Semiconducting Electronic Structure of the Ferromagnetic Spinel HgCr_{2}Se_{4} Revealed by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy

We study the electronic structure of the ferromagnetic spinel HgCr_{2}Se_{4} by soft-x-ray angle-resolved photoemission spectroscopy (SX-ARPES) and first-principles calculations. While a theoretical study has predicted that this material is a magnetic Weyl semimetal, SX-ARPES measurements give direct evidence for a semiconducting state in the ferromagnetic phase. Band calculations based on the density functional theory with hybrid functionals reproduce the experimentally determined band gap value, and the calculated band dispersion matches well with ARPES experiments. We conclude that the theoretical prediction of a Weyl semimetal state in HgCr_{2}Se_{4} underestimates the band gap, and this material is a ferromagnetic semiconductor.

A Noise-Robust Data Assimilation Method for Crystal Structure Determination Using Powder Diffraction Intensity

Crystal structure prediction for a given chemical composition has long been a challenge in condensed-matter science. We have recently shown that experimental powder X-ray diffraction (XRD) data are helpful in a crystal structure search using simulated annealing, even when they are insufficient for structure determination by themselves (N. Tsujimoto et al., Phys. Rev. Materials 2, 053801 (2018)). In the method, the XRD data are assimilated into the simulation by adding a penalty function to the physical potential energy, where we used a crystallinity-type penalty function defined by the difference between experimental and simulated diffraction angles. To improve the success rate and noise robustness, we introduce a correlation-coefficient-type penalty function adaptable to XRD data with significant experimental noise. We apply the new penalty function to SiO2 coesite and ε-Zn(OH)2 to determine its effectiveness in the data assimilation method.

First-Principles Study of the Optical Dipole Trap for Two-Dimensional Excitons in Graphane

Recent studies on excitons in two-dimensional materials have been widely conducted for their potential usages for novel electronic and optical devices. Especially, sophisticated manipulation techniques of quantum degrees of freedom of excitons are in demand. In this Letter we propose a technique of forming an optical dipole trap for excitons in graphane, a two-dimensional wide gap semiconductor, based on first-principles calculations. We develop a first-principles method to evaluate the transition dipole matrix between excitonic states and combine it with the density functional theory and GW+BSE calculations. We reveal that in graphane the huge exciton binding energy and the large dipole moments of Wannier-like excitons enable us to induce the dipole trap of the order of meV depth and μm width. This Letter opens a new way to control light-exciton interacting systems based on newly developed numerically robust ab initio calculations.

Anomalous High-Temperature Superconductivity in YH6

Pressure-stabilized hydrides are a new rapidly growing class of high-temperature superconductors, which is believed to be described within the conventional phonon-mediated mechanism of coupling. Here, the synthesis of one of the best-known high-T_C superconductors-yttrium hexahydride I m 3 ¯ m -YH₆ is reported, which displays a superconducting transition at ≈224 K at 166 GPa. The extrapolated upper critical magnetic field B_c2 (0) of YH₆ is surprisingly high: 116-158 T, which is 2-2.5 times larger than the calculated value. A pronounced shift of T_C in yttrium deuteride YD₆ with the isotope coefficient 0.4 supports the phonon-assisted superconductivity. Current-voltage measurements show that the critical current I_C and its density J_C may exceed 1.75 A and 3500 A mm^-2 at 4 K, respectively, which is higher than that of the commercial superconductors, such as NbTi and YBCO. The results of superconducting density functional theory (SCDFT) and anharmonic calculations, together with anomalously high critical magnetic field, suggest notable departures of the superconducting properties from the conventional Migdal-Eliashberg and Bardeen-Cooper-Schrieffer theories, and presence of an additional mechanism of superconductivity.

