Laser Light-scattering Method Research Articles

Non-Destructive Quantification of In-Plane Depth Distribution of Sub-Surface Damage on 4H-SiC Wafers Using Laser Light Scattering

The development of non-destructive quantitative evaluation techniques for the in-plane depth distribution of sub-surface damage (SSD) layer induced by mechanical processing of chemical mechanical polishing (CMP) finished SiC wafers is essential to reduce the occurrence of crystal defects during epitaxial growth. Until now, no wafer inspection method has been able to nondestructively and quantitatively assess the in-plane depth distribution of the SSD. This study investigates the correlation between the scattered light intensity measured nondestructively by the Laser light scattering (LLS) method and the SSD depth estimated by destructive inspection using the Dynamic AGE-ing® method, a sublimation-controlled etching and growth process, to develop a novel non-destructive SSD inspection method. As a result, it was found that there is an exponential relationship between the scattered light intensity by the LLS method on the bare wafer surface and the depth of the SSD layer that contributes to the formation of in-grown stacking faults (IGSF) during subsequent epitaxial growth. The results show that SiC wafer inspection using the novel LLS method, which introduces this relational equation, enables non-destructive and quantitative evaluation of SSD depth and in-plane distribution.

Study of Laser Light Scattering Methods in Rapid Viability Assessment of Microorganisms under Antibiotics Exposure for Adaptation in Lab-on-A-Chip Format.

The antibiotic resistance (ABR) problem is becoming increasingly disturbing and it is important to implement express methods of ABR testing to allow operative antibiotic therapy decisions. The application of laser light scattering (LLS) in microbiological analysis for express ABR testing of microorganisms has been considered. The ways of miniaturization of laser light scattering for creating the bases of their integration into microbiological laboratory-on-a-chip (MLOC) for clinical express diagnostics have been analysed. The advantage of miniaturization in the context of clinical express analysis realization problems are investigated. A system of parallel measuring cells and illumination, enabling simultaneous testing of a group of antibiotics, was tested by splitting a laser beam with a two-dimensional collimator prepared of nanoporous anodic aluminum oxide. It has been demonstrated that the application of LLS methods, providing high concentration and mass sensitivity as well as a miniaturization potential, is an effective approach in the development of new generation diagnostic instruments. The studies have demonstrated the ability of methods to register effects of antibiotics on microbiological samples within 10 min. The following microorganisms were used in the study: Escherichia coli M-17, Lactobacillus plantarum, Bifidobacterium bifidum, Stenotrophomonas maltophilia.

Обнаружение частиц микропластика в растительных маслах

Наличие микро и нано частиц пластика в пищевых продуктах в настоящее время является актуальнейшей проблемой пищевой промышленности и одним из главных вопросов пищевой безопасности. При этом не существует ни чётких методик по определению таких частиц, ни способов очистки от них пищевых продуктов. В связи с тем, что вопрос о переработке пластика до сих пор не решён, а разлагающиеся пластиковые объекты находятся повсюду вокруг, крайне актуальным является изучение вопроса о наличии микроскопических частиц пластмасс (микропластика) в пищевых продуктах, об их размерах и количестве. В представленной работе впервые методом Динамического Лазерного Светорассеивания с помощью анализатора наночастиц «Zetatrac» было определено присутствие в некоторых растительных маслах микро и нано объектов, по своим характеристикам похожих на пластик. Определено распределение этих частиц по фракциям, их удельная поверхность и дзета потенциал. Было подсчитано содержание микро и нано частиц, идентифицированных, как пластик, в растительном масле. Оно колеблется от 2,5 до 9 миллиардов на один литр пищевого продукта. Высказано предположение, что возможной причиной наличия таких частиц в этом виде пищевых продуктов является то, что может происходить их экстракция из медленно разрушающейся пластиковой тары.Величина дзета потенциала, подсчитанная прибором на основании данных о движении частиц, находится в области от 20 до 30 мВ. Это значит, что микрочастицы в суспензии устойчивы и не склонны к коагуляции. Таким образом, самоочищение от них невозможно.

