bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of an Icosahedral Quasicrystal in the Mg–Al–Pt System
Authors: Koshikawa Naokiyo , Yoda Shinichi , Edagawa Keiichi , Takeuchi Shin
Published: October 2002

A Frank-Kasper-type (FK-type) icosahedral phase (i-phase) has been found to form in the Mg–Al–Pt system of Mg45Al42Pt13 composition. The i-phase is formed by heating an amorphous phase produced by a melt-spinning technique up to 673 K. We have also investigated the formation of the FK-type i-phase in the ternary Mg–Al–X (X=Co, Ni, Rh and Au) systems and find no trace of the FK-type i-phase. The formation criteria for the FK-type i-phase have been discussed in terms of the electron number in the outer shell, the atomic size and the electronegativity of the third element in Mg–Al–X.
Improvements of ZnO Qualities Grown by Metal-Organic Vapor Phase Epitaxy Using a Molecular Beam Epitaxy Grown ZnO Layer as a Substrate
Authors: Ken-ichi Ogata Ken-ichi Ogata , Toru Kawanishi Toru Kawanishi , Keigou Maejima Keigou Maejima , Keiichiro Sakurai Keiichiro Sakurai , Shizuo Fujita Shizuo Fujita , Shigeo Fujita Shigeo Fujita
Published: October 2002

Zinc oxide (ZnO) of high quality was homoepitaxially grown by metal-organic vapor phase epitaxy (MOVPE) on molecular beam epitaxy (MBE)-grown ZnO layers after the pretreatment of the underlying MBE-ZnO at 1000°C in N2 which resulted in an atomically flat surface. In photoluminescence at 15 K, the 3 meV line width of the emission from donor-bound-excitons (D0X) and the observation of the fourth phonon replica of the emission from free-excitons (EX) have demonstrated the high potential of MOVPE growth of ZnO toward optical applications.
Effects of Ambient Gases on Current-Voltage Characteristics of Pt–GaN Schottky Diodes at High Temperatures
Authors: Kokubun Yoshihiro , Seto Taichiro , Nakagomi Shinji
Published: October 2002

The electrical characteristics of a Pt Schottky barrier to n-type GaN grown by metalorganic chemical vapor deposition and the effects of ambient gases on their properties have been investigated at elevated temperatures of up to 600°C. The current–voltage (I–V) characteristics of Schottky diodes remained steady at high temperatures of up to 600°C, although the rectifying ratio decreased with a rise in temperature. The I–V characteristics of Pt–GaN Schottky diodes depended on the ambient gases. Hydrogen decreases the barrier height of Pt–GaN Schottky diodes, whereas oxygen increases it. The barrier height changed significantly in the temperature range from 100 to 400°C due to the change of atmosphere from H2 to O2.
Laser-Diode-Tuned Sequential Laser Atom Cooling and Trapping for Nanofabrications
Authors: Sun Hong-Bo , Inouye Hironobu , Inouye Yasushi , Okamoto Kenji , Kawata Satoshi
Published: October 2002

We developed an atom-optical system that utilized a laser diode (LD) for both laser atom cooling and trapping. The LD is easy to maintain and operate, and is therefore suitable for engineering applications. The neutral atom beam of chromium was collimated by Doppler cooling and focused by a standing wave lens, and then directly deposited onto a silicon substrate. A nanograting structure with periodicity identical to the wavelength of the standing wave, 212.78 nm, was successfully achieved. The atom beam generation, collimating, focusing and deposition processes were experimentally and theoretically investigated.
A Lithium Liquid Metal Ion Source with a Sealed-Cone-Type Reservoir
Authors: Seki Setsuko , Tamura Hifumi , Akiba Tsuneo , Sumiya Hiroyuki
Published: October 2002

A sealed-cone-type liquid metal ion source (LMIS) suitable for lithium has been designed. It consists of a conical metal reservoir, a ceramic lid atop the reservoir covering the ion material, a tungsten filament, and a tungsten-needle emitter. The sealed-cone-type LMIS has good efficiency in heating and any contamination of the ion source due to the deposition of the source material is minimal. The chemical reaction of Li2CrO4 with Si was used to produce the Li liquid metal ion because it does so more easily than the heating of the Li metal does. The use of the Li primary ion in the secondary ion mass spectrometry (SIMS) analysis increased the yield of negative ions, which is similar to the case of the Cs primary ion. The use of light lithium ions improves beam focusing, which in turn increases the sensitivity of element analysis and ion imaging of a microarea.
Modeling of Thermal/Electric-Field Poling
Authors: Liu Xue-Ming , Zhang Han-Yi , Guo Yi-Li , Zheng Xiao-Ping , Li Yan-He
Published: October 2002

Employing three basic conclusions summarized from reported experimental results, we calculate the nonlinear coefficients in the bulk silica glass and silica fiber after thermal/electric-field poling and obtain relationships of their nonlinearities with the applied voltage V
0, the thickness of the depletion region L, and the poling time t. Theoretical results show that the second-order susceptibility χ(2) and the second-harmonic power P
2ω in the poled bulk glass are proportional to V
0 and V
0
2, respectively. There exists an optimal time t, and the effective nonlinear coefficient d
eff and P
2ω are approximately linear and square, respectively, with V
0 within the limit of V
0<3.5 kV and t>30 min in the normally poled fiber. Moreover, χ(2)∼0.2–1.8 pm/V for the bulk glass and d
eff∼0.01–0.14 pm/V for the silica fiber after typical poling. All of the results obtained are well consistent with the experimental reports.
A Frustrated Ferroelectric SmC* Phase Characterized by Peculiar Conoscopic Melatopes and Responsible for the V-Shaped Switching in Liquid Crystals
Authors: Takahiro Matsumoto Takahiro Matsumoto , Yasushi Suzuki Yasushi Suzuki , Masahiro Johno Masahiro Johno , Takuro Okugawa Takuro Okugawa , Masakazu Takeuchi Masakazu Takeuchi , Atsuo Fukuda Atsuo Fukuda
Published: October 2002