Oxalate and silica contents of seven varieties of Napier grass (Pennisetum purpureum)

Oxalate and silica are considered antinutrients. Large quantities of oxalate and silica in plants can interfere with the uptake of essential minerals in ruminants. Therefore, the aim of this study was to compare the total silica and oxalate contents of seven varieties of Napier grass to find out which is best for cultivation. Taiwan, Zanzibar, Pakchong, Purple, Kobe, Indian, and Dwarf Napier grass were grown in a completely randomized design with three replications to determine their soluble oxalate, total oxalate, and silica contents. Plants were harvested at two months of plant maturity. Whole plant of the Dwarf Napier grass contained significantly higher soluble oxalate content than tall varieties. Total oxalate content in whole plant differed significantly among varieties. Dwarf showed the highest total oxalate content (3.23% dry matter (DM)) followed by Kobe (2.61%), Zanzibar (2.60%), Purple (2.44%), Taiwan (2.43%), Indian (2.15%), and Pakchong (1.95%). Regardless of variety, leaf tissue contained significantly higher soluble oxalate and total oxalate than stem tissue. There were no differences in silica content among them. In conclusion, the tall varieties could produce lower levels of soluble oxalate than the Dwarf variety, whereas silica content might not vary among them.Keywords: botanical fractions, mineral bioavailability, ruminant

P6405Potential for drug-drug interaction between vonoprazan and prasugrel on antiplatelet effect assessed by VerifyNow P2Y12 assay in patients with coronary artery disease

Background

Vonoprazan is a potassium-competitive acid blocker increasingly used in Japan to prevent gastrointestinal bleeding in patients under dual antiplatelet therapy (DAPT) after coronary stents implantation. Since cytochrome P450 (CYP) 3A4 is involved in the primary metabolism of vonoprazan and prasugurel, there is a possibility that CYP-mediated drug-drug interaction between them can attenuate the antiplatelet function of prasugrel.

Purpose

The aim of this study was to investigate whether antiplatelet effect of prasugrel could be attenuated upon coadministration with vonoprazan compared to conventional proton pump inhibitors (PPIs).

Method

We evaluated 72 patients (57 males, 67±11 years) with coronary artery disease who were taking either vonoprazan (n=35) or PPIs (n=37) in combination with DAPT (aspirin and prasugrel) after drug-eluting stents implantation. PPIs included 21 esomeprazole, 8 lansoprazole, and 8 rabeprazole. Antiplatelet effects of prasugrel were assessed using VerifyNow P2Y12 assay. Primary measurements were P2Y12 reaction units (PRU) and P2Y12 percent inhibition. High on-treatment platelet reactivity (HPR) on prasugrel was defined as PRU >208. Administration period of vonoprazan or PPIs in combination with DAPT ≤7 days was defined as early administration period.

Results

Median administration period of vonoprazan or PPIs in combination with DAPT was 127 days. There were no significant differences in baseline clinical characteristics between patients with vonoprazan and PPIs. In the analysis for all subjects, patients with vonoprazan showed similar PRU (166±50 vs. 167±64, p=0.93) and percent inhibition (36±18 vs. 38±23, p=0.66) compared to those with PPIs. No significant differences were observed in the prevalence of HPR between patients with vonoprazan and PPIs (17 vs. 30%, p=0.27). In the analysis for patients in early administration period [vonoprazan (n=14) vs. PPIs (n=10)], there were no significant differences in PRU (166±47 vs. 186±82, p=0.45), percent inhibition (33±17 vs. 30±26, p=0.73), and prevalence of HPR (14 vs. 50%, p=0.085) between patients with vonoprazan and PPIs. In addition, the analysis for patients over early administration period [vonoprazan (n=21) vs. PPIs (n=27)] showed that PRU (166±55 vs. 160±57, p=0.73), percent inhibition (37±19 vs. 41±21, p=0.57), and prevalence of HPR (19 vs. 22%, p=1.00) were comparable between patients with vonoprazan and PPIs.

Conclusion

Compared to PPIs, vonoprazan did not exhibit significant inhibitory effects on the antiplatelet activity of prasugrel assessed by VerifyNow assay. These findings suggest that there are possibly no clinically harmful drug-drug interactions between vonoprazan and prasugrel.