Early determination of bacteriological status of biological fluid samples as effective method of diagnosing infectious complications in patients of transplant clinic

The concept of quality assurance in the health care system is popular for medical institutions all over the world. The problem of global multidrug resistance of pathogenic and opportunistic flora causes an urgent need for new approaches and methods of renal failure (particularly bacteriuria) rapid diagnosis.Objectives. Evaluate the benefits of laser light-scattering method in early diagnosis of renal failure and infectious complications after kidney transplantation.Methods. 220 urine samples from 129 patients were examined. Each sample was evaluated by traditional method and an automated laser light-scattering system simultaneously.Results. The automated method allowed to get the result in an average of 2 hours and give a result of bacteriuria availability with indicating the class of the pathogen by Gram. Discrepancy between the results of classical and automated methods was observed in 6.8 % of all samples, which is the standard for similar clinical trials.Conclusions. Laser light-scattering method has clear advantages over traditional methods. Diagnosis of urinary tract infections in kidney recipients in a shorter time (3.5 hours) is especially important. The economic benefit of automated process allows to reduce the costs of the hospital for bacteriological studies by 1.5 times.

Aggregate formation in tauroursodeoxycholate solutions

The hydrodynamic radius (rH) values of simple tauroursodeoxycholate (TUDC) micelles formed between 12mM and 60mM TUDC solutions were measured using a laser light-scattering method to be nearly constant (∼15.4Å). Additionally, a kinetic dialysis technique was employed to determine the TUDC monomer concentrations with respect to the total TUDC concentrations. According to the chemical equilibrium treatment, a relationship between the TUDC monomer concentrations and the total TUDC concentrations was derived. By using a least-squares technique, the best curve-fitting to the kinetic dialysis data of the relationship predicted by the mass-action model was obtained. The equilibrium constants were also quantified. Their values together with the light-scattering results indicate that both TUDC dimers and simple TUDC micelles are formed from TUDC monomers by hydrophobic interaction. Moreover, the concentration of TUDC dimers is much higher than the concentration of simple TUDC micelles in TUDC solutions.

Diagnostic Potential of Endotoxin Scattering Photometry for Sepsis and Septic Shock

Endotoxin scattering photometry (ESP) is a novel Limulus amebocyte lysate (LAL) assay that uses a laser light-scattering particle-counting method. In the present study, we compared ESP, standard turbidimetric LAL assay, and procalcitonin assay for the evaluation of sepsis after emergency gastrointestinal surgery. A total of 174 samples were collected from 40 adult patients undergoing emergency gastrointestinal surgery and 10 patients with colorectal cancer undergoing elective surgery as nonseptic controls. Plasma endotoxin levels were measured with ESP and turbidimetric LAL assay, and plasma procalcitonin levels were assessed with a standard procalcitonin assay. Plasma endotoxin and procalcitonin levels increased corresponding to the degree of sepsis. Endotoxin scattering photometry significantly discriminated between patients with or without septic shock: sensitivity, 81.1%; specificity, 76.6%; positive predictive value, 48.4%; negative predictive value, 93.8%; and accuracy, 77.6%. The area under the receiver operating characteristic curve for septic shock with the ESP assay (endotoxin cutoff value, 23.8 pg/mL) was 0.8532 ± 0.0301 (95% confidence interval, 0.7841-0.9030; P < 0.0001). The predictive power of ESP was superior to that of turbidimetric assay (difference, 0.1965 ± 0.0588; 95% confidence interval, 0.0812-0.3117; P = 0.0008). There was no significant difference in predictive power between ESP and procalcitonin assay. Endotoxin scattering photometry also discriminated between patients with and without sepsis. Area under the receiver operating characteristic curve analysis showed that ESP had the best predictive power for diagnosing sepsis. In conclusion, compared with turbidimetric LAL assay, ESP more sensitively detected plasma endotoxin and significantly discriminated between sepsis and septic shock in patients undergoing gastrointestinal emergency surgery.

Novel endotoxin assay by laser light-scattering particle-counting method.

Exposure of Limulus amoebocyte lysate to endotoxin under stirring produced light-reflective particles that appeared to be coagulin polymers. A laser light-scattering particle counter, the PA-200, detected these particles sensitively. The PA-200 detected endotoxin at a concentration as low as 0.00015 EU/ml in 71 min, whereas the minimum endotoxin concentration measured by a turbidimeter, ET-2000, was 0.0005 EU/ml in 138 min. Moreover, PA-200 was much less affected by the presence of colored substances and refractive materials than was ET-2000. We propose that the high sensitivity, speed, and high interference tolerance of the laser light-scattering particle-counting method make it more useful than the widely used turbidimetric method for quantitative endotoxin assay.