Many liquid crystal materials for the V-shaped switching were developed and identified to show an apparently single ferrielectric phase in the bulk. Questioning this identification, we have studied, at various temperatures, the Bragg reflected optical bands due to the helical structure, the dielectric responses, and the electric-field dependence of conoscopic figures. The results indicate that the “ferrielectric” phase is a frustrated ferroelectric SmC
* phase, where the characteristically biased direction of the most easily polarizable molecular short axis causes some difficulty in determining whether the melatopes emerge parallel or perpendicular to an applied electric field.
Wafer Fusion Condition for GaAs/AlGaAs System and Its Application to Laser Diode
Authors: Yokoyama Mitsuru , Akimoto Katsuya , Imada Masahiro , Noda Susumu
Published: October 2002

The wafer fusion technique is applied to a GaAs/GaAs system and the current–voltage (I–V) characteristics of the fused interface are investigated. A voltage barrier is observed at the n-GaAs/n-GaAs fused interface, but not at the p-GaAs/p-GaAs fused interface. The wafer fusion technique is also applied to laser fabrication, and a Fabry-Perot-type semiconductor laser using the GaAs/AlGaAs system is fabricated. The lasing oscillation at a wavelength of 785 nm is confirmed.
The threshold current density is estimated to be as low as 2.1 kA/cm2.
A Four-Junction Switch for Controlling the Opening and Closing of a Pickup Coil in High-Tc Superconducting Quantum Interference Device Magnetometer
Authors: Enpuku Keiji , Tokimizu Daishi , Kuroda Daisuke , Hijiya Shintaro
Published: October 2002

We study a method to prevent thermally activated flux entry through a flux dam in a high-T
c superconducting quantum interference device (SQUID) magnetometer. For this purpose, the circulating current flowing in a pickup loop of the magnetometer must be much below the critical current of the flux dam. In order to forcibly reduce the circulating current due to a residual magnetic field, we propose a switch consisting of four bicrystal junctions, instead of the conventional flux dam. Using the switch, we can electrically control the opening and closing of the pickup loop, and therefore, can reduce the circulating current to zero. The usefulness of the switch is demonstrated.
All-Optical Demultiplexing Using LiNbO3 Quasiphase-Matched Wavelength Converters
Authors: Xu Chang-Qing , Zhou Bing , Lam Yee Loy , Arahira Shin , Ogawa Yoh , Ito Hiromasa
Published: October 2002

All-optical demultiplexing based on the cascaded χ(2) process in a LiNbO3 quasiphase-matched wavelength converter is studied. Based on the obtained fundamental pulse width dependence of the normalized second harmonic generation (SHG) efficiency, it is predicted that efficiency of the cascaded χ(2) wavelength conversion can be enhanced greatly using a pump light with a short pulse. This prediction is verified by an experimental demonstration of demultiplexing from 40 GHz to 10 GHz. Despite the low average pump power (∼ 1 mW, 3.4 ps pulse width) used in this experiment, conversion efficiency as high as -17 dB was obtained. It is also found that the broadening of the converted pulse width is negligible in the present demultiplexing method.
Second Harmonic Generation and Photorefractive Effect in Dye-Doped Liquid Crystals
Authors: Kim Hyun-Wuk , Mun Jun-Ho , Yoon Choon-Sup , Kim Jong-Duk
Published: October 2002

Second harmonic generation (SHG) and photorefractive (PR) effects were observed in a PR cell of liquid crystals doped with nonlinear optical (NLO) chromophore. In general, photorefractive materials of liquid crystals have no second harmonic (SH) signals due to the absence of nonlinearity. However, we observed SHG using a Maker Fringes experimental setup and, simultaneously, the asymmetric energy exchange of high PR gain coefficient, 815 cm-1, using the PR cell.
Magnetic and Transport Properties of Mn-Based Fractional-Layer Oxide Superlattices
Authors: Nakagawa Naoyuki , Lippmaa Mikk , Shibuya Keisuke , Koinuma Hideomi , Kawasaki Masashi
Published: October 2002

We show that it is possible to grow fractional-layer oxide superlattices by embedding periodic layers of antiferromagnetic La0.6Sr0.4FeO3nanodots or nanowires in a ferromagnetic La0.6Sr0.4MnO3thin film. The fractional-layer superlattices were used to study spin canting effects at the nanostructure interfaces. The transport properties of the superlattices were shown to have a strong dependence on the nanodot size and density. A magnetic field-induced metal to insulator transition was observed when 25 nm nanodots were separated by three monolayers of La0.6Sr0.4MnO3. A very large magnetoresistance effect was observed below the ferromagnetic ordering temperature of the La0.6Sr0.4MnO3film.
Radio Emission from Supernovae and Gamma-Ray Bursters
Authors: Weiler Kurt W. , Panagia Nino , Montes Marcos J. , Sramek Richard A.
Published: October 2002

▪ Abstract  Study of radio supernovae over the past 20 years includes two dozen detected objects and more than 100 upper limits. From this work it is possible to identify classes of radio properties, demonstrate conformance to and deviations from existing models, estimate the density and structure of the circumstellar material and, by inference, the evolution of the presupernova stellar wind, and reveal the last stages of stellar evolution before explosion. It is also possible to detect ionized hydrogen along the line of sight, to demonstrate binary properties of the stellar system, and to show clumpiness of the circumstellar material. More speculatively, it may be possible to provide distance estimates to radio supernovae.

