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In this work, we investigated the film growth and planarization properties of sequential polymerization initiated chemical vapor deposition method (SP-iCVD). Supersaturated concentration of monomer and small amount of initiator were introduced sequentially into chamber. The obtained film properties such as uniformity, polymer molecular weight and thermal stability were same or better than iCVD processed film. Additionally, good planarization of high aspect ratio (7:1) patterned wafer was demonstrated in SP-iCVD. The overburden from top of feature was within 20 nm and film thickness between isolated and dense feature areas was very uniform in this single-step process.

Ion-induced damage on organic materials has been evaluated with secondary ion mass spectrometry. However, conventional sputtering beams such as SF5+ and C60+ cannot etch organic materials without inducing damage, and evaluating the damage depth distribution in these materials is difficult. Large gas cluster ions can etch organic materials without damage, and in this study, the damaged layer thickness was evaluated by molecular depth profiling with Ar cluster ion beam. The characteristic molecular ions were not detected in the spectra after etching with Ar monomer beam, indicating that the chemical structures of phenyl-C61-butyric acid methyl ester (PCBM) and polystyrene (PS) were seriously damaged. The intensity of the fullerene molecular ion reached a peak at the depth of about 35 nm. For PS, the peak intensity of m/z 91 increased with sputtering depth and saturated at about 45 nm. These values agreed with the projection range of Ar+ in PCBM and PS, respectively. These results indicate that the ion-induced damage depth was the same as the projection range of its ion. Copyright © 2012 John Wiley & Sons, Ltd.

The emission of positive secondary ions from four amino acids (arginine, glycine, phenylalanine, and tyrosine) and from NaCl under irradiation with large Arn+ cluster ions was investigated by time-of-flight secondary ion mass spectrometry. Size-selected 5.5-keV Arn+ cluster ions with 300 ≤ n ≤ 2000 were used, and the flux of sputtered positive ions was monitored as function of cluster size n. For all cluster sizes, the protonated or the cationized molecular ions are observed in the mass spectra. In addition, the results show that with increasing cluster size, the number of fragment molecules strongly decreases in relation to the intact molecules, to the extent that the ratio of fragment to intact ions is 10% or less for the largest cluster ions. Generally, the ion yields Y+ were found to decrease for decreasing impact energy per cluster atom, E/n, and this attenuation was recorded down to values as low as E/n ~ 3 eV/atom. The general trend of Y+ versus E/n is similar for all targets and appears to follow a power-law dependence, Y+ ∝ (E/n)x, with x ~ 4. This pronounced yield change could be ascribed to a reduction of the ionization probability which is envisaged to depend on the presence of free protons. Their number is expected to decrease concurrently with the decreasing amount of fragmentation for large cluster ions (i.e. for low energies/atom). Copyright © 2012 John Wiley & Sons, Ltd.

The analysis of organic and biological substances by secondary-ion mass spectrometry (SIMS) has greatly benefited from the use of cluster ions as primary bombarding species. Thereby, depth profiling and three-dimensional (3D) imaging of such systems became feasible. Large Arn + cluster ions may constitute a further improvement in this direction. To explore this option, size-selected Arn + cluster ions with 300 ≤ n ≤ 2200 (bombarding energies 5.5 and 11 keV) were used to investigate the emission of positive secondary ions from four amino acid specimens (arginine, glycine, phenylalanine, and tyrosine) by time-of-flight SIMS. For all cluster sizes, the protonated molecule of the respective amino acid is observed in the mass spectra. With increasing cluster size the number of fragment ions decreases strongly in relation to the intact molecules, to the extent that the fraction of fragment ions amounts to less than 10% in some cases. Such ‘soft’ emission processes also lead the ejection of dimers and even multimers of the amino acid molecules. In the case of the phenylalanine, secondary ion species composed of up to at least seven phenylalanine moieties were observed. Tentatively, the ionization probability of the emitted molecules is envisaged to depend on the presence of free protons in the emission zone. Their number can be expected to decrease concurrently with the decreasing amount of fragmentation for large Arn + cluster ions (i.e. for low energies per cluster atom). Copyright © 2011 John Wiley & Sons, Ltd.

