bluuebunny/crossref_metadata_2025 huggingface dataset:
X-ray diffraction analyses of titanium coatings produced by electron beam evaporation in neon and argon inert gases
Authors: Avelar-Batista J. C. , Wilson A. D. , Davison A. , Matthews A. , Fancey K. S.
Published: September 2003

Titanium coatings were deposited on glass substrates by electron beam evaporation in both argon and neon at pressures from 0.33 to 2.00 Pa and also under vacuum (4×10−4 Pa) conditions. X-ray diffraction was used to assess the effect of gas pressure on coating preferred orientation, microstrain, and crystallite size. The addition of either argon or neon increased the occurrence of other planes lying parallel to the surface in addition to the major (0 0 0 2) orientation obtained during vacuum evaporation. The microstrain in the films increased with crystallite size. A very small crystallite size was obtained from the vacuum-evaporated coating. In comparison with vacuum evaporation, however, crystallite size was observed to increase significantly with the introduction of either inert gas at 0.33 Pa and then reduce with increasing pressure. It is inferred that the change in crystallite size arises from metal cluster formation in the gas phase; larger clusters are suggested to form in argon.
Progress in electronic materials characterization
Authors: Holloway Paul H.
Published: September 2003

Progress in characterization of electronic materials over the past 50 years has been illustrated by selected examples of determination of the atomistic reconstruction and formation of electronic states at surfaces and interfaces of semiconductors using surface sensitive characterization techniques. Similar techniques have been used to characterize reactions at interfaces and determine the mechanisms by which charge carrier transport is changed from that controlled by Schottky rectifying to contacts with ohmic characteristics. The use of seconday ion mass spectrometry to measure dopant profiles over dimensions <10 nm below the surface is illustrated, and the use of optical characterization techniques for real time control of semiconductor growth was also illustrated. Finally, areas of future development of characterization techniques for electronic materials were discussed.
Electronic materials theory: Interfaces and defects
Authors: Van de Walle Chris G.
Published: September 2003

An overview of developments in materials theory is presented, with an emphasis on first-principles calculations. Examples are given from the fields of heterojunction interfaces and point defects in semiconductors. Predictive theories of materials are shown to be increasingly important for understanding but also designing materials and structures.
Measurement of vacuum; 1950–2003
Authors: Redhead P. A.
Published: September 2003

The major developments in the measurement of vacuum since the Bayard–Alpert gauge was invented in 1950 are reviewed; the American Vacuum Society was started three years later in 1953. These developments include (a) the improvement in understanding the processes causing limitations of the lowest measurable pressures (both total and partial), (b) the development of gauges, residual gas analyzers, and optical methods of pressure measurement to reduce these limitations, (c) the introduction of room-temperature electron sources (Spindt cathodes) to replace thermionic cathodes, and (d) the development of the spinning rotor gauge as a secondary standard.
Development of ultrahigh and extreme high vacuum technology for physics research
Authors: Dylla H. F.
Published: September 2003

Over the last 50 years increasingly large and more sophisticated devices have been designed and put into operation for the study of particle and nuclear physics, magnetic confinement of high temperature plasmas for thermonuclear fusion research, and gravity wave observatories based on laser interferometers. The evolution of these devices has generated many developments in ultrahigh and extreme high vacuum technology that were required for these devices to meet their operational goals. The technologies that were developed included unique ultrahigh vacuum vessel structures, ultrahigh vacuum compatible materials, surface conditioning techniques, specialized vacuum pumps, and vacuum diagnostics. Associated with these technological developments are scientific advancements in the understanding of outgassing limits of UHV-compatible materials and particle-induced desorption effects.
Electronic materials and processing: 1979–2003
Authors: Brillson Leonard J.
Published: September 2003

This foreword introduces the Electronic Materials and Processing Division section of the fiftieth anniversary issue of the Journal of Vacuum Science and Technology. This section provides an overview of the four major areas of achievement that electronic materials and processing research has brought to the American Vacuum Society and the world of science and technology at large. The four papers that follow illuminate these achievements, their impact on physical science-based technology over half a century, and the promise of continuing discovery and innovation into the future.
Thin film deposition with physical vapor deposition and related technologies
Authors: Rossnagel S. M.
Published: September 2003

The properties of thin films depend critically on how they are made. For the most part, thin films are assembled in ways very different from the production of bulk materials. Thin films are usually deposited on existing, bulk surfaces using techniques based on atomic or molecular scale physics and chemistry. Physical vapor deposition (PVD) of thin films relies on the removal of atoms from a solid or a liquid by energetic means, and the subsequent deposition of those atoms on a nearby surface. Variations of PVD processes include thermal evaporation, physical sputtering, laser ablation, and arc-based emission. Additional modifications to physical sputter deposition have been made to enhance the chemical and/or structural nature of the deposited films. These modifications include reactive sputter deposition, the unbalanced magnetron, collimated and ionized sputter deposition. Each of these systems and techniques will be described as well as some of the current day applications of the films produced.
Plasma science and technology: 50 years of progress
Authors: Cecchi J. L. , Cecchi L. M.
Published: September 2003

