The highest frequencies for DNA sequence copy number gains were detected for SNRPN (61%); GNLY (44%); NME1 (44%); DDX15, ABCB1 (MDR), ATM, LAMA3, MYBL2, ZNF217, and TNFRSF6B (39% each); and MSH2, TERC, SERPINE1, AFM137XA11, IGF1R, and PTPN1 (33% each). DNA sequence copy number losses were identified for PDGFB (44%); D17S125 (39%); AKT3 (28%); and RASSFI, FHIT, CDKN2A (p16), and SAS (CDK4) (28% each). In all non‐neoplastic tissue samples of squamous oesophageal and gastric cardia mucosa, the measured mean ratios were 1.00 (squamous oesophageal mucosa) or 1.01 (gastric mucosa), indicating that no DNA sequence copy number chances were present. For validation, the DNA sequence copy number changes of selected clones (SNRPN, CMYC, HER2, ZNF217) detected by aCGH were confirmed by fluorescence in situ hybridization (FISH). These data show the sensitivity of aCGH for the identification of DNA sequence copy number changes at high resolution in BCA. The newly identified genes may include so far unknown biomarkers in BCA and are therefore a starting point for further studies elucidating their possible role in Barrett's carcinogenesis. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Fetal serum ß2‐microglobulin and cystatin C in the prediction of post‐natal renal function in bilateral hypoplasia and hyperechogenic enlarged kidneys
Authors: Muller Françoise , Dreux Sophie , Audibert François , Chabaud Jean‐Jacques , Rousseau Thierry , D'Hervé Dominique , Dumez Yves , Ngo Sandrine , Gubler Marie‐Claire , Dommergues Marc
Published: May 2004

Objectives

To evaluate fetal serum ß2‐microglobulin and cystatin C in the prediction of post‐natal renal function in bilateral hypoplasia and hyperechogenic enlarged kidneys. Predicting post‐natal renal function is crucial to the prenatal evaluation of fetal nephropathies. Prenatal ultrasound can identify terminal renal failure, but is not sensitive enough to identify infants whose post‐natal renal function will be impaired. Fetal serum ß2‐microglobulin and cystatin C are potential predictors of post‐natal renal function.

Methods

Fifty‐four prenatally diagnosed cases of bilateral nephropathy were retrospectively reviewed. Final diagnosis was established using histological or post‐natal findings: renal hypoplasia (n = 7), cystic dysplasia (n = 9), autosomal dominant polycystic kidney disease (ADPKD; n = 8) or autosomal recessive polycystic kidney disease (ARPKD; n = 22) and transient sonographic abnormalities (n = 8). Fetal serum ß2‐microglobulin and cystatin C were assayed respectively in 54 and 38 cases. The prognostic value of these markers was assessed in terms of the post‐natal outcome.

Results

In bilateral kidney hypoplasia and cystic dysplasia, ß2‐microglobulin and cystatin C were significantly (p < 0.0001 and p < 0.02 respectively) higher than in the normal control group. In hyperechogenic fetal kidneys (ARPKD, ADPKD and transient sonographic abnormalities), these markers were not different from controls. However, whereas normal values cannot exclude renal failure, abnormal values predict post‐natal renal failure.

Conclusions

In bilateral renal hypoplasia and dysplasia, fetal serum ß2‐microglobulin and cystatin C are good markers for post‐natal renal function. However, in bilateral renal hyperechogenic enlargement, abnormal values are associated with poor post‐natal renal function, but normal values cannot preclude renal failure. Copyright © 2004 John Wiley & Sons, Ltd.
A comparison of the impact of screen‐positive results obtained from ultrasound and biochemical screening for Down syndrome in the first trimester: a pilot study
Authors: Weinans Martin J. N. , Kooij Loes , Müller Moira A. , Bilardo Katia M. , van Lith Jan M. M. , Tymstra Tjeerd
Published: May 2004

Objective

To compare the experiences of women who received a screen‐positive test result for Down syndrome after nuchal translucency screening or after biochemical screening in the first trimester of pregnancy in the Netherlands.

Method

Semi‐quantitative questionnaires were sent to 40 women with a screen‐positive test result for Down syndrome in the first trimester of pregnancy: 20 had undergone nuchal translucency screening (NT group) and 20 had undergone serum screening (PAPP‐A and free beta‐hCG) (SS group). In all the cases, chorionic villus sampling (CVS) had not revealed any chromosomal abnormalities.