Over the past four years the afterglow of gamma-ray bursters has occasionally been detected in the radio, as well in other wavelengths bands. In particular, the interesting and unusual gamma-ray burst GRB980425, thought to be related to SN1998bw, is a possible link between supernovae and gamma-ray bursters. Analyzing the extensive radio emission data avaliable for SN1998bw, one can describe its time evolution within the well-established framework available for the analysis of radio emission from supernovae. This allows relatively detailed description of a number of physical properties of the object. The radio emission can best be explained as the interaction of a mildly relativistic (Γ ∼ 1.6) shock with a dense preexplosion stellar wind–established circumstellar medium that is highly structured both azimuthally, in clumps or filaments, and radially, with observed density enhancements. Because of its unusual characteristics for a Type Ib/c supernova, the relation of SN1998bw to GRB980425 is strengthened and suggests that at least some classes of GRBs originate in massive star explosions. Thus, employing the formalism for describing the radio emission from supernovae and following the link through SN1998bw/GRB980425, it is possible to model the gross properties of the radio and optical/infrared emission from the half-dozen GRBs with extensive radio observations. From this we conclude that at least some members of the “slow-soft” class of GRBs can be attributed to the explosion of a massive star in a dense, highly structured circumstellar medium that was presumably established by the preexplosion stellar system.
Kuiper Belt Objects: Relics from the Accretion Disk of the Sun
Authors: Luu Jane X. , Jewitt David C.
Published: October 2002

▪ Abstract  The Kuiper Belt consists of a large number of small, solid bodies in heliocentric orbit beyond Neptune. Discovered as recently as 1992, the Kuiper Belt objects (KBOs) are thought to hold the keys to understanding the early solar system, as well as the origin of outer solar system objects, such as the short-period comets and the Pluto-Charon binary. The KBOs are probably best viewed as aged relics of the Sun's accretion disk. Dynamical structures in the Kuiper Belt provide evidence for processes operative in the earliest days of the solar system, including a phase of planetary migration and a clearing phase, in which substantial mass was lost from the disk. Dust is produced to this day by collisions between KBOs. In its youth, the Kuiper Belt may have compared to the dust rings observed now around such stars as GG Tau and HR 4796A. This review presents the basic physical parameters of the KBOs and makes connections with the disks observed around nearby stars.
Shapes and Shaping of Planetary Nebulae
Authors: Balick Bruce , Frank Adam
Published: October 2002

▪ Abstract  We review the state of observational and theoretical studies of the shaping of planetary nebulae (PNe) and protoplanetary nebulae (pPNe). In the past decade, high-resolution studies of PNe have revealed a bewildering array of morphologies with elaborate symmetries. Recent imaging studies of pPNe exhibit an even richer array of shapes. The variety of shapes, sometimes multiaxial symmetries, carefully arranged systems of low-ionization knots and jets, and the often Hubble-flow kinematics of PNe and pPNe indicate that there remains much to understand about the last stages of stellar evolution. In many cases, the basic symmetries and shapes of these objects develop on extremely short timescales, seemingly at the end of AGB evolution when the mode of mass loss abruptly and radically changes. No single explanation fits all of the observations. The shaping process may be related to external torques of a close or merging binary companion or the emergence of magnetic fields embedded in dense outflowing stellar winds. We suspect that a number of shaping processes may operate with different strengths and at different stages of the evolution of any individual object.
A Generalist Looks Back
Authors: Salpeter Edwin E.
Published: October 2002

▪ Abstract  I fled with my parents from Hitler's Austria to Australia and studied physics at Sydney University. I obtained my Ph.D. in quantum electrodynamics with Rudolf Peierls at Birmingham University and came to Cornell to work with Hans Bethe. I have stayed at Cornell ever since, and I have essentially had only a single job in my whole life, but have switched fields quite often. I worked in nuclear astrophysics and in late-stellar evolution, estimated the Initial Mass Function for star formation and the metal enrichment of the interstellar medium. I suggested black hole accretion as the energy source for quasars, worked on molecule formation on dust grain surfaces, and was involved in 21-cm studies of gas clouds and disk galaxies. I collaborated with my wife on the neurobiology of the neuromuscular junction and with one of my daughters on the epidemiology of tuberculosis.
Modified Newtonian Dynamics as an Alternative to Dark Matter
Authors: Sanders Robert H. , McGaugh Stacy S.
Published: October 2002

▪ Abstract  Modified Newtonian dynamics (MOND) is an empirically motivated modification of Newtonian gravity or inertia suggested by Milgrom as an alternative to cosmic dark matter. The basic idea is that at accelerations below ao≈ 10−8cm/s2≈ cHo/6 the effective gravitational attraction approaches [Formula: see text], where gnis the usual Newtonian acceleration. This simple algorithm yields flat rotation curves for spiral galaxies and a mass-rotation velocity relation of the form M ∝ V4that forms the basis for the observed luminosity–rotation velocity relation—the Tully-Fisher law. We review the phenomenological success of MOND on scales ranging from dwarf spheroidal galaxies to superclusters and demonstrate that the evidence for dark matter can be equally well interpreted as evidence for MOND. We discuss the possible physical basis for an acceleration-based modification of Newtonian dynamics as well as the extention of MOND to cosmology and structure formation.
Cosmic Microwave Background Anisotropies
Authors: Hu Wayne , Dodelson Scott
Published: October 2002

▪ Abstract  Cosmic microwave background (CMB) temperature anisotropies have and will continue to revolutionize our understanding of cosmology. The recent discovery of the previously predicted acoustic peaks in the power spectrum has established a working cosmological model: a critical density universe consisting of mainly dark matter and dark energy, which formed its structure through gravitational instability from quantum fluctuations during an inflationary epoch. Future observations should test this model and measure its key cosmological parameters with unprecedented precision. The phenomenology and cosmological implications of the acoustic peaks are developed in detail. Beyond the peaks, the yet to be detected secondary anisotropies and polarization present opportunities to study the physics of inflation and the dark energy. The analysis techniques devised to extract cosmological information from voluminous CMB data sets are outlined, given their increasing importance in experimental cosmology as a whole.
Lyman-Break Galaxies
Authors: Giavalisco Mauro
Published: October 2002