During the first 50 years of the American Vacuum Society (1953–2003), technology has advanced greatly. But the most impressive and conspicuous advance has been in computational power, due to the exponential increase in computing power at an exponentially decreasing cost per function. Many of our readers will remember the “Macro-Mechanical System” called a slide rule that was symbolic of engineers and scientists in the 1950s and 1960s. From the slide rule of the past to today’s desktop and notebook computers, possessing speed, storage, and power capability that dwarf the mainframes of the recent past, what a transformation!
Metrology of 1–10 nm thick CNx films: Thickness, density, and surface roughness measurements
Authors: Li Dejun , Chen Yanfeng , Chung Yip-Wah , Freire Fernando Lazaro
Published: September 2003

Ultrathin nitrogenated carbon (CNx) films were synthesized using pulsed dc magnetron sputtering. The influence of substrate tilt angle and rotation speed on surface roughness was explored. Atomic force microscopy studies showed that the smoothest films were obtained at substrate tilt of 45° and rotation speed 20–25 rpm, corresponding to 2–3 rotations per deposited atomic layer. The root-mean-square surface roughness under these optimum conditions is ∼0.3 nm when sampled over 20×20 μm2 areas, increasing to ∼0.4 nm when sampled over ∼0.05×3 cm2 using x-ray reflectivity measurements. In addition, x-ray reflectivity measurements showed that the mass density of these CNx films is ∼2.0 gm/cc, independent of film thickness from ∼1 to 10 nm, consistent with ion beam analysis.
Structural and electrical characteristics of the interfacial layer of ultrathin ZrO2 films on partially strain compensated Si0.69Ge0.3C0.01 layers
Authors: Mahapatra R. , Maikap S. , Lee Je-Hun , Kar G. S. , Dhar A. , Kim Doh-Y. , Bhattacharya D. , Ray S. K.
Published: September 2003

The structural characteristics of ZrO2 films along with the interfacial layers deposited on partially strain compensated Si0.69Ge0.3C0.01/Si heterostructure have been investigated using x-ray diffraction (XRD), high resolution transmission electron microscopy (TEM), time-of-flight secondary ion mass spectroscopy (SIMS), and x-ray photoelectron spectroscopy (XPS) measurements. XRD spectra show the films to be polycrystalline with both monoclinic and tetragonal phases. The ZrO2 film with physical thickness of ∼8.5 nm and an amorphous interfacial layer with a physical thickness of ∼3.6 nm have been observed by high resolution TEM, SIMS and XPS. SIMS and XPS analyses show the formation of an amorphous Zr–germano–silicate interfacial layer between the deposited oxide and SiGeC films. The electrical properties in terms of capacitance–voltage (C–V), conductance–voltage, current density–voltage, and gate voltage shift (ΔVg) under a constant current stressing have been studied using a metal–insulator–semiconductor (MIS) structure. A dielectric constant of 17.5 for ZrO2 and 7.0 for interfacial Zr–Ge–silicate layer have been calculated from the high frequency C–V characteristics. These dielectrics show an equivalent oxide thickness (EOT) as low as 1.9 nm for ZrO2 and 2.0 nm for the interfacial silicate layer. The MIS capacitor shows an extremely low leakage current density of ∼9×10−8 A/cm2 at a gate voltage of −1.0 V, breakdown field of 7 MV/cm based on EOT as the length scale, and moderate interface state density (Dit) of 4.8×1011 cm−2 eV−1 for ZrO2 with interfacial layer. The Zr–Ge–silicate interfacial layer separately shows a low leakage current density of 3×10−2 A/cm2 at Vg of −1 V and Dit of 1×1012 cm−2 eV−1. Significant improvements in the charge trapping properties under Fowler–Nordheim constant current stressing in both ZrO2 with the interfacial layer and Zr–Ge–silicate layers have been observed.
AJP Reviewers
Authors: Tobochnik Jan , Gould Harvey
Published: September 2003

Below is a listing of the 727 individuals who have reviewed manuscripts for the American Journal of Physics from June 1, 2002 to July 1, 2003. If you have reviewed for AJP during this time and are not on the list, we apologize and hope that you will let us know so that we can correct our records. If you are interested in reviewing for AJP and have not done so recently, please fill out the questionnaire at www.kzoo.edu/ajp/referees.html. The thoughtful and expert advice offered by the reviewers is essential for maintaining the quality of the journal. On behalf of all AJP authors and readers, we thank those listed below who have served as reviewers.
Preparation of benzocyclobutenols by low temperature reaction of ketone enolates with benzynes
Authors: Tripathy Sasmita , Reddy Ranga , Durst Tony
Published: September 2003

The reaction of benzynes, generated from halobenzenes with lithium tetramethylpipiperide (LTMP) at 40 to 78 °C, with ketone enolates affords benzocyclobutenols in fair to good yields.Key words: benzyne, ketone enolates, anthracenes, benzocyclobutenol, alkoxides.
Reactions of dimethoxycarbene with thiocarbonyl compounds
Authors: Dawid Malgorzata , Mloston Grzegorz , Reid Darren L , Warkentin John
Published: September 2003

A diverse sample of thiocarbonyl compounds were examined to determine what the ultimate stable products are of their reactions with dimethoxycarbene. Those ultimate products can be significantly different for an oxyphosphinyl dithioformate, methyl dithiobenzoate, O-methyl thiobenzoate, and dimethyl xanthate. Key words: dimethoxycarbene, thiocarbonyl compounds, 2,5-dihydro-2,2-dimethoxy-5,5-dimethyl-1,3,4-oxadiazole.
Equilibrium Concepts for Social Interaction Models
Authors: Blume Lawrence , Durlauf Steven
Published: September 2003