Soluble aramid containing ether linkages: Synthesis, static and dynamic light scattering studies

Aromatic polyamide was synthesized via condensation polymerization of 4,4′-oxydianiline and isophthaloyl chloride using N, N′-dimethyl acetamide as solvent under anhydrous conditions. Aramid has been studied by laser light scattering (LLS) in dimethyl sulfoxide, a thermodynamically good solvent at 20 °C. Static and dynamic light scattering studies permitted to determine the weight average molecular weight 〈 M w〉, radius of gyration 〈 R g〉, second virial coefficient A 2, the hydrodynamic radius R H and the diffusion coefficient D. Light scattering experiments were conducted at five concentrations ranging from 0.2 to 2 g/L. This LLS method should also be very useful in the study of aggregation or association in a polymer system as long as the large “clusters” are reasonably stable in time. The intensity autocorrelation function obtained on the quasi-elastically scattered light showed a simple diffusive relaxation mode. The ratio of radius of gyration to the hydrodynamic radius, i.e., 〈 R g〉/〈 R H〉 ∼ 1.5, indicates that the polyamide chain has coil conformation in DMSO at 20 °C.

Spontaneous platelet aggregation in normal subject assessed by a laser light scattering method: An attempt at standardization

Platelet aggregometry by the laser light scattering (LS) method is sufficiently sensitive to detect small platelet aggregates that form spontaneously in vitro in the absence of agonists. Platelet aggregation without agonists is named spontaneous platelet aggregation (SPA). Since SPA has been suggested to be associated with various thrombotic diseases, it is essential to measure SPA and to establish a standard range of SPA values. In this study, we measured SPA in 167 healthy subjects by the LS method and attempted to clarify various factors influencing SPA, including the blood collection procedure. We also attempted to establish a tentative standard range of SPA values. SPA was quantitatively measured in terms of the maximum total LS intensity, which reflects small aggregates formed over 10 minutes (SMAX) and the area under the total LS intensity curve of small aggregates (SAUC). Since both the values of SMAX and SAUC were skewed and the log SMAX and log AUC values showed a normal distribution, the statistical analyses were performed using log SMAX and log SAUC. The log SMAX and log SAUC were significantly higher in the samples collected using a tourniquet and/or a 21 G needle, than in those collected without a tourniquet and/or with an 18 G needle. The log SAUC values were significantly lower in samples obtained with a syringe and/or 3.8% sodium citrate than in those obtained in vacuum sampling tubes and/or 3.13% or 3.14% sodium citrate. The Ht and plasma glucose concentration influenced the log SMAX values. We propose that to standardize SPA measurements, the measurements should be completed within two hours of blood sample collection and collected using the regular concentration of citrate. The standard range of SMAX values measured in samples obtained using a tourniquet and a 21 G needle was 2.0–23.99 (*103 mV*count). The standard range of SAUC values measured under same conditions was 0.58–9.12 (*106 mV*count*min). The standard range of SMAX values measured in samples obtained using a tourniquet, 21 G needle and a vacuum tube was 1.7–29.51 (*103 mV*count). The standard range of SAUC values measured under same conditions was 0.59–9.33 (*106 mV*count*min).

Dynamic Observation of the Behavior of the Surface of Liquid Films of Polymer-Organic Solvent System by Ripplon Surface Laser-Light Scattering Method

リプロン・レーザー表面光散乱法（以下，リプロン法）は強制励起等の外乱付与を行う必要がなく，非接触でかつ高速に，液膜のごく表面の情報を取り出すことが出来るため，表面物性計測において，非常に魅力のある強力な計測ツールである．本研究では，新たに開発したリプロン・レーザー表面光散乱測定装置を用いて，機能性フィルムの製造などで多く用いられるポリマー有機溶剤液の測定を目的に，アセチルブチルセルロース（CAB）ポリマーのメチルエチルケトン（MEK）溶液の表面物性測定を行った．接触式測定法（Wilhelmy Plate法）では，ポリマー濃度を変化させても表面張力に変化が見られないが，リプロン法を使って，数10 kHzの周波数帯域で計測を行ったところ，ポリマー濃度の増加に従って，表面張力が低下していく傾向が見られた．ポリマーの液膜表面への吸着モデルを検討したところ，計測したリプロンの数10 kHzの周波数帯域では，リプロン波の変調速度がCABポリマーが液膜表面に吸脱着する時間に比べ圧倒的に速いために，CABポリマーの表面への吸脱着が間に合わず，あたかも不溶性分子膜のように振舞っていると推定されることがわかった．そのため，CABポリマー濃度，分子量の違いによる液膜表面へのポリマーの吸着量変化が，表面張力の低下と対応して，表面弾性率の変化として観察されることがわかった．よって，この表面弾性率の変化に着目することで，従来は測定困難だった低表面張力，低粘度である低濃度のポリマー有機溶剤液の液膜表面へのポリマーの吸脱着のし易さを計測・評価する新しい手法として活用できると考える．