▪ Abstract  In this paper we review the properties of Lyman-break galaxies, namely starburst galaxies at high redshifts, approximately in the range 2.5 < z < 5, identified by the colors of their far ultraviolet spectral energy distribution around the 912 Å Lyman continuum discontinuity. The properties of forming galaxies in the young universe are very important to constrain the history of galaxy evolution and the formation of the Hubble sequence, and until recently, they have remained largely unexplored. The Lyman-break technique has broken an impasse in the exploration of galaxies at high redshift that lasted for about two decades, and within a few years has yielded large and well-controlled samples of star-forming, but otherwise normal, galaxies at z > 2.5, including ∼1000 spectroscopic redshifts and another few thousands of robust candidates. This dataset has allowed us an unprecedented look at fundamental properties of galaxies at 20% of the Hubble time or less. In this paper, we discuss the nature of the Lyman-break galaxies and their properties, including star-formation rate, stellar and total mass, chemical abundance, morphology, and interstellar medium (ISM) kinematics, and outline their contribution to the stellar content of the universe and their connection to the galaxies observed in the present-day universe. We also discuss what the properties of these galaxies, in particular their spatial clustering, imply about the mechanisms of galaxy formation and about the relationship between the underlying distribution of dark matter and the activity of star formation.
MAKING ANALLY FROM ANENEMY: Plant Virology and the New Agriculture
Authors: Pogue Gregory P. , Lindbo John A. , Garger Stephen J. , Fitzmaurice Wayne P.
Published: October 2002

▪ Abstract  Historically, the study of plant viruses has contributed greatly to the elucidation of eukaryotic biology. Recently, concurrent with the development of viruses into expression vectors, the biotechnology industry has developed an increasing number of disease therapies utilizing recombinant proteins. Plant virus vectors are viewed as a viable option for recombinant protein production. Employing pathogens in the process of creating added value to agriculture is, in effect, making an ally from an enemy. This review discusses the development and use of viruses as expression vectors, with special emphasis on (+) strand RNA virus systems. Further, the use of virus expression vectors in large-scale agricultural settings to produce recombinant proteins is described, and the technical challenges that need to be addressed by agriculturists and molecular virologists to fully realize the potential of this latest evolution of plant science are outlined.
ANTIBIOTIC USE IN PLANT AGRICULTURE
Authors: McManus Patricia S. , Stockwell Virginia O. , Sundin George W. , Jones Alan L.
Published: October 2002

▪ Abstract  Antibiotics have been used since the 1950s to control certain bacterial diseases of high-value fruit, vegetable, and ornamental plants. Today, the antibiotics most commonly used on plants are oxytetracycline and streptomycin. In the USA, antibiotics applied to plants account for less than 0.5% of total antibiotic use. Resistance of plant pathogens to oxytetracycline is rare, but the emergence of streptomycin-resistant strains of Erwinia amylovora, Pseudomonas spp., and Xanthomonas campestris has impeded the control of several important diseases. A fraction of streptomycin-resistance genes in plant-associated bacteria are similar to those found in bacteria isolated from humans, animals, and soil, and are associated with transfer-proficient elements. However, the most common vehicles of streptomycin-resistance genes in human and plant pathogens are genetically distinct. Nonetheless, the role of antibiotic use on plants in the antibiotic-resistance crisis in human medicine is the subject of debate.
TOBACCOMOSAICVIRUSASSEMBLY ANDDISASSEMBLY: Determinants in Pathogenicity and Resistance
Authors: Culver James N.
Published: October 2002

▪ Abstract  The structural proteins of plant viruses have evolved to self-associate into complex macromolecules that are centrally involved in virus biology. In this review, the structural and biophysical properties of the Tobacco mosaic virus (TMV) coat protein (CP) are addressed in relation to its role in host resistance and disease development. TMV CP affects the display of several specific virus and host responses, including cross-protection, systemic virus movement, hypersensitive disease resistance, and symptom development. Studies indicate that the three-dimensional structure of CP is critical to the control of these responses, either directly through specific structural motifs or indirectly via alterations in CP assembly. Thus, both the structure and assembly of the TMV CP function as determinants in the induction of disease and resistance responses.
BIOLOGICALCONTROL OFPOSTHARVESTDISEASES OFFRUITS
Authors: Janisiewicz Wojciech J. , Korsten Lise
Published: October 2002

▪ Abstract  Losses from postharvest fruit diseases range from 1 to 20 percent in the United States, depending on the commodity. The application of fungicides to fruits after harvest to reduce decay has been increasingly curtailed by the development of pathogen resistance to many key fungicides, the lack of replacement fungicides, negative public perception regarding the safety of pesticides and consequent restrictions on fungicide use. Biological control of postharvest diseases (BCPD) has emerged as an effective alternative. Because wound-invading necrotrophic pathogens are vulnerable to biocontrol, antagonists can be applied directly to the targeted area (fruit wounds), and a single application using existing delivery systems (drenches, line sprayers, on-line dips) can significantly reduce fruit decays. The pioneering biocontrol products BioSave and Aspire were registered by EPA in 1995 for control of postharvest rots of pome and citrus fruit, respectively, and are commercially available. The limitations of these biocontrol products can be addressed by enhancing biocontrol through manipulation of the environment, using mixtures of beneficial organisms, physiological and genetic enhancement of the biocontrol mechanisms, manipulation of formulations, and integration of biocontrol with other alternative methods that alone do not provide adequate protection but in combination with biocontrol provide additive or synergistic effects.
Interleukin-1β Inhibits Expression of p21(WAF1/CIP1) and p27(KIP1) and Enhances Proliferation in Response to Platelet-Derived Growth Factor-BB in Smooth Muscle Cells
Authors: Nathe Tyler J. , Deou Jessie , Walsh Bethany , Bourns Brenda , Clowes Alexander W. , Daum Günter
Published: October 2002