This paper describes the relationship between two different binary choice social interaction models. The Brock and Durlauf (2001) model is essentially a static Nash equilibrium model with random utility preferences. In the Blume (2003) model is a population game model similar to Blume (1993), Kandori, Mailath and Rob (1993) and Young (1993). We show that the equilibria of the Brock–Durlauf model are steady states of a differential equation which is a deterministic approximation of the sample-path behavior of Blume's model. Moreover, the limit distribution of this model clusters around a subset of the steady states when the population is large.
The Cortical Ancestry of Oligodendrocytes: Common Principles and Novel Features
Authors: Noble M. , Arhin A. , Gass D. , Mayer-Pröschel M.
Published: September 2003

Studies on the development of cortical oligodendrocytes indicate that although general principles that apply to other parts of the CNS are applicable, there are important differences that appear to be critical to the analysis of this lineage in the cortex. Herein, we review previous studies demonstrating that oligodendrocyte-type-2 astrocyte progenitor cells (or oligodendrocyte precursor cells; aka O-2A/OPCs) of the developing postnatal cortex exhibit a striking cell-intrinsic bias towards undergoing prolonged self-renewal in the relative absence of oligodendrocyte generation [Power et al., Dev Biol 2002;245: 362–375]. This phenotype is quite distinct from that observed in comparable cells isolated from the optic tract. This predilection for self-renewal is associated with a lessened response to inducers of oligodendrocyte generation and of possible mechanistic importance in regards to these other properties. We also review studies on stem/progenitor cells isolated from the embryonic cortex that are able to generate oligodendrocytes. As for the studies on O-2A/OPCs, important differences also distinguish these early cells from those studied in other CNS regions in their response to signaling molecules and expression of the Dlx family of transcriptional regulators [He et al., J Neurosci 2001;21:8854–8862; Yung et al., Proc Natl Acad Sci USA 2002;99:16273–16278]. We also present new data on clonal analysis of A2B5+ precursor cells isolated from the E13.5 cortex, demonstrating that this tissue appears to contain a cell similar in properties to the tripotential glial-restricted precursor cell that has been isolated from embryonic spinal cord [Rao et al., Proc Natl Acad Sci USA 1998;95:3996–4001]. Moreover, the A2B5+ precursor cells isolated from embryonic cortex are much more heterogeneous than is seen in the spinal cord at this age, even to the point of including an A2B5/PSA-NCAM double-positive cell that can generate neurons.
Dental Health Knowledge, Attitudes and Behaviour among Students at the Kuwait University Health Sciences Centre
Authors: Al-Hussaini R. , Al-Kandari M. , Hamadi T. , Al-Mutawa A. , Honkala S. , Memon A.
Published: September 2003

Objective: The aim of the study was to determine the extent of dental health knowledge among students at the Kuwait University Health Sciences Centre (HSC), as well as their attitudes toward dental health and their oral hygiene habits. Methods: A structured questionnaire was distributed to 450 of the 800 students enrolled in 3 faculties of the HSC from March to April 2000. The questionnaire was completed anonymously by the students. Results: Four hundred and ten students (91.1%) completed the questionnaire. Of these, 64.6% believed that the main cause of tooth decay was ‘not brushing properly’. Only 19.3% of the students believed that sugar could cause dental decay. Half of the students did not know if sugar-free drinks are harmful to their teeth, and 29.5% did not know about any measures to prevent gums from bleeding. Self-assessment questions showed that 84.5% of the students were satisfied with their dental health. A large majority of the students (94.8%) brushed their teeth at least once a day. Female students brushed their teeth more frequently than male students, as did those students who had visited a dentist in the past 6–12 months and those who rated their dental health to be very good. The main reason given for a dental visit was toothache (70.0%). Coffee was consumed daily by 68.9% of students, 76.6% of whom added sugar to their coffee. Conclusions: The findings indicate that although most of the students at the HSC seem to be satisfied with their dental health, they did not have correct knowledge about the causes and prevention of dental diseases. In general, female students were more aware and concerned about dental health issues and more engaged in dental behaviour than male students.
Clinical Profiles and Outcomes of Acute Type B Aortic Dissection in the Current Era: Lessons From the International Registry of Aortic Dissection (IRAD)
Authors: Suzuki Toru , Mehta Rajendra H. , Ince Hüseyin , Nagai Ryozo , Sakomura Yasunari , Weber Frank , Sumiyoshi Tetsuya , Bossone Eduardo , Trimarchi Santi , Cooper Jeanna V. , Smith Dean E. , Isselbacher Eric M. , Eagle Kim A. , Nienaber Christoph A.
Published: September 2003

Background—

Clinical profiles and outcomes of patients with acute type B aortic dissection have not been evaluated in the current era.

Methods and Results—

Accordingly, we analyzed 384 patients (65±13 years, males 71%) with acute type B aortic dissection enrolled in the International Registry of Acute Aortic Dissection (IRAD). A majority of patients had hypertension and presented with acute chest/back pain. Only one-half showed abnormal findings on chest radiograph, and almost all patients had computerized tomography (CT), transesophageal echocardiography, magnetic resonance imaging (MRI), and/or aortogram to confirm the diagnosis. In-hospital mortality was 13% with most deaths occurring within the first week. Factors associated with increased in-hospital mortality on univariate analysis were hypotension/shock, widened mediastinum, periaortic hematoma, excessively dilated aorta (≥6 cm), in-hospital complications of coma/altered consciousness, mesenteric/limb ischemia, acute renal failure, and surgical management (all
P
<0.05). A risk prediction model with control for age and gender showed hypotension/shock (odds ratio [OR] 23.8,
P
<0.0001), absence of chest/back pain on presentation (OR 3.5,
P
=0.01), and branch vessel involvement (OR 2.9,
P
=0.02), collectively named ‘the deadly triad’ to be independent predictors of in-hospital death.