P1549Serum soluble Klotho is associated with extent of coronary artery calcification in patients with stable angina pectoris undergoing percutaneous coronary intervention

Background

Klotho, which was originally identified as an aging suppressor, is a key regulator of bone and mineral metabolism. Transmembrane and soluble forms of Klotho protein have been identified. The transmembrane form serves as an obligate co-receptor for fibroblast growth factor 23 (FGF23). However, the physiological importance of soluble form of Klotho has not been determined.

Purpose

The present study aimed to test the hypothesis that circulating soluble Klotho levels can predict the presence or extent of coronary artery calcification (CAC) in patients with coronary artery disease.

Methods

We analyzed CAC of culprit lesions in patients with 75 stable angina pectoris who were not on dialysis and were scheduled for percutaneous coronary intervention (PCI) following intravascular ultrasound (IVUS). Arc and length of each calcium within the culprit lesion was measured by IVUS. The main outcome measure was the calcium index; a volumetric IVUS-derived measure which was calculated as total calcium length/lesion length × maximal calcium arc/360°. Low calcium index was defined as calcium index <0.042 of the first quartile value. Serum Klotho and FGF23 were measured before PCI. Patients were divided into two groups according to median serum Klotho value: low-Klotho (n=37, ≤460 pg/mL) and high-Klotho group (n=38, >460 pg/mL).

Results

Compared with patients with low-Klotho, those with high-Klotho had higher estimated glomerular filtration rate (eGFR) (69±20 vs. 55±16 mL/min/1.73 m2, p<0.001), lower FGF23 levels (51±24 vs. 67±41 pg/mL, p=0.010). Patients with high-Klotho had significantly lower calcium index than those with low-Klotho (0.17±0.21 vs. 0.24±0.23, p=0.043). Serum Klotho levels correlated significantly and inversely with calcium index (r=−0.31, p=0.006). The correlation between Klotho and calcium index was pronounced at analysis in patients with eGFR <60 mL/min/1.73 m2 (r=−0.52, p<0.001). Logistic regression analysis showed that high-Klotho is a sole significant independent factor associated with low calcium index (odds ratio 7.17, p=0.004). Presence of high-Klotho had high sensitivity and negative predictive value for identifying low calcium index (83% and 92%, respectively).

Conclusions

Serum Klotho values were independently and inversely associated with the degree of CAC assessed by IVUS. These findings have important clinical implications for serum Klotho as a biomarker that reflects the extent of CAC.

Coulomb Energy Density Functionals for Nuclear Systems: Recent Studies of Coulomb Exchange and Correlation Functionals

The Coulomb exchange and correlation energy density functionals for electron systems are applied to nuclearsystems. It is found that the exchange functionals in the generalized gradient approximation provide agreements with the exact-Fock energy with one adjustable parameter within a few dozen keV accuracy, whereas the correlation functionals are not directly applicable to nuclear systems due to the existence of the nuclear force.

Nonempirical Calculation of Superconducting Transition Temperatures in Light-Element Superconductors

Recent progress in the fully nonempirical calculation of the superconducting transition temperature (T_c ) is reviewed. Especially, this study focuses on three representative light-element high-T_c superconductors, i.e., elemental Li, sulfur hydrides, and alkali-doped fullerides. Here, it is discussed how crucial it is to develop the beyond Migdal-Eliashberg (ME) methods. For Li, a scheme of superconducting density functional theory for the plasmon mechanism is formulated and it is found that T_c is dramatically enhanced by considering the frequency dependence of the screened Coulomb interaction. For sulfur hydrides, it is essential to go beyond not only the static approximation for the screened Coulomb interaction, but also the constant density-of-states approximation for electrons, the harmonic approximation for phonons, and the Migdal approximation for the electron-phonon vertex, all of which have been employed in the standard ME calculation. It is also shown that the feedback effect in the self-consistent calculation of the self-energy and the zero point motion considerably affect the calculation of T_c . For alkali-doped fullerides, the interplay between electron-phonon coupling and electron correlations becomes more nontrivial. It has been demonstrated that the combination of density functional theory and dynamical mean field theory with the ab initio downfolding scheme for electron-phonon coupled systems works successfully. This study not only reproduces the experimental phase diagram but also obtains a unified view of the high-T_c superconductivity and the Mott-Hubbard transition in the fullerides. The results for these high-T_c superconductors will provide a firm ground for future materials design of new superconductors.