X-ray reflective measurements (XRR), atomic force microscopy and single wavelength ellipsometry were used to investigate the optical properties of thin l -leucine films deposited onto silicon substrates. The ellipsometry data (Ψ,Δ) were fitted with a four-layer-model, and the optical refractive index of the l -leucine film measured with ellipsometry was determined to be 1.37. With the conventional effective medium approximation theory and the ellipsometry results, the density of the l -leucine nanofilm was determined to be 70% (0.81 g/cm 3 ) of crystalline l -leucine. This value was in good agreement with the density of 69% (0.80 g/cm 3 ) obtained with XRR measurement. The ellipsometry measurements also enabled us to estimate the surface roughness or absorption layer of the film. This procedure of combined XRR and ellipsometry measurements could be a powerful tool for the determination of the (otherwise hard-to-determine) refractive index in thin organic material films with a rough surface layer.

Recent developments in SIMS with both Ar cluster ions and swift heavy ions are presented. With these primary beams, the analysis of organic semiconductors and animal cells shows that one of the key factors to realizing the SIMS analysis of organic materials is high-energy deposition near the surface. Molecular depth profiling and images of organic materials were demonstrated by using SIMS.

In this study, we evaluated the damage caused by large Ar cluster ion irradiation on polymeric materials, and demonstrated a technique for molecular depth profiling of polymer films. The surface chemical states of the polymers were analyzed with XPS. The chemical states of the polymethyl methacrylate (PMMA) sample etched with Ar monomer ion beams differed significantly from those of the unirradiated sample, but were preserved for the sample etched with Ar cluster ion beams. SIMS depth profiling of the PMMA and polystyrene (PS) films were also carried out by using large Ar cluster ion beams at incident energies between 5.5 and 13 keV, and the effects of incident energy on damage accumulation and depth resolution were investigated. The ratios of the signal intensity at zero fluence to the signal intensity at steady state decreased with increasing incident energy, whereas the depth resolution was little affected by incident energy. Copyright © 2010 John Wiley & Sons, Ltd.

The demand for direct analytical techniques for characterization and damage evaluation of organic devices has increased dramatically in recent years, along with an increase in the importance of these devices. In this study, we demonstrate direct analysis of model structures for organic light emitting diode (OLED) devices by using SIMS with large Ar cluster ion beams. We prepared single and multilayer films of organic semiconductor materials by vacuum evaporation and analyzed their surfaces with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Under bombardment with large Ar cluster ions, the predominant species observed were molecular ions from the organic materials, while small fragment ions were strongly suppressed. Moreover, the multilayer films were depth profiled with Ar cluster ion beams, and the interfaces between the organic layers could be clearly distinguished. These results show the promising potential of large Ar cluster ion beams for direct analysis of real organic semiconductor devices.

Molecular imaging of animal cells was successfully obtained by using the technique of MeV-energy probe secondary ion mass spectrometry (MeV-SIMS) and sample etching with Ar cluster ion beam. In order to indicate benefits of using Ar cluster beam for etching biomaterials, cholesterol and phospholipids were etched with Ar cluster ions and SIMS measurements for the before and after etching samples were performed. Moreover, secondary ion images of the animal cells etched with Ar cluster ions were acquired by using MeV-energy ion beam as a probe.

Molecular dynamics (MD) simulations of large argon clusters impacting on silicon solid targets were performed in order to study the transient process of crater formation and sputtering. The MD simulations demonstrate that the initial momentum of incident cluster is transferred to target surface atoms through multiple collision mechanism, where the initial momentum, which is along to the surface normal before impact, is deflected to lateral direction. This momentum transfer process was analyzed by the calculation of the velocity at the crater edge (the interface between cluster and target). In the case of Ar1000 cluster impact on Si(1 0 0) target at low energy per atom less than 40 eV/atom, the maximum value of lateral velocity of the crater edge increases in proportional to the velocity of incident cluster atoms. On the other hand, the crater edge velocity saturates over 40 eV/atom of incident energy per atom. In this case, the whole of constituent cluster atoms are implanted into the target and expand in both lateral and reflective directions at the subsurface region of the target. These MD simulations demonstrated that this collisional process result in the high yield sputtering of the target atoms.