Objective—

Intimal growth depends on smooth muscle cell (SMC) migration and proliferation and is regulated by thrombotic and inflammatory responses to vascular injury. Platelet-derived growth factor (PDGF)-BB and interleukin (IL)-1β have been shown to contribute to intimal hyperplasia and lesion progression in atherosclerosis. Mitogenic effects of IL-1 on SMCs have been reported and have been attributed to the expression of PDGF-A chain. In some, but not all, studies, IL-1β was found to cooperate with growth factors, including PDGF, in stimulating proliferation. The molecular basis for such cooperative effects is unknown and is the subject of the present study.

Methods and Results—

We demonstrate that in baboon aortic SMCs, IL-1β enhances the proliferation induced by PDGF-BB independently of PDGF-A signaling. IL-1β increases the phosphorylation of retinoblastoma protein, a pivotal step in the G
1
-to-S transition in the cell cycle. Analysis of expression levels of cyclins and cyclin-dependent kinase (CDK) inhibitors suggests that IL-1β stimulates CDKs by downregulating p21 and p27. Consistent with this hypothesis is the finding that CDK2 activity, induced by PDGF-BB, is enhanced 2.3±0.2-fold in the presence of IL-1β.

Conclusions—

Our data suggest that IL-1β may promote SMC proliferation after vascular injury and in atherogenesis by suppression of PDGF-BB–induced p21 and p27.
Thrombospondin-1 Mediates Smooth Muscle Cell Proliferation Induced by Interaction With Human Platelets
Authors: Ichii Takuya , Koyama Hidenori , Tanaka Shinji , Shioi Atsushi , Okuno Yasuhisa , Otani Shuzo , Nishizawa Yoshiki
Published: October 2002

Objectives—

Platelet adherence and activation are associated with smooth muscle cell (SMC) proliferation and arterial restenosis. This study examined platelet-SMC interaction on fibrillar type I collagen and analyzed the role of thrombospondin (TSP)-1 in platelet-induced SMC proliferation.

Methods and Results—

When SMCs cultured on fibrillar collagen were treated with human platelets (5 preparations), 7.45±2.94% of the cells passed through S phase within 24 hours, as determined by bromodeoxyuridine nuclear labeling. The addition of platelets markedly induced SMC TSP-1 mRNA expression and cell surface protein accumulation, which colocalized with adhered platelets, as determined by α
IIb
integrin immunostaining. Direct interaction of platelets with SMCs was necessary for its effect on proliferation and TSP-1 accumulation, as determined in the transwell culture system. The anti–TSP-1 blocking antibody strongly inhibited platelet-induced SMC proliferation by ≈60%. Analysis of the receptors for TSP-1 accumulation on the SMC surface revealed that β
1
integrins are mainly involved. The anti–β
1
integrin blocking antibody, which potently suppressed TSP-1 accumulation on SMCs, also markedly inhibited platelet-stimulated SMC proliferation.

Conclusions—

TSP-1 and β
1
integrin interaction is involved in platelet-stimulated SMC proliferation. This in vitro coculture system could prove useful for examining the molecular mechanism underlying platelet-induced vascular remodeling and for studying the mechanism of a tested drug for restenosis.
Prognostic Significance of Ultrasound Myocardial Tissue Characterization in Patients With Cardiac Amyloidosis
Authors: Koyama Jun , Ray-Sequin Patricia A. , Falk Rodney H.
Published: October 2002

Background

—

Cycle-dependent variation of myocardial integrated backscatter (CV-IB) is an objective measurement that may detect myocardial abnormalities. However, no data exist about the prognostic value of CV-IB in primary cardiac amyloidosis.

Methods and Results

—

We prospectively examined 208 consecutive biopsy-proven patients with primary amyloidosis. The magnitude of CV-IB was analyzed at the interventricular septum and left ventricular (LV) posterior wall and its prognostic value was compared with standard Doppler measurements with to the Tei index (isovolumic contraction time plus isovolumic relaxation time divided by ejection time). One hundred thirty-three patients had cardiac involvement (mean LV thickness > 12 mm). Forty-one patients (20%) (32 cardiac deaths) died during a mean follow-up of period of 307±156 days. Univariate analysis showed that the CV-IB at the LV posterior wall was the best predictor of cardiac death (
P
<0.0001) and all-cause death (
P
< 0.0001). The Tei index did not identify patients at risk of death. Multivariate analysis showed that CV-IB at the LV posterior wall was the only independent predictor of both cardiac and overall deaths.

Conclusions

—

Among patients with cardiac amyloidosis, CV-IB at the LV posterior wall is a powerful predictor of clinical outcome and is superior to standard echocardiographic/Doppler flow indexes.
Role of Angiotensin II–Regulated Apoptosis Through Distinct AT
1
and AT
2
Receptors in Neointimal Formation
Authors: Suzuki Jun , Iwai Masaru , Nakagami Hironori , Wu Lan , Chen Rui , Sugaya Takashi , Hamada Mareomi , Hiwada Kunio , Horiuchi Masatsugu
Published: October 2002

Background—

In vitro studies suggest that angiotensin II type 1 and type 2 (AT
1
and AT
2
) receptors exert opposite effects in terms of vasoconstriction, natriuresis, and cell growth, but the role of these receptors in cardiovascular remodeling in vivo is still an enigma. In this study, we tested the hypothesis that AT
2
exerts an antiproliferative effect by inducing apoptosis, thereby antagonizing AT
1a
in vascular remodeling.