Possible "Magnéli" Phases and Self-Alloying in the Superconducting Sulfur Hydride

We theoretically give an infinite number of metastable crystal structures for the superconducting sulfur hydride H_{x}S under pressure. Previously predicted crystalline phases of H_{2}S and H_{3}S have been thought to have important roles for experimentally observed low and high T_{c}, respectively. The newly found structures are long-period modulated crystals where slablike H_{2}S and H_{3}S regions intergrow on a microscopic scale. The extremely small formation enthalpy for the H_{2}S-H_{3}S boundary indicated by first-principles calculations suggests possible alloying of these phases through the formation of local H_{3}S regions. The modulated structures and gradual alloying transformations between them not only explain the peculiar pressure dependence of T_{c} in sulfur hydride observed experimentally, but also could prevail in the experimental samples under various compression schemes.

Aromatic hydrocarbon macrocycles for highly efficient organic light-emitting devices with single-layer architectures

Aromatic hydrocarbon macrocycles for phosphorescent organic light-emitting devices with a single-layer architecture were designed.

A modern electrophosphorescent organic light-emitting device (OLED) achieves quantitative electro-optical conversion by using multiple layers of molecular materials designed through role allotment for independent and specific functions. A unique, potentially innovative device architecture, i.e., a single-layer phosphorescent OLED, is currently being developed by designing multirole base materials via a structural combination of multiple functional components in single molecules. The multirole molecules, however, inevitably require multiple processes to synthesize their multiple components and, moreover, to assemble these components synthetically into one molecule. We herein show that the multirole base material for a highly efficient single-layer phosphorescent OLED can be designed and synthesized with a single, very simple aromatic hydrocarbon component of toluene merely through a one-pot macrocyclization. Without requiring the assembly tasks at the synthesis stage, the molecular design allows for a concise one-pot synthesis of, and a quantitative electro-optical conversion in, the single-layer device architecture with a single-component base material.

Valley-dependent spin polarization in bulk MoS2 with broken inversion symmetry

The valley degree of freedom of electrons is attracting growing interest as a carrier of information in various materials, including graphene, diamond and monolayer transition-metal dichalcogenides. The monolayer transition-metal dichalcogenides are semiconducting and are unique due to the coupling between the spin and valley degrees of freedom originating from the relativistic spin-orbit interaction. Here, we report the direct observation of valley-dependent out-of-plane spin polarization in an archetypal transition-metal dichalcogenide--MoS2--using spin- and angle-resolved photoemission spectroscopy. The result is in fair agreement with a first-principles theoretical prediction. This was made possible by choosing a 3R polytype crystal, which has a non-centrosymmetric structure, rather than the conventional centrosymmetric 2H form. We also confirm robust valley polarization in the 3R form by means of circularly polarized photoluminescence spectroscopy. Non-centrosymmetric transition-metal dichalcogenide crystals may provide a firm basis for the development of magnetic and electric manipulation of spin/valley degrees of freedom.

Development of density-functional theory for a plasmon-assisted superconducting state: application to lithium under high pressures

We extend the density-functional theory for superconductors (SCDFT) to take account of the dynamical structure of the screened Coulomb interaction. We construct an exchange-correlation kernel in the SCDFT gap equation on the basis of the random-phase approximation, where electronic collective excitations such as plasmons are properly treated. Through an application to fcc lithium under high pressures, we demonstrate that our new kernel gives higher transition temperatures (T(c)) when the plasmon and phonon cooperatively mediate pairing and it improves the agreement between the calculated and experimentally observed T(c). The present formalism opens the door to nonempirical studies on unconventional electron mechanisms of superconductivity based on density-functional theory.