We demonstrate depth profiling of polymer materials by using large argon (Ar) cluster ion beams. In general, depth profiling with secondary ion mass spectrometry (SIMS) presents serious problems in organic materials, because the primary keV atomic ion beams often damage them and the molecular ion yields decrease with increasing incident ion fluence. Recently, we have found reduced damage of organic materials during sputtering with large gas cluster ions, and reported on the unique secondary ion emission of organic materials. Secondary ions from the polymer films were measured with a linear type time-of-flight (TOF) technique; the films were also etched with large Ar cluster ion beams. The mean cluster size of the primary ion beams was Ar 700 and incident energy was 5.5 keV. Although the primary ion fluence exceeded the static SIMS limit, the molecular ion intensities from the polymer films remained constant, indicating that irradiation with large Ar cluster ion beams rarely leads to damage accumulation on the surface of the films, and this characteristic is excellently suitable for SIMS depth profiling of organic materials.

We investigated the effects of size and energy of large incident Ar cluster ions on the secondary ion emission of Si. The secondary ions were measured using a double deflection method and a time-of-flight (TOF) technique. The size of the incident Ar cluster ions was between a few hundreds and several tens of thousands of atoms, and the energy up to 60 keV. Under the incidence of keV energy atomic Ar ions, mainly atomic Si ions were detected, whereas Si cluster ions were rarely observed. On the other hand, under the incidence of large Ar cluster ions, the dominant secondary ions were Si n + (2 ⩽ n ⩽ 11). It has become clear that the yield ratio of secondary Si cluster ions was determined by the velocity of the incident cluster ions, and this strong dependence of the yield ratio on incident velocity should be related to the mechanisms of secondary ion emission under large Ar cluster ion bombardment.

We developed a processing technique for biological samples, that is, animal cells, for imaging mass spectrometry using gas cluster ion beams. Secondary ion mass spectrometry has been investigated for cellular imaging with high spatial resolution. Nanoscale processing techniques are needed for cellular level imaging, for example, for removing contamination from cell surfaces and exposing the insides of cells. In this study, we compared the mass spectrum of the unetched cell sample to that of the cell irradiated with an Ar cluster ion beam. The contamination was removed from the sample surface and the signals of intracellular components were detected. The results indicate that the cells were etched with low damage using the gas cluster ion beam. Finally, we compared the ion image of an unetched cell to that of an etched cell and demonstrated that the technique of cluster ion irradiation could be applied to the processing of samples for cellular level imaging mass spectrometry.

Secondary ion emission with large gas cluster ion is reviewed from the point of view of secondary ion mass spectroscopy (SIMS). We have proposed to use large cluster ions to realize fragment-free ionization for SIMS analysis for various organic materials, such as amino acids and peptides. When large cluster ions with optimized size and energy were incident on biomolecular samples, the relative yields of the fragment ions decreased drastically with the velocity of incident cluster ions. Molecular depth profiling capability is also demonstrated by using large gas cluster ions as the primary ion for SIMS.

Secondary ions produced from a Si target bombarded with Ar cluster ions much larger than the molecular ions have been investigated. Secondary ions have been measured for a Si target bombarded with large Ar cluster ions at an incident energy between 7.5 and 27.5 keV using a time-of-flight technique. The mean size of the Ar cluster ion was about 1000 atoms/cluster, and then the collision energy per atom is between a few tens of eV and a few hundreds of eV. Secondary silicon cluster ions were detected under large Ar cluster ion bombardment. In this study, we succeeded to accurately measure the dependence of secondary ion spectra obtained by large Ar cluster ions on the incident cluster-ion size using a time-of-flight technique combined a primary-ion beam deflector and a secondary-ion deflector. The dependence of the secondary ion spectra under large Ar cluster ion bombardment on the incident cluster size is discussed.