Conclusions—

Our study provides insight into current-day profiles and outcomes of acute type B aortic dissection. Factors associated with increased in-hospital mortality (“the deadly triad”) should be identified and taken into consideration for risk stratification and decision-making.
Topical VEGF Enhances Healing of Thoracic Aortic Anastomosis for Coarctation in a Rabbit Model
Authors: Seipelt Ralf G. , Backer Carl L. , Mavroudis Constantine , Stellmach Veronica , Seipelt Ingrid M. , Cornwell Mona , Hernandez Jose , Crawford Susan E.
Published: September 2003

Background—

Recurrent stenosis after extended end-to-end anastomosis for aortic coarctation is the primary indication for further interventions in children. Tension because of the extended resection and local arterial wall hypoxia are possible pathogenetic mechanisms. We hypothesized that (1) tension interferes with healing and (2) that vascular endothelial growth factor (VEGF), a hypoxia sensitive angiogenic inducer, may enhance healing of the vascular anastomosis.

Methods and Results—

In a model of coarctation repair, rabbits underwent thoracic aortic end-to-end anastomosis after transection (no-tension; n=15), resection of an aortic ring (tension; n=14) or resection and topical VEGF treatment (0.75 μg VEGF
165
; tension+VEGF; n=14). Gross and histologic characteristics of the aortic wall were assessed at 1 week, 1 and 2 months. In the tension only group at 1 month, the severity of vascular remodeling was increased with fibrosis and calcification compared with controls. At 2 months, this group also revealed more luminal stenosis (29% versus 19%;
P
<0.001). Exogenous VEGF resulted in significantly less fibrosis, calcification and chondroid metaplasia at 1 month (
P
<0.05) and luminal area was only reduced 3% at 2 months (
P
<0.001 versus tension group).

Conclusions—

In a rabbit model of coarctation repair, the addition of tension on the vascular anastomosis resulted in poor healing and luminal stenosis. Topical VEGF maintained luminal integrity by decreasing fibrosis and calcification. These findings suggest that topical VEGF may be a promising new strategy to enhance healing and improve the outcome of vascular anastomoses for coarctation of the aorta.
Long-Term Prognosis of Patients With Type B Aortic Intramural Hematoma
Authors: Kaji Shuichiro , Akasaka Takashi , Katayama Minako , Yamamuro Atsushi , Yamabe Kenji , Tamita Koichi , Akiyama Maki , Watanabe Nozomi , Tanemoto Kazuo , Morioka Shigefumi , Yoshida Kiyoshi
Published: September 2003

Background—

The long-term clinical course of patients with type B aortic intramural hematoma (IMH) and predictors for progression remains unknown. The difference of aortic pathology may have a different impact on clinical course compared with classic aortic dissection (AD). The purpose of this study was to investigate long-term clinical course and predictors of progression in patients with type B IMH.

Methods and Results—

Clinical data were compared retrospectively between 53 patients with acute type B IMH (IMH group) and 57 patients with acute type B AD (AD group). All patients were treated initially with medical therapy. Two patients in IMH group and 14 patients in AD group underwent surgical repair because of aortic enlargement. The in-hospital mortality rate in IMH group was significantly lower than that in AD group (0% and 14%,
P
=0.006). Mean follow-up periods were 53±43 months, which revealed 3 and 5 late deaths, respectively. Eleven patients with IMH showed progression (development of aortic dissection or aortic enlargement) in follow-up imaging study. The actuarial survival rates in IMH group were 100%, 97%, and 97% at 1, 2, and 5 years, which were significantly higher than those in AD group (83%, 79%, and 79%) (
P
=0.009). Multivariate analysis identified age >70 years and new appearance of an ulcerlike projection as the strongest predictors of progression in patients with IMH.

Conclusions—

Patients with type B IMH have better long-term prognosis than patients with AD. Older age and appearance of an ulcerlike projection are predictive for progression in patients with type B IMH.
Transfection With a Dominant-Negative Inhibitor of Monocyte Chemoattractant Protein-1 Gene Improves Cardiac Function After 6 Hours of Cold Preservation
Authors: Kajihara Noriyoshi , Morita Shigeki , Nishida Takahiro , Tatewaki Hideki , Eto Masataka , Egashira Kensuke , Yasui Hisataka
Published: September 2003

Background—

Monocyte chemoattractant protein-1 (MCP-1), a potent chemotactic factor for monocytes, is induced during ischemia-reperfusion. As monocytes might play an important causative role in reperfusion injury, we investigated if inhibition of monocyte activation could attenuate ischemia-reperfusion injury and thereby improve cardiac preservation. To inhibit monocyte activation, we transfected a dominant-negative inhibitor of MCP-1 (7ND) gene in an animal model.