A case of lupus erythematosus profundus with multiple arc-shaped erythematous plaques on the scalp and a review of the literature

A 26-year-old Japanese female presented to us with a 2-year history of multiple arc-shaped erythematous lesions on her scalp and the right side of her forehead. Histopathological examination of two of the lesions showed lobular and septal panniculitis with deposits of IgG in the basement membrane zone. We diagnosed the case as lupus erythematosus profundus, and successfully treated her with 20 mg/day prednisolone. To our knowledge, there has been only one previously reported case of lupus erythematosus profundus with annular-shaped erythematous lesions and six cases with linear configuration.

Pancreatic sphincter precutting to gain selective access to the common bile duct: a series of 172 patients

BACKGROUND AND STUDY AIMS

Several precutting techniques have been described in cases of failed access to the common bile duct. We describe our experience with pancreatic sphincter precutting in an upward direction, and report its success rates and complications.

PATIENTS AND METHODS

A total of 172 patients underwent a procedure using this technique between January 1989 and December 2001. The technique consisted of a medium-to-large precut along the midline, above the papillary elevation, using either the common channel or the pancreatic duct in the ampulla of Vater as a guide. The septum between the pancreatic duct and the bile duct was removed and separate openings to the pancreatic and bile ducts were created, followed by complete biliary sphincterotomy.

RESULTS

Biliary cannulation and sphincterotomy was successful in 163 of the 172 study patients (95 %). Mild complications, which were all managed conservatively, occurred in 17 patients (10 %). This complication rate was significantly higher than our complication rate for standard endoscopic sphincterotomy, which was 0.8 % in 1770 patients ( P < 0.0001).

CONCLUSIONS

Pancreatic sphincter precutting is an effective and safe technique for patients in whom selective cannulation of the common bile duct has failed. Further prospective comparative studies of other precutting techniques will better define its clinical value.

[A case of percutaneous and transpapillary placements of expandable metallic stents in a patient with cholangiocarcinoma at the hilum of the liver]

A 76-year-old woman was admitted with obstructive jaundice. US and MR cholangiopancreatography (MRCP) revealed an inoperative cholangiocarcinoma, 3 cm in diameter at the hilum of the liver, the obstruction of the hepatic duct bifurcation and the separation of bilateral hepatic bile ducts. Percutaneous transhepatic biliary drainage (PTBD) was performed from bilateral hepatic bile ducts. The right PTBD tube was spontaneously extubated. We could not succeed in performing internal biliary drainage across the hilar malignant stricture from a left hepatic bile duct, because of bad angulation. Transpapillary insertion into the common bile duct (CBD) was extremely difficult due to the collapse of the CBD. Endoscopic sphincterotomy (EST) after precutting method was performed. Although we performed the ballooned dilatation of malignant stricture and the insertion of a self-expandable metallic stent (EMS) into a right hepatic bile duct transpapillary. After dilatation of the hilar malignant stricture by the initial EMS, we inserted a guidewire into the CBD through the wire mesh of a stent from the left PTBD tube. We could insert the second EMS from a left hepatic bile duct to the CBD transhepatically, using a dilator and a dilating balloon. Finally, we performed the ballooned dilatation from bilateral hepatic bile ducts to the CBD transpapillary. She was discharged after bilateral internal biliary drainages, successfully.

[An extremely elderly patient with choledocholithiasis and many complications]

It was very difficult to treat a 90-year-old woman for choledocholithiasis with acute obstructive suppurative cholangitis, gallbladder perforation, and a pool of bile in the right perirenal spase. Extracorporeal shockwave lithotripsy (ESWL) was performed after emergency percutaneous transhepatic biliary drainage (PTBD), but we could not perform lithotripsy successfully because of large and hard stones. Although Endoscopic sphincterotomy (EST) was performed using an ultratome by rendezvous method. Lithotripsy was finally successful, after three times endoscopic mechanical lithotripsy (EML) and procedure using an endotriptor for basket impaction. It is very important in advanced aged patients that endoscopic treatment should be performed step by step.