Results

The major reason for undergoing the screening test in both groups of women was to be more reassured about the health of the baby. In the NT group, 5 out of the 20 women stated that they had suddenly been confronted with the NT measurement during the ultrasound examination without even being asked, or had been caught by surprise about the possibility. Together with two other women, they felt that at that stage they had been insufficiently informed about what the test meant. In the SS group, two women also held this opinion. In 10 out of the 20 women in the SS group, the positive‐screening result had caused (a great deal of) anxiety. In the NT group, this proportion was as high as 18 out of the 20. Six of the women in the NT group mentioned that ‘seeing the baby’ had been an important factor in their decision to undergo CVS. Even after a favourable result of CVS, a proportion of the pregnant women were still feeling anxious about the health of their baby (5 women in the SS group and 12 in the NT group). Nevertheless, a large proportion of the women in both groups was pleased that they had undergone the screening test. Only a few of them stated that they would not choose the same screening test again in a future pregnancy.

Conclusions

An unfavourable screening result after NT screening appeared to have a greater impact than an unfavourable result after serum screening. This might partly be explained by the ultrasound examination visualising the increased risk during NT screening. An additional important role may have been played by the fact that an abnormal NT screening result implies an increased risk of other disorders besides Down syndrome, which the women should be informed about beforehand. Several factors place special demands on the counselling prior to NT screening. Copyright © 2004 John Wiley & Sons, Ltd.
Buried contact solar cells with innovative rear localised contacts
Authors: Ho Anita Wing Yi , Wenham Stuart R.
Published: May 2004

A new rear contacting scheme using low‐temperature processes to form localised contacts without the use of photolithography has been developed. It uses randomly nucleated, aluminium‐induced, localised regions of solid phase epitaxial growth ofp+silicon onto the rear surface of a wafer through a thick rear surface passivating oxide. This rear contacting technique has been applied on solar cells with front buried contacts and results have shown that a suitable ohmic contact to the rear can be formed through oxide as thick as 3000 Å and using only low temperature sintering below the eutectic temperature of silicon and aluminium. This low‐temperature sintering avoids the destruction of the interfacial oxide which has been shown to provide good surface passivation for the rear of the solar cells. Microscopic images indicate the possibility of formingp+rear contacts with aluminium‐induced crystallisation, but without requiring any additional deposition of silicon. The source of silicon for the latter appears to be from the reduction of the silicon dioxide by the aluminium. Copyright © 2004 John Wiley & Sons, Ltd.
System Failure Analysis Through Counters of Petri Net Models
Authors: Adamyan Angela , He David
Published: May 2004

Petri nets are a powerful technique widely used in the modeling and analysis of complex manufacturing systems and processes. Due to their capability in modeling the dynamics of the systems, Petri nets have been combined with fault tree analysis techniques to determine the average rate of occurrence of system failures. Current methods in combining Petri nets with fault trees for system failure analysis compute the average rate of occurrence of system failures by tracking the markings of the Petri net models. The limitations of these methods are that tracking the markings of a Petri net represented by a reachability tree can be very complicated as the size of the system grows. Therefore, these methods offer less flexibility in analyzing sequential failures in the system. To overcome the limitations of the current methods in applying Petri nets for system failure assessment, this paper expands and extends the concept of counters used in Petri net simulation to perform the failure and reliability analysis of complex systems. The presented method allows the system failures to be modeled using general Petri nets with inhibitor arcs and loops, which employs fewer variables than existing marking‐based methods and substantially accelerates the computations. It can be applied to real system failure analysis where basic events can have different failure rates. Copyright © 2003 John Wiley & Sons, Ltd.
Lane recognition system based on the high‐speed pattern matching method
Authors: Ninomiya Yoshiki , Takahashi Arata , Ohta Mitsuhiko
Published: May 2004

Applications of lane recognition using an on‐board camera in the real world require image recognition technology that is both fast and robust. The authors propose a method that takes structure matching as a search problem for optimal patterns and then uses a voting approach for discrete template patterns as a method for pattern matching in this kind of image recognition technology. The authors implement their proposed method as an on‐board device for lane recognition, then set it up in pipelined hardware, and confirm that it can work in real time. In addition, the results of comparing their method with a conventional lane recognition method using 1000 scenes of images of highways in the rain, a subject used for lane recognition, confirm that their method makes few errors and is robust. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(8): 45–53, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10591
Analysis of pilot and early phase studies with small sample sizes
Authors: Shih Weichung Joseph , Ohman‐Strickland Pamela A. , Lin Yong
Published: May 2004