Methods and Results—

We used an isolated rabbit heart preparation perfused with support-rabbit blood and transfected 7ND genes to skeletal muscle of the support rabbits (n=7) using electroporation technique; causing an elevation of serum 7ND level to 20±7 pg/mL at 5 days after transfection. Animals receiving empty plasmid served as controls (n=7). Five days after transfection, hearts from other rabbits were excised, stored in UW solution for 6hours, and perfused with blood from transfected support rabbits. The 7ND group showed better cardiac output (128.7±17.9 versus 81.6±19.8 mL/min;
P
<0.01), lower serum CK-MB levels (5.0±1.8 versus 11.1±2.9 ng/mL;
P
<0.01), lower serum IL-1β levels (257.2±23.2 versus 311.2±37.4pg/mL;
P
<0.05), and lower serum TNF-α levels (19.0±8.4 versus 35.1±13.0pg/mL;
P
<0.05). The numbers of infiltrating cells in myocardium were significantly reduced in the 7ND group.

Conclusions—

Inhibition of MCP-1 with 7ND gene transfection reduced cytokine activation, attenuated myocardial damage, and improved cardiac function after 6 hours of preservation. These results show that MCP-1 plays an important role in ischemia-reperfusion injury.
Predictors of Adverse Outcome and Transient Neurological Dysfuntion Following Surgical Treatment of Acute Type A Dissections
Authors: Ehrlich Marek P. , Schillinger Martin , Grabenwöger Martin , Kocher Alfred , Tschernko Edda M. , Simon Paul , Bohdjalian Arthur , Wolner Ernst
Published: September 2003

Predictors of adverse outcome after replacement of the ascending aorta with resection of the intimal tear and open distal anastomosis were analyzed in 167 patients (109 male, median age 56). Median hypothermic circulatory arrest (HCA) time was 30 minutes (range 12 to 113). Eighty-six patients (pts) had surgery within 24 hours and 81 within 72 hours of symptom onset. Thirty-seven pts had only ascending aortic replacement, 128 had hemiarch repair, and in 2 the entire arch was replaced. The aortic valve was replaced in 37 pts, resuspended in 116, and untouched in 14. Either death or permanent neurological dysfunction was considered an adverse outcome (AO). AO occurred in 30.5% (51/167) of patients overall. Multivariate analysis revealed that the only significant (
P
<0.05) independent preoperative predictor of AO was hemodynamic instability (OR 6.0). Transient neurological dysfunction (TND) occurred in 19 of 116 patients (16.4%). Significant predictors of TND were increasing age >60 (OR 3.4 and 7.0 in the second and third tertile as compared with the lowest tertile) and coronary heart disease (OR 3.4). Cumulative survival of patients (median follow-up 34 months) was 55% at 1, 49% at 5, and 44% at 8 years, indicating an excessive in-hospital mortality, but excellent long term outcome. Surgical treatment of acute type A dissections is still associated with a high incidence of adverse outcome, but results in excellent long-term survival. Earlier diagnosis, before the development of cardiac tamponade and hemodynamic compromise, is critical to improve the operative salvage rate.
Importance of Mitral Valve Repair Associated With Left Ventricular Reconstruction for Patients With Ischemic Cardiomyopathy: A Real-Time Three-Dimensional Echocardiographic Study
Authors: Qin Jian Xin , Shiota Takahiro , McCarthy Patrick M. , Asher Craig R. , Hail Melanie , Agler Deborah A. , Popović Zoran B. , Greenberg Neil L. , Smedira Nicholas G. , Starling Randall C. , Young James B. , Thomas James D.
Published: September 2003

Background—

Left ventricular (LV) reconstruction surgery leads to early improvement in LV function in ischemic cardiomyopathy (ICM) patients. This study was designed to evaluate the impact of mitral valve (MV) repair associated with LV reconstruction on LV function 1-year after surgery in ICM patients assessed by real-time 3-dimensional echocardiography (3DE).

Methods and Results—

Sixty ICM patients who underwent the combination surgery (LV reconstruction in 60, MV repair in 30, and revascularization in 52 patients) were studied. Real-time 3DE was performed and LV volumes were obtained at baseline, discharge, 6-month and ≥12-month follow-up. Reduction in end-diastolic volumes (EDV) by 29% and in end-systolic volumes by 38% were demonstrated immediately after surgery and remained at subsequent follow-up (
P
<0.0001). The LV ejection fraction significantly increased by about 10% at discharge and was maintained ≥12-month (
P
<0.0001). Although the LV volumes were significantly larger in patients with MV repair before surgery (EDV, 235±87 mL versus 193±67 mL,
P
<0.05), they were similar to LV volumes of the patients without MV repair at subsequent follow-ups. However, the EDV increased from 139±24 mL to 227±79 mL (
P
<0.01) in 7 patients with recurrent mitral regurgitation (MR). Improvement in New York Heart Association functional class occurred in 81% patients during late follow-up.

Conclusion—

Real-time 3DE demonstrates that LV reconstruction provides significant reduction in LV volumes and improvement in LV function which is sustained throughout the 1-year follow-up with 84% cardiac event free survival. If successful, MV repair may prevent LV redilation, while recurrent MR is associated with increased LV volumes.
Introduction of a Flexible Polymeric Heart Valve Prosthesis With Special Design for Mitral Position
Authors: Daebritz Sabine H. , Sachweh Jörg S. , Hermanns Benita , Fausten Bernd , Franke Andreas , Groetzner Jan , Klosterhalfen Bernd , Messmer Bruno J.
Published: September 2003

Background—

Current heart valve prostheses are constructed mimicking the native aortic valve. Special hemodynamic characteristics of the mitral valve such as a nonaxial central inflow with creation of a left ventricular vortex have so far not been taken into account. A new polycarbonaturethane (PCU) bileaflet heart valve prosthesis with special design for the mitral position is introduced, and results of animal testing are presented.