We propose to use cluster ions that are much larger than the molecular ions as primary ions for organic secondary ion mass spectrometry. Incident Ar cluster ion beams with energies from 10 to 20 keV and a mean size of about 1000 atoms/cluster were used. Secondary ions were measured for a thin arginine film target (200 nm) bombarded with large Ar cluster ions using a time-of-flight technique. Molecular ions of arginine and characteristic fragment ions were detected with high sensitivity. When large Ar cluster ions such as Ar1500 were incident on the arginine target, molecular ions of arginine were detected with little fragment ions. This indicates that large cluster ions can ionize arginine molecules without damaging them.

New surface modification processes have been demonstrated using gas cluster ion irradiations. Multiple collision and high energy density collision of cluster ions are responsible for “non-linear phenomena”, which play an important role in the surface modification process. Because of the unique interaction between cluster ions and surface atoms, atomistic mechanisms of cluster ion bombardment must be understood for the further developments of this technology. Cluster size is a unique parameter for cluster ions. One of the fundamental questions in this surface modification technique is the cluster size effect. It is important to use appropriate cluster size in each process. Size dependence of sputtering yields and secondary ion yields with large Ar cluster (N > 300) have been measured.

Surface oxidation of Si assisted by Ar cluster impact with a current density of a few μA/cm 2 under O 2 atmosphere was investigated. Thin-film formation by cluster ion beam presents a number of advantages such as atomic-scale surface smoothing, high density and precise stoichiometry. We used an Ar cluster ion beam with 20 keV and a mean size of 1000 atoms per cluster and measured the emission yields of Si + and SiO + after Ar cluster ion irradiation in O 2 atmosphere using a quadrupole mass spectrometer to investigate the dependence of Si surface oxidation on oxygen partial pressure. It was found that the Si surface was oxidized by Ar cluster ion irradiation in O 2 atmosphere.

Surface damage induced on biomolecules with gas cluster ion beam (GCIB) irradiation is significantly lower than with atomic or small cluster ion beams, and for this reason, surface analysis techniques such as secondary ion mass spectrometry (SIMS) have become one of the most important applications of GCIB, particularly for microscale chemical imaging of biomolecular species. Because of the low duty-cycle in time-of-flight (TOF)-SIMS, only less than 0.1 % of the incident ion beam is used for analysis, meaning that analysis with high spatial resolution can practically be extremely lengthy. The duty cycle can be significantly improved with the orthogonal acceleration (oa) TOF method because with this method secondary ion mass spectra can be measured at high mass resolution without requiring a pulsed primary ion beam. In this study, we developed a gas cluster ion irradiation system mounted on an oa-TOF instrument and investigated the sputtering yield and secondary ion yield of arginine. Copyright © 2012 John Wiley & Sons, Ltd.

Ar cluster ion beams provide unique opportunities for organic material analysis. SIMS with Ar cluster ion beams have been utilized for thin films of biomaterials and organic semiconductor multilayers. No degradation in SIMS spectra was found after sputtering with Ar cluster ion beams. In addition, a damage layer formed with ion irradiation of monomer Ga at a dose of 1 × 1014 ions/cm2 was removed with an Ar cluster beam without additional damage being created. The structure and depth of damage induced with monomer ions can be evaluated with Ar cluster SIMS. The measured thickness of the damaged layer is very close to the value calculated with TRIM. These results indicate that damage in organic materials introduced with energetic ions can be evaluated with this technique. Copyright © 2012 John Wiley & Sons, Ltd.

The surface morphology and sputtering rate of polymethylmethacrylate (PMMA) samples bombarded with size-selected Ar cluster ion beam (1000-16000 atoms/cluster) was investigated. The incident cluster ion size was selected before irradiation by using the time-of-flight (TOF) method. The sputtering rates decreased with increasing incident cluster size at constant total energy. The average surface roughness values measured by AFM after 25 nm etching with 20 keV Ar 1000 + and Ar 16000 + were 4.0 ± 0.4 and 0.78 ± 0.09 nm, respectively. Thus, small clusters would be effective for high-speed etching, and large clusters would be suitable for low-damage etching.