The need for statistical methodologies for analysing a small size study, such as a pilot or so‐called ‘proof of concept’ study, has not been paid much attention in the past. Recently the Institute of Medicine (IOM) formed a committee and held a workshop to discuss methodologies for conducting clinical trials with small number participants. In this paper we argue that the hypothesis of treatment effect in a small pilot study should be set up to test whetheranyindividual subject has an effect rather than whether the group mean or median has shifted as often done for large, confirmatory clinical trials. Based on this paradigm we propose multiple test procedures as one option when individuals have enough observations, and a mixture‐distribution approach when individuals have one or more observations. The latter approach may be used in either a one‐ or two‐group setting, and is our focus in this paper. We present the likelihood ratio tests for the mixture models. Examples are given to demonstrate the methods. Copyright © 2004 John Wiley & Sons, Ltd.
Sea‐ice change and its connection with climate change in the Arctic in CMIP2 simulations
Authors: Hu Zeng‐Zhen , Kuzmina Svetlana I. , Bengtsson Lennart , Holland David M.
Published: May 2004

In this work, we analyze the two‐dimensional distribution of mean and intermodel spread of Arctic sea ice and climate change at the time of CO2 doubling and their connection using the simulations from the second phase of the Coupled Model Intercomparison Project (CMIP2). Arctic surface warming at the time of CO2 doubling is found to be not evenly distributed and ranges from 1° to 5°C. The intermodel spread is pronounced in the Arctic Ocean, particularly in the Barents Sea. Reduction of sea‐ice thickness (SIT) is in the range 0.3–1.8 m and mainly appears in the Greenland‐Barents Seas. Meanwhile, sea‐ice concentrations (SIC) decrease more than 10% in most regions of the Arctic Ocean. The sensitivity of Arctic surface air temperature change with respect to sea‐ice area change is model‐dependent. For some models, the sensitivity is different even in different periods of the transient integration. Values of the sensitivity vary from −2.0 to −0.5°C/106 km2 for most CMIP2 models. A colder (warmer) Arctic climate may favor a higher (lower) sensitivity. The simulated mean and intermodel spread patterns of surface air temperature (SAT) change are similar to those of SIT and sea level pressure (SLP) changes. This implies that the mean and intermodel spread of projected Arctic climate change are influenced by the interaction between sea ice and the atmosphere. Both SIT and SIC are sensitive to the increase in greenhouse gas concentrations, and are connected with SAT and SLP changes in the Arctic. The average of all model simulations indicates that the north‐south SLP gradient and the mean westerly winds are enhanced by CO2 doubling. Finally, both the mean and intermodel spread patterns show considerable differences between models with and without flux adjustment in some regions.
Characterization of the surface properties of epoxy‐type models used for multiphase flow studies in fractured media and creation of a new model
Authors: Bergslien Elisa , Fountain John , Giese Rossman
Published: May 2004

Epoxy models have been used as analogs for fractured rock surfaces in many laboratory investigations of multiphase flow processes. However, there is no agreement on how well or poorly such an analog replicates the surface chemistry of geologic materials, nor is there a satisfactory analysis of the surface properties of epoxy. This paper addresses the issue of accurately characterizing the surface chemistry of a typical epoxy used in laboratory multiphase flow studies and comparing that surface to a polystyrene surface and a radio frequency glow discharge treated polystyrene surface. Surface properties were determined using direct contact angle measurements of polar and apolar liquids on flat test samples. The epoxy was determined to have surface properties as follows: γ = 62.3, γLW = 39, γAB = 23.3, γ⊕ = 0, and γ = 23.3 mJ/m2, where γ is the total surface tension of the solid, γLW is the Lifshitz‐van der Waals (LW) surface tension component, γAB is the Lewis acid base (AB) surface tension component, γ is the electron‐donor (negative) parameter, and γ⊕ is the electron‐acceptor (positive) parameter. Values of γ < 27.9 mJ/m2 indicate a hydrophobic surface, which means that epoxy is not a good analog for most geologic materials. This study also explores the use of radio frequency glow discharge plasma to add hydroxyl functionality to polymer surfaces producing a material with alterable surface properties and the same optical and casting properties as epoxy. Using this method, the degree of alteration of the surface chemistry of polymer fracture models can be controlled, allowing the creation of models with a variety of different wettabilities. The resultant models were found to be durable, long lasting, and a potentially very useful alternative to the more typical epoxy models.
Machine failure forewarning via phase-space dissimilarity measures
Authors: Hively L. M. , Protopopescu V. A.
Published: May 2004