Monitoring and Predicting Emulsion Stability of Metalworking Fluids by Salt Titration and Laser Light Scattering Method

The prediction of emulsion stability is very important in the study, formulation, quality control, and technical service of metalworking fluids. Conventional emulsion stability test methods can be very time consuming. One quick method to determine emulsion stability is to titrate an emulsion with a salt solution until the emulsion separates. The salt (or electrolyte) concentration at which an emulsion starts to separate is called the critical coagulation concentration (CCC). The higher the CCC value, the more stable the emulsion. Another technique, called laser light scattering method, collects transmission and backscattering light by scanning emulsion samples with a laser. It is a very useful instrument to monitor emulsions and dispersions in kinetic studies of emulsion stability. The response of the laser light scattering method is very sensitive to any change in emulsion or dispersion stability. It has also been utilized in the quick selection of additives in semisynthetic metalworking fluids formulation. Presented at the STLE Annual Meeting in Las Vegas, Nevada, May 15–19, 2005 Review led by Jerry Byers

Development of a Measuring Instrument for Nanoparticles on the Si Wafer Using a Laser Light Scattering Method

The measuring system for particles with diameter of nanometer order sizes on a Si wafer surface using a laser light-scattering method has been developed. To estimate this measuring system, the measurement of a standard particle on a bare Si wafer was attempted and it was verified that this measuring system could measure particle size with a sensitivity of about 24nm. And, the washing for the Si wafer by using a wet cleaning method was attempted to estimate the wet cleaning effect for nanoparticles on its surface. Consequently, it could be verified that the wet cleaning is an effectual method to remove standard nanoparticles of less than diameter of 30nm on Si wafer surface.

Cross-linking of starch with 1, 2, 3, 4-diepoxybutane or 1, 2, 7, 8-diepoxyoctane

Water-soluble and native potato starches were modified with 1, 2, 3, 4-diepoxybutane (DEB) or 1, 2, 7, 8-diepoxyoctane (DEO). Optimal reaction conditions and the effectiveness of the cross-linkers were determined on the basis of yields of water-soluble and insoluble material. The presence of the introduced groups was confirmed by NMR spectroscopy in solution as well as in solid state. According to multi-angle laser light-scattering method, the weight average molecular masses of the water-soluble fractions prepared from water-soluble starch were larger ( M w=471 kDa using DEB; M w=931 kDa with DEO) in comparison with the starting material ( M w=291 kDa). Due to high molecular mass only new anomeric signals were observed by 1H NMR in solution. Maximal yields of insoluble parts were 18 or 50% for DEB or DEO. On native starch the yields of insoluble products decreased with increasing concentration of cross-linker and NaOH in comparison to unmodified material. Solubilized components were dialyzed and we suppose that starch was degraded under these conditions. This material is not suitable for the modification when the goal is to increase the yield of insoluble part. With water-soluble starch the initial first order rate constants of cross-linking with E, DEB and DEO were determined with rheometer. From the relation of complex shear modulus and time by linear regression method at 20–70 °C, first-order rate constants of the same order of magnitude were calculated. The corresponding activation energies of the process are decreasing in the order: E (131 kJ/mol) >DEO (105 kJ/mol) >DEB (55 kJ/mol). We consider these results in agreement with the differences in the structure of the cross-linkers and the mechanism of cross-linking. Both cross-linkers gave spherical particles when cross-linked by the water-in-oil emulsion method with dimensions 60–610 (10%≤192; 50%≤294; 90%≤425) μm, when cross-linked with DEB or 250–730 (10%≤278; 50%≤392; 90%≤548) μm, when DEO was used.