Abstract —Platelet aggregation is inhibited through a negative feedback mechanism by the l -arginine/nitric oxide (NO) pathway found in platelets themselves. We have shown that long-term smoking impairs the bioactivity of platelet-derived NO (PDNO), resulting in an increased platelet aggregability. However, little is known about the relation between other coronary risk factors and PDNO release. Accordingly, this study was undertaken to examine whether other coronary risk factors are related to the impairment of PDNO bioactivity. We measured collagen-induced PDNO release with an NO-selective electrode in 61 subjects (mean age 47 years, range 24 to 74 years) who underwent complete physical and laboratory examinations. There was a significant inverse correlation between PDNO release and the number of coronary risk factors ( r =−0.61, P r =−0.33, P r =−0.40, P r =−0.31, P r =−0.33, P P r 2 =0.51), with smoking ( F =37.8), age ( F =7.1), and mean arterial pressure ( F =5.1). Thus, we demonstrated that coronary risk factors are associated with an impairment of PDNO release by human platelets. Our findings may contribute to the understanding of the pathophysiological link between coronary risk factors and atherothrombotic disease.

Si was bombarded with size-selected 40 keV Ar cluster ions and positive secondary ions were measured using the time-of-flight technique under high and ultra-high vacuum (HV and UHV respectively) conditions. Si+ ions were main species detected under the incidence of 40 keV Ar cluster ions, and the yields of Si cluster ions such as Si4+ were also extremely high under both conditions. On the other hand, oxidized secondary ions such as SiO+ were detected with high intensity only under the HV condition. The yield ratios of oxidized ions decreased in UHV to less than 1% of their values in HV. The effect of residual gas pressure on Si cluster ion yields is relatively low compared to oxidized ions, and the UHV condition is required to obtain accurate secondary ion yields.

We measured the sputtering yield, surface roughness and surface damage of thin leucine films bombarded with Ar cluster ions and examined the usefulness of large gas cluster ions for the depth profiling of organic compounds. Ar cluster ion beams with a mean size of 2000 atoms/cluster and energies from 5 to 30 keV were used. Sputtering yields increased linearly with incident ion energy and were extremely high compared to inorganic materials. Surface damage was investigated by measuring positive secondary ions emitted from the leucine film before and after cluster ion irradiation. After irradiation the leucine surface became smoother. The yield ratio of protonated leucine ions to other fragment ions kept constant before and after Ar cluster ion irradiation. These results indicate that large gas cluster ions are useful for depth profiling of organic compounds.

In this report, we propose to use the incidence of cluster ions that are much larger than molecular ions as a fragment-free ionization technique for organic secondary ion mass spectrometry. Secondary ions were measured for amino acid and peptide targets bombarded with 3, 8 and 13 keV large Ar cluster ions. The relative yields of the fragment ions decreased drastically with increasing incident cluster size. Fragment-free ionization of the molecule was accomplished when large cluster ions with optimized size and energy were incident on a biomolecular sample.

The analysis of organic and biological substances by secondary-ion mass spectrometry (SIMS) has greatly benefited from the use of cluster ions as primary bombarding species. Thereby, depth profiling and three-dimensional (3D) imaging of such systems became feasible. Large Ar(n)(+) cluster ions may constitute a further improvement in this direction. To explore this option, size-selected Ar(n)(+) cluster ions with 300 ≤ n ≤ 2200 (bombarding energies 5.5 and 11 keV) were used to investigate the emission of positive secondary ions from four amino acid specimens (arginine, glycine, phenylalanine, and tyrosine) by time-of-flight SIMS. For all cluster sizes, the protonated molecule of the respective amino acid is observed in the mass spectra. With increasing cluster size the number of fragment ions decreases strongly in relation to the intact molecules, to the extent that the fraction of fragment ions amounts to less than 10% in some cases. Such 'soft' emission processes also lead the ejection of dimers and even multimers of the amino acid molecules. In the case of the phenylalanine, secondary ion species composed of up to at least seven phenylalanine moieties were observed. Tentatively, the ionization probability of the emitted molecules is envisaged to depend on the presence of free protons in the emission zone. Their number can be expected to decrease concurrently with the decreasing amount of fragmentation for large Ar(n)(+) cluster ions (i.e. for low energies per cluster atom).