We present a model-independent, data-driven approach to quantify dynamical changes in nonlinear, possibly chaotic, processes with application to machine failure forewarning. From time-windowed data sets, we use time-delay phase-space reconstruction to obtain a discrete form of the invariant distribution function on the attractor. Condition change in the system’s dynamic is quantified by dissimilarity measures of the difference between the test case and baseline distribution functions. We analyze time-serial mechanical (vibration) power data from several large motor-driven systems with accelerated failures and seeded faults. The phase-space dissimilarity measures show a higher consistency and discriminating power than traditional statistical and nonlinear measures, which warrants their use for timely forewarning of equipment failure.
Spiral dynamics of pulsating methane–oxygen flames on a circular burner
Authors: Robbins Kay , Gorman Michael , Bowers Jill , Brockman Robert
Published: May 2004

A premixed flame stabilized on a circular porous plug burner produces a uniform, steady luminous flame front. Throughout much of the parameter range hydrocarbon–oxygen mixtures form spiral-shaped fronts. In methane–oxygen flames at low pressure, the flame exhibits a sequence of states as a control parameter is decreased. These states include periodic rotation of a spiral front; precession of the spiral front in a direction opposite to its rotation, corresponding to doubly periodic petals-out meandering; and nonperiodic states with intermittent jumps associated with linear excursions of the tip, which occur after the spiral front has reached the boundary of the circular burner. We use Karhunen–Loeve (KL) analysis to find the coefficients of the dominant KL spatial eigenfunctions. Their phase space portraits and power spectra provide a description of the dynamics as flow rates are reduced and the system destabilizes. We discuss how these experimental results relate to previous theoretical studies that assume Euclidean symmetry for the experimental configuration.
Fast exponential fitting algorithm for real-time instrumental use
Authors: Halmer Daniel , von Basum Golo , Hering Peter , Mürtz Manfred
Published: May 2004

We report on a very fast fitting algorithm for single exponential functions which is based on the method of successive integration. The algorithm corrects the systematic error of trapezoidal integration. The new algorithm needs only 150 μs for a dataset of 1536 points and is around 700 times faster than the nonlinear Levenberg–Marquardt fit provided by LABVIEW. This makes it suitable for real-time instrumental use. Beside the better time resolution, the acceleration allows more averaging, which leads to higher precision. In our experiment instrumental sensitivity was improved by a factor of 3.7.
Multifunctional sensor system for high-throughput primary, secondary, and tertiary screening of combinatorial materials
Authors: Potyrailo Radislav A. , Morris William G. , Wroczynski Ronald J.
Published: May 2004

A modular multifunctional acoustic wave thickness shear mode sensor system has been designed and implemented for the rapid characterization of materials. The sensors are arranged as a 6×4 array and are compatible with available 24-well plates for manipulation with standard robotic equipment. The sensor system has two types of sensor enclosures including a gas-flowthough cell for studies of vapor-sorption properties and weathering of materials and a platform for immersion of sensors into 24-well plate arrays for studies of materials solubility. In addition, the sensor array design can be operated remotely from the rest of electronic components to decouple the environment of sensor array exposure (e.g., high temperature, pressure, chemicals). This sensor system has been used to screen sensor materials to emphasize (1) the magnitude of sensor response to the parameter of interest; (2) sensor specificity against environmental interferences; and (3) long-term stability. This work for the first time addresses all three aspects in sensor material development with a dedicated three-level high-throughput screening approach. The primary screen is the discovery screen where materials are exposed to a single analyte concentration. The secondary screen is the focused evaluation where the best subset of these materials is exposed to analytes and interference. The tertiary screen involves evaluation of material performance under conditions that mimic the long-term application. This approach can efficiently screen sensor materials not only for immediate performance but also for long-term stability thus providing significant saving of time in sensor development.
Period-adding bifurcations and chaos in a bubble column
Authors: Piassi Viviane S. M. , Tufaile Alberto , Sartorelli José Carlos
Published: May 2004