Methods and Results—

After in vitro testing, 7 PCU-prostheses and 7 commercial bioprostheses (Perimount, n=4; Mosaic, n=3) were implanted in mitral position into growing Jersey calves (age 3–5 months, weight 60–97 kg) for 20 weeks. 2-Dimensional echocardiography was performed after implantation and before sacrification. Autopsy included histologic, radiographic, and electron microscopic examination of the valves. In vitro durability was proven for >15 years. After implantation 2-dimensional-echocardiography showed no relevant gradient or regurgitation of any prosthesis. Clinical course of the animals with PCU valves was excellent. In contrast, 5 of 7 calves with bioprostheses were sacrificed after 1–9 weeks because of congestive heart failure. 2-Dimensional echocardiography of the PCU valves after 20 weeks showed mild leaflet thickening with trivial regurgitation; mean gradient was 8.1±5.0 mm Hg (weight: 160–170 kg). The explanted PCU prostheses revealed mild calcification and no structural degeneration. All of the Perimount bioprostheses were severely calcified and degenerated after 11±7 weeks. One Mosaic bioprosthesis was thrombosed after 1 week, and 2 showed severe and mild-to-moderate degeneration after 4 and 22 weeks, respectively.

Conclusions—

Polycarbonaturethane valve prostheses with special design for mitral position show excellent hemodynamic performance and durability in vivo. Calcification and structural changes are mild compared with bioprostheses. Controlled clinical studies are planned.
Emergence of cyclonic structures due to the interaction between near‐inertial oscillations and mesoscale eddies
Authors: Klein Patrice , Hua Bach Lien , Carton Xavier
Published: September 2003

We show that mesoscale eddies, through their effects on near‐inertial oscillations, can induce a spatially heterogeneous diffusion that depends on the vorticity sign. In turn, this heterogeneous diffusion breaks the cyclone–anticyclone symmetry on small time‐scales (compared to the diffusive time‐scale) and favours the emergence of cyclonic structures. Copyright © 2003 Royal Meteorological Society
AIRS channel selection for CO2 and other trace‐gas retrievals
Authors: Crevoisier Cyril , Chedin Alain , Scott Noelle A.
Published: September 2003

New high‐resolution infrared sounders, such as the National Aeronautics and Space Administration's Aqua satellite Atmospheric Infrared Sounder (AIRS) or the European Meteorological Satellite systems, MetOp Infrared Atmospheric Sounding Instrument (IASI), are expected to improve our capability to monitor atmospheric carbon dioxide (CO2) and other trace‐gas concentrations from space. As they present thousands of channels, the first problem arising is the selection of a set of channels presenting the best properties to retrieve these concentrations. A new method, the Optimal Sensitivity Profile (OSP) method, based on the study of the sensitivities of AIRS channels to variations in the vertical of the different atmospheric components, is proposed. It is then compared with two ‘classical’ methods based on the information content and the degrees of freedom for signal of the AIRS channels regarding CO2. Applying the OSP method to a set of 82 representative atmospheric situations obtained from the 2311 situations of the Thermodynamic Initial Guess Retrieval (TIGR) dataset, divided into three air masses (tropical, temperate and polar), and using simulated AIRS observations, a global set of 43 channels, well covering the whole atmospheric column, is selected for CO2 retrieval. The OSP method is finally used to select channels for retrieval of atmospheric nitrous oxide (N2O), carbon monoxide (CO) and methane (CH4) concentrations. Copyright © 2003 Royal Meteorological Society
Parallel decoding for burst error control codes
Authors: Fujiwara Eiji , Namba Kazuteru , Kitakami Masato
Published: September 2003

It is well known that sequential decoding methods for burst error control codes use Linear Feedback Shift Registers (LFSR). However, a parallel decoding method employing only combinational logic is preferable in certain applications, such as semiconductor memory systems and holographic memory systems, where a huge amount of data needs to be read or written at ultrahigh speed. This paper proposes a parallel decoding method for linear burst error control codes including the Fire code. In order to obtain the error pattern, this decoding method uses an inverse matrix of a nonsingular matrix which includes a sub‐matrix of the parity check matrix. Burst error correction is possible because correct burst error patterns are obtained only from frames that completely include the burst error pattern. Furthermore, this decoding method can also be applied to single byte error correcting codes with less hardware. The implementation of decoding circuits for burst and byte error control codes are illustrated in this paper. And their hardware complexity is also evaluated to show that the proposed method requires less hardware than the existing parallel decoding method. Finally, we will discuss about how the proposed decoding method can be extended to correct multiple burst or byte errors. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(1): 38–48, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10094
Design of IIR half‐band filters with arbitrary flatness and its application to filter banks
Authors: Yamashita Ryou , Zhang Xi , Yoshikawa Toshinori , Takei Yoshinori
Published: September 2003