Platelet dysfunction in acute type A aortic dissection evaluated by the laser light-scattering method

ObjectivesPlatelet dysfunction contributes to bleeding tendency in acute type A aortic dissection. Particle counting by new laser light-scattering methods more accurately quantifies changes in the number of different-sized platelet aggregates than do conventional optical density methods. We studied platelet aggregation kinetics and patterns of aggregation deficiency in acute-phase aortic dissection with laser light scattering. MethodsBlood from 20 acute type A aortic dissection patients undergoing surgery was sampled during acute (9.1 ± 6.8 hours from onset) and chronic (postoperative day 20, control) phases of aortic dissection. Platelet count and aggregability were assessed by optical density and laser light-scattering methods after aggregation was induced (addition of 2.0 μg/mL collagen to samples). ResultsOptical density showed significant reduction in acute-phase platelet aggregation (acute vs chronic: 65 ± 27% vs 77 ± 17%, P < .03). Laser light scattering showed significant reduction in medium (25-50 μm) and large (50-70 μm) but not small aggregate (9-25 μm) generation (acute vs chronic: small, 1.2 ± 0.6 × 107 vs 1.5 ± 1.0 × 107, NS; medium, 0.6 ± 0.3 × 107 vs 1.1 ± 0.5 × 107, P < .001; large, 1.4 ± 1.2 × 107 vs 2.6 ± 1.7 × 107, P < .001). Acute- versus chronic-phase platelet counts were significantly decreased (1.7 ± 0.1 × 105/μL vs 3.6 ± 0.3 × 105/μL, P < .001). ConclusionsPlatelet aggregation is suppressed in acute-phase aortic dissection. This suppression does not occur in the initial phase of small aggregate formation; rather, it occurs during the conglomeration of small aggregates into larger aggregates.

Hematologic study of urinary and blood erythrocytes to identify the source of hematuria using a flow cytometer-based laser light-scattering method

Hematologic study of urinary and blood erythrocytes to identify the source of hematuria using a flow cytometer-based laser light-scattering method

Evaluation of size distribution of starch granules in selected wheat varieties by the Low Angle Laser Light Scattering method

&amp;nbsp; &amp;nbsp; The distribution of the size of wheat starch granules using the method LALLS (Low Angle Laser Light Scattering), followed by the evaluation of the effect of variety, experimental site and intensity of cultivation on the vol. % of the starch A (starch granules &amp;gt; 10 &amp;mu;m) was determined. The total starch content and crude protein content in dry matter of flour T530 in selected collection of five winter wheat varieties were determined. Vol. % of the starch A in evaluated collection of wheat varieties varied between 65.31 and 72.34%. The effect of a variety on the vol. % of starch A seemed to be more marked than the effect of site and intensity of cultivation. The highest vol. % of starch A reached evaluated varieties from the quality group C, i.e. varieties unsuitable for baking utilisation (except variety Contra with high total content of starch in dry matter of flour T530, but relatively low vol. % of starch A). A low vol. % of starch A was also found in the variety Hana (very good variety for baking utilisation). Certain variety differences followed from the evaluation of distribution of starch fractions of starch granules, forming starch A. In the case of varieties Hana, Contra and Siria higher representation of fractions up to 30 &amp;mu;m was recorded, while starch A in the varieties Estica andVersailleswas formed in higher degree by size fractions of starch granules over 30 &amp;mu;m and particularly size fraction &amp;gt; 50 &amp;mu;m was greatest in these varieties of all evaluated samples. With increasing total starch content in dry matter of flour T530 the crude protein content decreased; the vol. % of starch A not always increased proportionally with increasing total starch content.

Platelet aggregation in patients taking anticoagulants after valvular surgery: evaluation by a laser light-scattering method