Methods and Results—

Vascular injury was induced by polyethylene cuff placement around the left femoral artery of AT
1a
-null (AT
1a
KO), AT
2
-null (AT
2
KO), and wild-type mice. Neointimal formation as well as DNA synthesis in vascular smooth muscle cells (VSMC) after vascular injury was exaggerated in AT
2
KO mice, but they were both suppressed in AT
1a
KO mice compared with those in wild-type mice. In contrast, the number of apoptotic cells in the injured artery in VSMC was significantly increased in AT
1a
KO mice but decreased in AT
2
KO mice. Reverse transcriptase–polymerase chain reaction analysis revealed that the expression of
bax
mRNA was attenuated in AT
2
KO mice. On the other hand, the expression of
bcl-2
and
bcl-x
L
mRNA was enhanced in AT
2
KO mice but attenuated in AT
1a
KO mice. Immunohistochemical staining with antibody to the
bcl-2
protein family supported these results.

Conclusions—

Our results suggest that AT
2
exerts antiproliferative effects and proapoptotic changes in VSMC by counteracting AT
1a
in the process of neointimal formation after vascular injury.
Development of Heart Failure and Congenital Septal Defects in Mice Lacking Endothelial Nitric Oxide Synthase
Authors: Feng Qingping , Song Wei , Lu Xiangru , Hamilton Joel A. , Lei Ming , Peng Tianqing , Yee Siu-Pok
Published: October 2002

Background—

Nitric oxide (NO) produced by endothelial NO synthase (eNOS) plays an important role in the regulation of cell growth, apoptosis, and tissue perfusion. Recent studies showed that mice deficient in eNOS developed abnormal aortic bicuspid valves. The aim of the present study was to additionally investigate the role of eNOS in heart development.

Methods and Results—

We examined postnatal mortality, cardiac function, and septum defects in
eNOS
−/−
,
eNOS
+/−
, and wild-type mice. Postnatal mortality was significantly increased in
eNOS
−/−
(85.1%) and
eNOS
+/−
(38.3%) compared with wild-type mice (13.3%,
P
<0.001). Postmortem examination found severe pulmonary congestion with focal alveolar edema in mice deficient in eNOS. Heart shortening determined by ultrasound crystals was significantly decreased in
eNOS
−/−
compared with wild-type mice (
P
<0.05). Congenital atrial and ventricular septal defects were found in neonatal hearts. The incidence of atrial or ventricular septal defects was significantly increased in
eNOS
−/−
(75%) and
eNOS
+/−
(32.4%) neonates compared with those of the wild-type mice (4.9%). At embryonic days 12.5 and 15.5, cardiomyocyte apoptosis and myocardial caspase-3 activity were increased in the myocardium of
eNOS
−/−
compared with wild-type embryos (
P
<0.01), and increases in apoptosis persisted to neonatal stage in
eNOS
−/−
mice.

Conclusions—

Deficiency in eNOS results in heart failure and congenital septal defects during cardiac development, which is associated with increases in cardiomyocyte apoptosis. Our data demonstrate that eNOS plays an important role in normal heart development.
Aspirin Plus Coumarin Versus Aspirin Alone in the Prevention of Reocclusion After Fibrinolysis for Acute Myocardial Infarction
Authors: Brouwer Marc A. , van den Bergh Paul J.P.C. , Aengevaeren Wim R.M. , Veen Gerrit , Luijten Hans E. , Hertzberger Don P. , van Boven Ad J. , Vromans Ralf P.J.W. , Uijen Gérard J.H. , Verheugt Freek W.A.
Published: October 2002

Background

—

Despite the use of aspirin, reocclusion of the infarct-related artery occurs in ≈30% of patients within the first year after successful fibrinolysis, with impaired clinical outcome. This study sought to assess the impact of a prolonged anticoagulation regimen as adjunctive to aspirin in the prevention of reocclusion and recurrent ischemic events after fibrinolysis for ST-elevation myocardial infarction.

Methods and Results

—

At coronary angiography <48 hours after fibrinolytic therapy, 308 patients receiving aspirin and intravenous heparin had a patent infarct-related artery (Thrombolysis In Myocardial Infarction [TIMI] grade 3 flow). They were randomly assigned to standard heparinization and continuation of aspirin alone or to a 3-month combination of aspirin with moderate-intensity coumarin, including continued heparinization until a target international normalized ratio (INR) of 2.0 to 3.0. Angiographic and clinical follow-up were assessed at 3 months. Median INR was 2.6 (25 to 75th percentiles 2.1 to 3.1). Reocclusion (≤TIMI grade 2 flow) was observed in 15% of patients receiving aspirin and coumarin compared with 28% in those receiving aspirin alone (relative risk [RR], 0.55; 95% CI 0.33 to 0.90;
P
<0.02). TIMI grade 0 to 1 flow rates were 9% and 20%, respectively (RR, 0.46; 95% CI, 0.24 to 0.89;
P
<0.02). Survival rates free from reinfarction and revascularization were 86% and 66%, respectively (
P
<0.01). Bleeding (TIMI major and minor) was infrequent: 5% versus 3% (
P
=NS).

Conclusions

—

As adjunctive to aspirin, a 3-month-regimen of moderate-intensity coumarin, including heparinization until the target INR is reached, markedly reduces reocclusion and recurrent events after successful fibrinolysis. This conceptual study provides a mechanistic rationale to further investigate the role of prolonged anticoagulation after fibrinolytic therapy.
Positive Association of the Endothelial Nitric Oxide Synthase Gene Polymorphisms With High-Altitude Pulmonary Edema
Authors: Droma Yunden , Hanaoka Masayuki , Ota Masao , Katsuyama Yoshihiko , Koizumi Tomonobu , Fujimoto Keisaku , Kobayashi Toshio , Kubo Keishi
Published: October 2002

Background—

A defect of nitric oxide (NO) synthesis in the lung of high-altitude pulmonary edema (HAPE) has been suggested to contribute to its exaggerated pulmonary hypertension. Several polymorphisms have been identified in the gene encoding endothelial nitric oxide synthase (eNOS), which is a key enzyme responsible for NO synthesis, some of which were reported to be associated with vascular disorders.