Half‐band filters are important for applications to multirate signal processing and wavelets. Previously, FIR half‐band filters have mainly been treated. However, it should be recognized that the IIR filter can produce frequency characteristics similar to those of the FIR filter with a low order. Also, in the applications of filter banks and wavelets, design of a half‐band filter is needed in which the degree of flatness can be specified arbitrarily. In the present paper, a new design method is proposed for an IIR half‐band filter with an arbitrary degree of flatness. In the present design method, the analytical solution of the filter coefficients is given in the case of a maximally flat filter. Also, in the case of a specified degree of flatness, the amplitude error in the stopband can be specified in the design. Further, the stability of the filter is studied and then the minimum group delay for causal stability is clarified. Finally, the IIR half‐band filter is applied to the design of a two‐channel filter bank and the effectiveness of the present design method is proven. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(1): 10–18, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10114
Wavelet‐based perceptual watermarking with bit data embedded in still color images
Authors: Kino Masato , Wada Shigeo
Published: September 2003

As a way to protect copyright of digital content, researches into electronic watermarking have been carried out extensively. In this paper, an image watermarking method is proposed that can embed bit patterns with an arbitrary length by extending the wavelet‐based watermarking method based on the human visual system (HVS) proposed by Barni. For color images, weighting is provided by taking into account human visual characteristics in such a way that the visual effect on the brightness components is smaller. One of the characteristics of the present method is a significant improvement of convenience by using a long pseudorandom number sequence including bit data such as signatures, in contrast to the pseudorandom sequence without bit information used by Barni. Through simulations, it is verified that the proposed method has strong robustness to JPEG compression, cropping, color tone conversion, and mode deformation. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(1): 1–9, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10115
Induction of oxidative stress by L‐2‐hydroxyglutaric acid in rat brain
Authors: Latini Alexandra , Scussiato Karina , Borba Rosa Rafael , Leipnitz Guilhian , Llesuy Susana , Belló‐Klein Adriane , Dutra‐Filho Carlos Severo , Wajner Moacir
Published: September 2003

L‐2‐hydroxyglutaric acid (LGA) is the biochemical hallmark of L‐2‐hydroxyglutaric aciduria (L‐OHGA), an inherited neurometabolic disorder characterized by progressive neurodegeneration with cerebellar and pyramidal signs, mental deterioration, epilepsy, and subcortical leukoencephalopathy. Because the underlying mechanisms of the neuropathology of this disorder are virtually unknown, in this study we tested the in vitro effect of LGA on various parameters of oxidative stress, namely, chemiluminescence, thiobarbituric acid‐reactive substances (TBA‐RS), protein carbonyl formation (PCF), total radical‐trapping antioxidant potential (TRAP), total antioxidant reactivity (TAR), and the activities of the antioxidant enzymes catalase, glutathione peroxidase, and superoxide dismutase in cerebellum and cerebral cortex of 30‐day‐old rats. LGA significantly increased chemiluminescence, TBA‐RS, and PCF measurements and markedly decreased TAR values in cerebellum, in contrast to TRAP and the activity of the antioxidant enzymes, which were not altered by the acid. Similar but less pronounced effects were provoked by LGA in cerebral cortex. Moreover, the LGA‐induced increase of TBA‐RS was significantly attenuated by melatonin (N‐acetyl‐5‐methoxytryptamine) and by the combinations of ascorbic acid plus Trolox (soluble α‐tocopherol) and of superoxide dismutase plus catalase but not by the inhibitor of nitric oxide synthase Nω‐nitro‐L‐arginine methyl ester (L‐NAME), creatine, or superoxide dismutase or catalase alone in either cerebral structure. The data indicate that LGA provokes oxidation of lipids and proteins and reduces the brain capacity to modulate efficiently the damage associated with an enhanced production of free radicals, possibly by inducing generation of superoxide and hydroxyl radicals, which are trapped by the scavengers used. Thus, in case these findings can be extrapolated to human L‐OHGA, it may be presumed that oxidative stress is involved in the pathophysiology of the brain damage observed in this disorder. © 2003 Wiley‐Liss, Inc.
Calcium channel upregulation in response to activation of neurotrophin and surrogate neurotrophin receptor tyrosine kinases
Authors: Black Melony J. , Woo Yeunkyung , Rane Stanley G.
Published: September 2003

Modulation of calcium channel expression and function in the context of neurotrophin induced neuronal differentiation remains incompletely understood at a mechanistic level. We addressed this issue in the PC12 model neuronal system using patch clamp electrophysiology combined with ectopic expression of the human β platelet‐derived growth factor (βPDGF) receptor as a surrogate neurotrophin receptor system. PC12 cells ectopically expressing the human βPDGF receptor were treated with PDGF or nerve growth factor (NGF) for up to 7 days, and Ca2+ channel subtype expression was analyzed using selective pharmacological agents in both whole‐cell and cell‐attached single channel patch clamp configurations. PDGF‐induced upregulation of N‐ and P/Q‐type Ca2+ channel currents completely mimicked upregulation of these currents caused by NGF stimulation of the endogenous TrkA receptor tyrosine kinase (RTK). Neither PDGF nor NGF significantly altered L‐ or R‐type currents. Single channel recordings together with immunocytochemistry implied that growth factor‐induced increases in whole‐cell Ca2+ currents were a result of synthesis of new channels, and that whereas increased N channel density was apparent in the soma, additional P/Q channels distributed preferentially to extrasomal locations, most likely the proximal neurites. Finally, specific signaling‐deficient mutant forms of the βPDGF receptor were used to show that activation of Src, PI3‐kinase, RasGAP, PLCγ or SHP‐2 (some of which are implicated in certain other aspects of PC12 cell differentiation) by RTKs is not required for growth factor‐induced Ca2+ channel upregulation. In contrast, activation of the Ras‐related G‐protein Rap1 was found critical to this process. © 2003 Wiley‐Liss, Inc.
Market expansion strategy: development of a conceptual market expansion decision scorecard
Authors: Robinson Gary J. , Lundstrom William J.
Published: September 2003

Research related to market expansion strategy has primarily focused on assessing the ‘fit’ between the organization and external factors such as market attractiveness, competitive advantage and risk, with minimal attention to internal factors such as organizational structure, management systems and corporate culture.