In this work, we characterized the surface damage layer and sputtering yield of polycrystalline L-leucine films before and after irradiation with Ar cluster or monomer ion beams with x ray photoelectron spectroscopy and ellipsometry. Irradiation with Ar monomer ion beams induced heavy damage on the surface of L-leucine films, such as bond breaking and carbonization. In contrast, no significant surface damage was observed in the films irradiated with Ar cluster ion beams. The sputtering yield of L-leucine decreased dramatically with increasing fluence of monomer Ar ions and approached the value of the sputtering yield of graphite; but under irradiation with Ar cluster ion beams, the sputtering yield remained constant with fluence. The differences in sputtering yield behavior were explained in relation with the surface damage layer on organic materials. Thus, cluster ion beams could potentially be used to mill down biological materials without significant damage on the surface and could contribute to various applications in the analysis and processing of life matter.

The surface of L‐leucine films irradiated with an Ar5000 cluster ion beam (5 keV) was characterized by using the X‐ray reflective (XRR) measurement method, atomic force microscopy (AFM) and ellipsometry. No significant damage was detected on the surface of the L‐leucine films irradiated with the Ar cluster ion beam. Therefore, the large cluster‐low‐energy (about 1 eV/atom) beam would be suitable for low‐damage etching of organic materials.

In this study, we present molecular depth profiling of multilayer structures composed of organic semiconductor materials such as tris(8-hydroxyquinoline)aluminum (Alq3) and 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD). Molecular ions produced from Alq3 and NPD were measured by linear-type time-of-flight (TOF) mass spectrometry under 5.5 keV Ar700 ion bombardment. The organic multilayer films were analyzed and etched with large Ar cluster ion beams, and the interfaces between the organic layers were clearly distinguished. The effect of temperature on the diffusion of these materials was also investigated by the depth profiling analysis with Ar cluster ion beams. The thermal diffusion behavior was found to depend on the specific materials, and the diffusion of Alq3 molecules was observed to start at a lower temperature than that of NPD molecules. These results prove the great potential of large gas cluster ion beams for molecular depth profiling of organic multilayer samples. Copyright © 2009 John Wiley & Sons, Ltd.

Cluster ion implantation has a great potential for semiconductor manufacturing, such as ultra shallow junction formation and strain engineering of channel. Stress in Si implanted with carbon cluster ions (C 7 H 7 ) was much higher than that in Si implanted with carbon monomer ions. Multiple collisions of atoms occurred during cluster ion implantation, and a fully amorphized Si layer can be formed. The stress in the implanted layer strongly depends on the annealing condition. There are two different directions for the stress. One is parallel to the surface, which is usually measured with conventional X-ray diffraction. The other is perpendicular to the surface, which can be measured with in-plane X-ray diffraction technique. The stress perpendicular to the surface was about 50% of the stress parallel to the surface even after flash lamp annealing.

We demonstrate depth profiling of polymer materials by using large argon (Ar) cluster ion beams. In general, depth profiling with secondary ion mass spectrometry (SIMS) presents serious problems in organic materials, because the primary keV atomic ion beams often damage them and the molecular ion yields decrease with increasing incident ion fluence. Recently, we have found reduced damage of organic materials during sputtering with large gas cluster ions, and reported on the unique secondary ion emission of organic materials. Secondary ions from the polymer films were measured with a linear type time-of-flight (TOF) technique; the films were also etched with large Ar cluster ion beams. The mean cluster size of the primary ion beams was Ar(700) and incident energy was 5.5 keV. Although the primary ion fluence exceeded the static SIMS limit, the molecular ion intensities from the polymer films remained constant, indicating that irradiation with large Ar cluster ion beams rarely leads to damage accumulation on the surface of the films, and this characteristic is excellently suitable for SIMS depth profiling of organic materials.