We obtained period-adding bifurcations in a bubble formation experiment. Using the air flow rate as the control parameter in this experiment, the bubble emission from the nozzle in a viscous fluid undergoes from single bubbling to a sequence of periodic bifurcations of k to k+1 periods, occasionally interspersed with some chaotic regions. Our main assumption is that this period-adding bifurcation in bubble formation depends on flow rate variations in the chamber under the nozzle. This assumption was experimentally tested by placing a tube between the air reservoir and the chamber under the nozzle in the bubble column experiment. By increasing the tube length, more period-adding bifurcations were observed. We associated two main types of bubble growth to the flow rate fluctuations inside the chamber for different bubbling regimes. We also studied the properties of piecewise nonlinear maps obtained from the experimental reconstructed attractors, and we concluded that this experiment is a spatially extended system.
Monte Carlo simulation for the formation of a mixed crystal from two solids in contact
Authors: Yinnon C. A. , Buch V. , Devlin J. P.
Published: May 2004

The study focuses on nucleation and growth of a binary mixed crystal phase from two pure crystals in contact. Monte Carlo simulations of this process are conducted, with the dynamics proceeding via activated atom–vacancy exchanges. Intermolecular interactions, ranging up to next-nearest neighbors, are of size typical of hydrogen bonded systems. The process is driven by the formation of strong AB bonds at the expense of weaker AA and BB bonds. In the resulting model, the material is channeled and transported through the mixed phase crust along antiphase boundaries. The flow of molecules through the channels is directed, due to molecular energy lowering via gradual acquisition of an increasing number of nearest neighbors of the second species. On the other hand, defect motion is quasirandom. The model accounts partially for the t1/α (α>3) time dependence observed for conversion of nanoparticles of HBr dihydrate to monhydrate, by exposure to acid adsorbate.
Femtosecond primary events in bacteriorhodopsin and its retinal modified analogs: Revision of commonly accepted interpretation of electronic spectra of transient intermediates in the bacteriorhodopsin photocycle
Authors: Abramczyk Halina
Published: May 2004

Femtosecond primary events in bacteriorhodopsin (BR) and its retinal modified analogs are discussed. Ultrafast time resolved electronic spectra of the primary intermediates induced in the BR photocycle are discussed along with spectral and kinetic inconsistencies of the previous models proposed in the literature. The theoretical model proposed in this paper based on vibrational coupling between the electronic transition of the chromophore and intramolecular vibrational modes allows us to calculate the equilibrium electronic absorption band shape and the hole burning profiles. The model is able to rationalize the complex pattern of behavior for the primary events in BR and explain the origin of the apparent inconsistencies between the experiment and the previous theoretical models. The model presented in the paper is based on the anharmonic coupling assumption in the adiabatic approximation using the canonical transformation method for diagonalization of the vibrational Hamiltonian instead of the commonly used perturbation theory. The electronic transition occurs between the Born–Oppenheimer potential energy surfaces with the electron involved in the transition being coupled to the intramolecular vibrational modes of the molecule (chromophore). The relaxation of the excited state occurs by indirect damping (dephasing) mechanisms. The indirect dephasing is governed by the time evolution of the anharmonic coupling constant driven by the resonance energy exchange between the intramolecular vibrational mode and the bath. The coupling with the intramolecular vibrational modes results in the Franck–Condon progression of bands that are broadened due to the vibrational dephasing mechanisms. The electronic absorption line shape has been calculated based on the linear response theory whereas the third order nonlinear response functions have been used to analyze the hole burning profiles obtained from the pump–probe time-resolved measurements. The theoretical treatment proposed in this paper provides a basis for a substantial revision of the commonly accepted interpretation of the primary events in the BR photocycle that exists in the literature.
Glassy phases in random heteropolymers with correlated sequences
Authors: Müller M. , Mézard M. , Montanari A.
Published: May 2004

We develop an analytic approach for the study of lattice heteropolymers and apply it to copolymers with correlated Markovian sequences. According to our analysis, heteropolymers present three different dense phases depending upon the temperature, the nature of the monomer interactions, and the sequence correlations: (i) a liquid phase, (ii) a “soft glass” phase, and (iii) a “frozen glass” phase. The presence of the intermediate “soft glass” phase is predicted, for instance, in the case of polyampholytes with sequences that favor the alternation of monomers. Our approach is based on the cavity method, a refined Bethe–Peierls approximation adapted to frustrated systems. It amounts to a mean-field treatment in which the nearest-neighbor correlations, which are crucial in the dense phases of heteropolymers, are handled exactly. This approach is powerful and versatile; it can be improved systematically and generalized to other polymeric systems.