Methods and Results—

We studied 41 HAPE-susceptible subjects (HAPE-s) and 51 healthy climbers (control group) in a Japanese population. We examined 2 polymorphisms of the eNOS gene, including the Glu298Asp variant and 27-base pair (bp) variable numbers of tandem repeats using polymerase chain reaction followed by restriction fragment length polymorphism. The Asp allelic frequency of the Glu298Asp variant was 25.6% in the HAPE-s and 9.8% in the controls, which was significantly different between the two groups (
P
=0.0044). The eNOS4a allelic frequency of 27-bp variable numbers of tandem repeats was 23.2% in the HAPE-s, significantly higher than that of 6.9% in the controls
(P
=0.0016). In HAPE-s group, 11 of 41 (26.8%) subjects possessed simultaneously both of the two significant alleles, but among the controls, none did, which showed a high statistical difference between the two groups (
P
=0.000059).

Conclusions—

Both polymorphisms of the eNOS gene were significantly associated with HAPE. A genetic background may underlie the impaired NO synthesis in the pulmonary circulation of HAPE-s. These polymorphisms could be genetic markers for predicting the susceptibility to HAPE.
Preservation of the Baroreceptor Heart Rate Reflex by Chemical Sympathectomy in Experimental Heart Failure
Authors: Mircoli Luca , Fedele Luigi , Benetti Marica , Bolla Giovanni Battista , Radaelli Alberto , Perlini Stefano , Ferrari Alberto U.
Published: October 2002

Background—

The mechanisms underlying impaired baroreflex sensitivity in congestive heart failure (CHF) are incompletely understood. The purpose of the present study was to test the hypothesis that this alteration depends on the marked degree of sympathetic overactivity known to characterize the CHF syndrome.

Methods and Results—

Eight-week-old rats were subjected to induction of postmyocardial infarction CHF obtained by coronary ligation (Lig), chronic chemical sympathectomy by 6-hydroxydopamine (Sx), both interventions (Sx-Lig), or neither intervention (Veh-Sham, sham surgery, and vehicle administration). Four weeks after infarction, in conscious state, baroreflex sensitivity was assessed from the bradycardic responses to graded phenylephrine-induced elevations in blood pressure (BP). Left ventricular (LV) diameter was assessed by echocardiography, and plasma catecholamines were assayed to estimate sympathetic activity. Lungs were eventually excised and weighed (LW). CHF was associated with the following: (1) no changes in BP and heart rate; (2) sympathetic overactivity (norepinephrine, 320.2±53.8 pg/mL for Veh-Lig versus 173.4±20.5 pg/mL for Veh-Sham,
P
<0.01), prevented by Sx (181.2±35.5 pg/mL for Sx-Lig versus 159.8±33.1 pg/mL for Sx-Sham,
P
=NS); (3) LV enlargement (10.3±0.7 mm for Veh-Lig versus 6.8±0.6 mm for Veh-Sham,
P
<0.01), irrespective of Sx (9.7±0.7 mm for Sx-Lig versus 6.6±0.5 mm for Sx-Sham,
P
<0.01); (4) pulmonary congestion (LW, 7.55±0.40 mg per gram of body weight for Veh-Lig versus 5.21±0.44 mg per gram of body weight for Veh-Sham,
P
<0.01), marginally attenuated by Sx (6.54±0.28 mg per gram of body weight for Sx-Lig versus 4.98±0.22 mg per gram of body weight for Sx-Sham,
P
<0.05); (5) reduction in baroreflex sensitivity (0.443±0.032 ms/mm Hg for Veh-Lig versus 0.860±0.420 ms/mm Hg for Veh-Sham,
P
<0.01), entirely prevented by Sx (1.217±0.058 ms/mm Hg for Sx-Lig versus 1.345±0.093 ms/mm Hg for Sx-Sham,
P
=NS).

Conclusions—

In early post-MI CHF, sympathectomy only partially attenuated LV dysfunction and entirely prevented baroreflex sensitivity impairment that arises from enhanced sympathetic activity.
Effect of Rosiglitazone Treatment on Nontraditional Markers of Cardiovascular Disease in Patients With Type 2 Diabetes Mellitus
Authors: Haffner Steven M. , Greenberg Andrew S. , Weston Wayde M. , Chen Hongzi , Williams Ken , Freed Martin I.
Published: October 2002

Background

—

Markers of systemic inflammation (eg, C-reactive protein [CRP] and interleukin-6 [IL-6]) have been proposed to be “nontraditional” risk factors for cardiovascular disease in patients with type 2 diabetes mellitus. Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of atherosclerotic plaque rupture, which raises the possibility of the use of MMP-9 levels as a marker for future myocardial infarction or unstable angina. In vitro and animal studies suggest that thiazolidinediones can reduce the expression of these markers. The purpose of this analysis was to determine whether rosiglitazone alters serum concentrations of CRP, IL-6, MMP-9, and white blood cell count (WBC) and to examine the relationship of these effects with demographic and disease variables.

Methods and Results

—

CRP, IL-6, MMP-9, and WBC were analyzed from stored frozen serum samples obtained from patients with type 2 diabetes who completed a 26-week randomized, double-blind, placebo-controlled study. After 26 weeks of rosiglitazone treatment, the percentage reductions in mean CRP, MMP-9, and WBC levels were statistically significant compared with baseline and placebo (
P
<0.01). The percentage reduction in mean IL-6 was small and similar in the rosiglitazone and placebo groups. The change in each inflammatory marker from baseline to week 26 was significantly correlated (
P
<0.05) with each of the other markers, as well as with the homeostasis model assessment estimate of insulin resistance.