The external factors are key ingredients in the formulation of a plan, however the internal factors are key drivers to the successful implementation of such a plan.

A review of the literature on market expansion strategy theory is examined to identify the most appropriate theoretical base for developing an integrated model for assessing various market expansion strategies based on external and internal factors.

The relationship among internal and external factors and the resources, risk and control inherent to each mode of market expansion are used to develop a model which provides direction as to the appropriate market expansion decision.

Copyright © 2003 John Wiley & Sons, Ltd.
Design issues and performance improvements in routing strategy on the Internet workflow
Authors: Yang Shin‐Jer
Published: September 2003

This paper addresses some performance issues for routing design, and influencing parameters for workflow routing. In particular, we propose an adaptive routing control algorithm of workflow systems. First, we finalize some main factors that affect the workflow's performance. Then, we design a new routing control algorithm, called ARC (Adaptive Routing Control), which is based on Dijkstra's algorithm to find the efficient and flexible path of workflow. Hence, we develop a simulation program to evaluate the performance of the ARC algorithm and other two routing methods. Consequently, our results indicate that the performance of ARC is much better than other two conventional routing approaches. Copyright © 2003 John Wiley & Sons, Ltd.
Solution strategies for the delamination analysis based on a combination of local‐control arc‐length and line searches
Authors: Alfano G. , Crisfield M. A.
Published: September 2003

The paper describes a local‐control arc‐length method which can be combined with various forms of line‐search procedure. In particular, a new ‘double‐line‐search’ method is developed, which significantly improves the solution procedure and turns out to be efficient and robust. Although the potential range of applications is wide, the method is here limited to the finite element analysis of delamination in a laminated composite using a cohesive‐zone model combined with interface elements. Three problems have been analysed and comparisons have been made with experimental results. Copyright © 2003 John Wiley & Sons, Ltd.
Combining variable latency pipeline with instruction reuse for execution latency reduction
Authors: Sato Toshinori , Arita Itsujiro
Published: September 2003

Operand bypass logic is likely to be one of the critical structures for future microprocessors to achieve high clock speed. The logic delay causes the execution time budget to be reduced significantly, so that the execution stage is divided into several stages. The variable latency pipeline (VLP) structure has the advantages of pipelining and pseudo‐asynchronous design. According to the source operands delivered to arithmetic units, VLP changes execution latency and thus achieves both high speed and low latency for most operands. In this paper we evaluate VLP with dynamically scheduled superscalar processors, using a cycle‐by‐cycle simulator. Our experimental results show that VLP successfully reduces the effective execution time, and thus relaxes the constraints on the operand bypass logic. We also evaluate the instruction reuse technique in order to support VLP. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(12): 11–21, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10498
IBCD: a fast collision detection algorithm based on image space using OBB
Authors: Fan Zhaowei , Wan Huagen , Gao Shuming
Published: September 2003

Image‐based collision detection algorithms make efficient use of the graphics rendering hardware and reduce the computational cost of CPU. In this article, a fast collision detection algorithm based on image space is presented, which combines graphics hardware capabilities with a simplified geometric representation (oriented bounding box) in order to rapidly detect collisions between complex objects. The method can deal with arbitrary polyhedra, while preserving the merits of image‐based collision detection algorithms. This is achieved by decomposing the surfaces of an object into a list of convex pieces. High efficiency of the algorithm is obtained by organizing the convex pieces into a binary tree with each node representing a convex piece, and by adopting triangle strip compression. The algorithm has been implemented and compared with related algorithms. Copyright © 2003 John Wiley & Sons, Ltd.
D‐Amino acids and D‐Tyr‐tRNATyr deacylase: stereospecificity of the translation machine revisited
Authors: Yang Hongbo , Zheng Gen , Peng Xiaozhong , Qiang Boqin , Yuan Jiangang
Published: September 2003

Until 30 years ago, it had been considered that D‐amino acids were excluded from living systems except for D‐amino acids in the cell wall of microorganisms. However, D‐amino acids, in the form of free amino acids, peptides and proteins, were recently detected in various living organisms from bacteria to mammals. The extensive distribution of bio‐functional D‐amino acids challenges the current concept of protein synthesis: more attention should be paid to the stereospecificity of the translation machine. Besides aminoacyl‐tRNA synthetases, elongation factor Tu and some other mechanisms, D‐Tyr‐tRNATyr deacylases provide a novel checkpoint since they specifically recycle misaminoacylated D‐Tyr‐tRNATyr and some other D‐aminoacyl‐tRNAs. Their unique structure represents a new class of tRNA‐dependent hydrolase. These unexpected findings have far‐reaching implications for our understanding of protein synthesis and its origin.