The effects of anticoagulants in the early phase of platelet aggregation in patients with an artificial cardiac prosthesis are unclear. Newly developed particle-counting methods that employ light scattering (LS) can be used to quantify changes in the number of platelet aggregates of different sizes after administration of an aggregating stimulus. Using an LS method, we studied the effects of warfarin and aspirin on aggregation in patients with an artificial cardiac prosthesis. Forty-seven patients undergoing valvular surgery were divided into two groups: 25 patients were treated with warfarin alone (group 1), and 22 patients were treated with both warfarin and aspirin (81 mg/day) (group 2). The international normalized ratio (INR) value was controlled at 2.0–2.5 in both groups. Blood samples were obtained before surgery to obtain control values and on days 21 through 27 after surgery. Platelet aggregation was evaluated after administration of 2.0 μg/ml collagen: small (9–25 μm), medium (25–50 μm), and large (50–70 μm) aggregates were counted. Particle counting by the LS method showed no inhibition of platelet aggregation in group 1 (warfarin alone). The conventional optical density (OD) method yielded a similar result. In group 2 (warfarin plus aspirin), the LS method showed that generation of large aggregates after stimulation was significantly decreased versus presurgery (P = 0.046), whereas the quantity of small aggregates was increased (P = 0.003). The OD methods showed aggregation to be significantly decreased in this group (P < 0.001). Our findings suggest that warfarin does not appear to suppress platelet aggregation. Although aspirin appears to suppress platelet function, it does not affect the initial phase of aggregation. Platelet dysfunction caused by aspirin is due mainly to inhibition of the development of small aggregates into larger aggregates.

B171 電解アルカリ性水の表面張力 : 表面光散乱法による電解過程の動的測定

B171 電解アルカリ性水の表面張力 : 表面光散乱法による電解過程の動的測定

Platelet damage caused by the centrifugal pump: laser-light scattering analysis of aggregation patterns.

Platelets are damaged by shear force during centrifugal pumping; however, the mechanism of this damage has not been fully investigated. A new laser-light scattering (LS) assay method enables quantification of real-time changes in the number of platelet aggregates of different sizes. Using this method, we assessed the kinetics of platelet damage caused by the centrifugal pump from the standpoint of platelet aggregation capacity. Conventional optical density (OD) and LS methods were used to measure platelet aggregation with a Kowa AG-10 aggregometer. Platelet aggregation in fresh human blood was evaluated in a mock circuit for 3 h under a flow rate of 5.0 L/min and a pressure head of 100 mm Hg. Test samples were obtained before pumping for control, and at 1, 2, and 3 h after the start of pumping. The test series was begun 8 times. Aggregation after stimulation by 2.0 microg/ml collagen was determined; small (9 to 25 microm), medium (25 to 50 microm), and large (50 to 70 microm) aggregates were counted by the LS method. OD measurement at hourly intervals showed significant reduction in platelet aggregation. The LS method showed that generation of small and medium aggregates was not suppressed during pumping, but that generation of large aggregates was significantly reduced at 2 and 3 h of pumping. Platelet aggregation is significantly suppressed during centrifugal pumping, and the resulting platelet dysfunction is due mainly to inhibited development of small aggregates into larger aggregates.

The Prognostic Value of Small-Sized Platelet Aggregates in Unstable Angina: Detection by a Novel Laser-Light Scattering Method

Platelet activation plays a pivotal role in the pathogenesis of acute coronary syndromes. This study was designed to evaluate the platelet aggregability in patients with unstable angina using a new aggregometer with laser-light scattering. We also examined whether there was a relationship between these platelet aggregabilities and unfavorable outcome during in-hospital stay. We measured platelet aggregability, in particular small-sized platelet aggregates in 31 patients with unstable angina, 31 patients with stable exertional angina, and 30 patients with chest pain syndrome. The patients with unstable angina were divided into two groups by their cardiac events during in-hospital stay, cardiac events (+)( n=11) group and cardiac events (−)( n=20) group. On admission, the number of small-sized platelet aggregates ( V) was higher in patients with unstable angina (3.0±0.5×10 4) than in those with stable exertional angina (1.4±0.3×10 4, P=.017) and chest pain syndrome (0.7±0.2×10 4, P=.0003). The number of small-sized platelet aggregates was higher in the cardiac events (+) group than in the cardiac events (−) group (5.5±0.9×10 4 vs. 1.6±0.4×10 4, P=.0001). A previous study elucidated that small-sized platelet aggregates ultimately developed into medium-sized and large-sized aggregates as platelet aggregation proceeds. Therefore, the production of small-sized platelet aggregates is more sensitive for hyperaggregability. Furthermore, the production of small-sized platelet aggregates increased significantly in patients with unstable angina than in those with stable exertional angina and chest pain syndrome. These findings suggest that a tendency toward thrombus formation increases markedly in patients with unstable angina and increased number of small-sized platelet aggregates on admission predicts poor prognosis during in-hospital stay in patients with unstable angina.