Conclusions

—

Rosiglitazone reduces serum levels of MMP-9 and the proinflammatory marker CRP in patients with type 2 diabetes, which indicates potentially beneficial effects on overall cardiovascular risk.
Consensus Conference Report
Authors: Zaroff Jonathan G. , Rosengard Bruce R. , Armstrong William F. , Babcock Wayne D. , D’Alessandro Anthony , Dec G. William , Edwards Niloo M. , Higgins Robert S. , Jeevanandum Valluvan , Kauffman Myron , Kirklin James K. , Large Stephen R. , Marelli Daniel , Peterson Tammie S. , Ring W. Steves , Robbins Robert C. , Russell Stuart D. , Taylor David O. , Van Bakel Adrian , Wallwork John , Young James B.
Published: October 2002

The shortage of available donor hearts continues to limit cardiac transplantation. For this reason, strict criteria have limited the number of patients placed on the US waiting list to ≈6000 to 8000 per year. Because the number of available donor hearts has not increased beyond ≈2500 per year, the transplant waiting list mortality rate remains substantial. Suboptimal and variable utilization of donor hearts has compounded the problem in the United States. In 1999, the average donor yield from 55 US regions was 39%, ranging from 19% to 62%. This report provides the detailed cardiac recommendations from the conference on “Maximizing Use of Organs Recovered From the Cadaver Donor” held March 28 to 29, 2001, in Crystal City, Va. The specific objective of the report is to provide recommendations to improve the evaluation and successful utilization of potential cardiac donors. The report describes the accuracy of current techniques such as echocardiography in the assessment of donor heart function before recovery and the impact of these data on donor yield. The rationale for and specific details of a donor-management pathway that uses pulmonary artery catheterization and hormonal resuscitation are provided. Administrative recommendations such as enhanced communication strategies among transplant centers and organ-procurement organizations, financial incentives for organ recovery, and expansion of donor database fields for research are also described.
Electrophysiological Response of the Right Atrium to Ibutilide During Typical Atrial Flutter
Authors: Cheng Jie , Glatter Kathryn , Yang Yanfei , Zhang Shulong , Lee Randall , Scheinman Melvin M.
Published: October 2002

Background—

The efficacy of ibutilide in conversion of atrial fibrillation and flutter (AFL) has been demonstrated. However, its electrophysiological effects on human atria have not been fully studied.

Methods and Results—

Twelve patients with typical AFL were studied. Electrograms were recorded from the anterolateral right atrium, His bundle position, and coronary sinus. During AFL, we measured the conduction time, CTi, through the isthmus between the tricuspid annulus and eustachian ridge and the conduction time, CTni, through the remainder of the right atrium. Resetting response curves and atrial effective refractory periods were determined with single extrastimuli delivered in the tricuspid annulus–eustachian ridge isthmus. After infusion of ibutilide (2 mg over 15 minutes), AFL cycle length (CL) increased from 260±30 to 295±39 ms (
P
<0.0003) because of an increase in either CTi, CTni, or both. Effective refractory periods increased from 149±16 to 208±26 ms (
P
<0.001). AFL CL variability increased, with a rightward shift of the resetting response curves and loss of full excitability. In 8 patients, AFL was terminated by atrial overdrive pacing after ibutilide at CLs equal to or longer than those that were not effective at baseline, which was caused by orthodromic block in the tricuspid annulus–eustachian ridge isthmus or was associated with development of transient rapid rhythms around newly formed sites of intra-atrial conduction block.

Conclusions—

Ibutilide causes prolongation of AFL CL and increased CL variability by abolishment of a fully excitable gap. Ibutilide may facilitate pace termination of AFL by development of new short-lived reentry around functional blocks.
Soluble Intercellular Adhesion Molecule-1, Soluble Vascular Adhesion Molecule-1, and the Development of Symptomatic Peripheral Arterial Disease in Men
Authors: Pradhan Aruna D. , Rifai Nader , Ridker Paul M.
Published: October 2002

Background—

Elevated levels of soluble cellular adhesion molecules have been linked to the development of occlusive coronary events in otherwise healthy individuals. It is not certain, however, whether similar relationships exist for the development of early systemic atherosclerosis.

Methods and Results—

In a prospective, nested case-control study conducted among 14 916 middle-aged men, we evaluated the relationship between baseline levels of soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and the subsequent development of symptomatic peripheral arterial disease (PAD) during a 9-year follow-up period. Median levels of sICAM-1 but not sVCAM-1 were significantly higher at baseline among men who developed PAD than among those who did not (285.2 versus 267.8 ng/mL [
P
=0.005] for sICAM-1 and 701.0 versus 709.3 ng/mL [
P
=0.8] for sVCAM-1). In analyses adjusted for age and smoking, the odds ratio in the highest compared with the lowest quartile of sICAM-1 was 3.9 (95% CI 1.7 to 8.6;
P
trend
=0.001). After additional adjustment for lipid and nonlipid risk factors, including C-reactive protein, elevated sICAM-1 remained significantly associated with subsequent PAD (OR 3.5, 95% CI 1.4 to 8.5,
P
trend
=0.008). Whereas a monotonic dose-response relationship was evident over the full spectrum of ICAM-1 levels, elevated sVCAM-1 was not associated with future PAD in either age- and smoking-adjusted or fully adjusted models.

Conclusions—

Elevated levels of sICAM-1 are independently associated with the development of accelerated atherosclerosis among otherwise healthy men even in the absence of acute coronary occlusion.