We report two cases of vasospastic angina associated with anaphylactic reaction caused by nonsteroidal anti-inflammatory drugs (NSAIDs). Both patients exhibited anaphylactic manifestations, such as general rash and urticaria, along with angina pectoris with electrocardiographic ST-segment elevations after suppository administration of diclofenac sodium or indomethacin, the most commonly used NSAIDs. Although these patients had normal coronary arteriograms, intracoronary administration of ergonovine or acetylcholine provoked diffuse coronary artery spasms accompanied by chest pain and ischemic ST-segment changes. It is therefore suggested that an allergic mechanism may be involved as a causative factor of the coronary artery spasm induced by NSAIDs.

A 19-year-old man developed a huge coronary aneurysm and stenosis in the right coronary artery as a sequela of Kawasaki disease (KD) that resulted in recurrent episodes of myocardial infarction. Coronary ischemic events were successfully prevented after balloon angioplasty followed by coronary stent implantation into the stenotic lesion. The stent deployment may have an advantage compared with balloon angioplasty and other new devices for the treatment for patients with KD showing stenotic lesions without dense calcification.

Background Long-term smoking impairs endothelium-dependent vasodilation, which is mediated by nitric oxide (NO). However, it is unknown whether long-term smoking impairs the platelet-derived NO release, which regulates platelet aggregation. Methods and Results Platelet-derived electrical current induced by collagen was measured with an NO-selective electrode in 12 smokers and 11 nonsmokers. Collagen-induced intraplatelet cGMP and platelet aggregation was measured in smokers and nonsmokers. S -nitroso- N -acetyl- dl -penicillamine, a direct NO donor, dose dependently increased in electrical current ( r =.99). Collagen induced platelet aggregation and dose dependently increased electrical current ( r =.94). Collagen-induced electrical current and cGMP were significantly augmented by l -arginine, a precursor of NO, and attenuated by N G -monomethyl- l -arginine, an inhibitor of NO synthesis. Significant correlation was found between collagen-induced electrical current and cGMP ( r =.73). These findings indicate that the change in electrical current reflects the NO release through the l -arginine–NO pathway in platelets. Collagen-induced electrical current (6.7 versus 13.8 pA; P 9 platelets; P l -arginine increased cGMP levels in both smokers and nonsmokers, the level was still lower in smokers than in nonsmokers. The inhibitory effect of l -arginine on collagen-induced platelet aggregation was significantly lower in smokers than in nonsmokers ( P Conclusions These findings provide evidence that platelet-derived NO release is significantly impaired in long-term smokers, resulting in the augmentation of platelet aggregability.

Background P-selectin in platelets and endothelial cells mediates adhesive interaction with leukocytes to form thrombi. The purpose of the present study was to investigate the plasma levels of P-selectin in patients with unstable angina and in those with stable effort angina of different pathophysiologies. Methods and Results Plasma P-selectin levels were determined by a monoclonal antibody–based enzyme immunoassay on plasma samples taken from 12 patients with unstable angina, 11 patients with stable effort angina, and 15 healthy volunteers. Patients with unstable angina had angina at rest associated with ECG changes. In patients with unstable angina, plasma P-selectin levels within 1 hour (361±90 ng/mL) and at 3 hours (282±56 ng/mL) after angina were significantly ( P Conclusions Plasma P-selectin levels after angina increased significantly in patients with unstable angina but did not in patients with stable effort angina. These findings may contribute to understanding of the pathophysiology of the acute coronary syndrome of unstable angina.

Ar cluster ions in the size range 1000�16000 atoms/cluster were irradiated onto Si substrates at incident energies of 10 and 20 keV and the sputtering yields were measured. Incident cluster ions were size-selected by using the time-of-flight (TOF) method. The sputtering yield was calculated from the sputtered Si volume and irradiation dose. It was found that the sputtering yields decreased with increasing incident cluster size under the same incident energy conditions. The integrated sputtering yields calculated from the sputtering yields measured for each size of Ar cluster ions, as well as the cluster size distributions, were in good agreement with experimental results obtained with nonselected Ar cluster ion beams.