[An elderly case of post-bulbar Dieulafoy's ulcer]

The case is a 79-year-old man who came to our hospital with melena as chief complaint. Emergency endoscopy showed spurting bleeding from a small ulcer. We diagnosed as Post-Bulbar Dieulafoy's ulcer and performed hemostatic procedure with hemostatic clips. The forth endoscopy (7 days after admission) showed fresh clot and oozing bleeding after the third hemostatic clipping. Although we performed hemostatic procedure with the injection therapy of hypertonic saline epinephrine solution (HSE). The effective hemostatic procedure is discussed with reference to some related literature.

[Surgical treatment of secondary chronic colonic pseudo-obstruction]

A 74-year-old woman was admitted to the hospital because of constipation and marked abdominal distension. She had become to be bedridden after cerebral infarction 10 years previously, and was tabescent due to vomiting. A left hemicolectomy and colostomy were performed because conservative therapy seemed to be ineffective. The postoperative course was good and her nutritional status improved.

[A case of endocrine cell carcinoma in the duodenal bulb]

A 73-year-old man was admitted to our hospital due to weight loss and melena. Roentgenograms and endoscopy showed a Borrmann type 2 tumor occupying the entire duodenal bulb. Histological findings of the lesion (H-E stain) showed poorly differentiated adenocarcinoma. Almost the entire specimen showed positive staining granules for Grimelius stain. Ultrastructurally, remarkable endocrine granules covered a layer of the limited membrane (membrane-bound granule) in the tumor cell. We diagnosed endocrine cell carcinoma. Since it was difficult to operate due to age and invasion to the fundus of the gall-bladder and the pancreatic head, we treated this case by chemotherapy.

[A case of Lemmel's syndrome caused by a large diverticular enterolith at the peripapillary portion of the duodenum]

A 93-year-old woman admitted because of epigastralgia. Cholelithiasis, obstructive jaundice, acute suppurative cholangitis and acute pancreatitis were diagnosed on blood chemistry and ultrasonography on admission. We performed emergency PTCD. A calculus 4 cm in diameter was detected at the papilla of Vater and marked dilatation of the common bile duct and pancreatic duct. ESWL was performed because of her age and because endoscopical operation seemed to be difficult. After lithotripsy, PTC and endoscopy demonstrated a diverticulum at the peripapillary portion of the duodenum. Based on analysis of PTC result before and after ESWL, we diagnosed this case as Lemmel's syndrome (obstructive jaundice, acute suppurative cholangitis and acute pancreatitis) caused by a large diverticular enterolith at the peripapillary portion of the duodenum. ESWL treatment of aged patient with an enterolith is safe.

[A case of early duodenal cancer resected by endoscopic polypectomy in the elderly]

Early duodenal cancer has been detected with increasing frequency of endoscopy and the advent of an aging society. Aged patients, however, are often inoperable because of complications due to various underlying diseases. The authors report a case of early duodenal cancer curatively operated by endoscopic polypectomy and refer to related cases in the literature.

[Upper gastrointestinal bleeding in the elderly]

Due to increasing number of the elderly, cases of hematemesis and melena in the aged have been increasing. The authors evaluated 69 such cases over 60 years old in whom emergency endoscopy of the upper digestive tract was carried out because of hematemesis and melena. Twenty cases are diagnosed as gastric ulcer (29%), 12 cases as esophageal ulcer and esophageal erosion (17.4%), 9 as duodenal ulcer (13.0%), 7 as gastric cancer (10.1%), 6 as Mallory-Weiss syndrome (8.7%), 6 as esophageal and gastric varices (8.7%), 4 as acute hemorrhagic gastritis (5.8%), 3 as Dieulafoy's ulcer (4.3%), and one case each of chronic pancreatitis (hemosuccus pancreaticus) and hemorrhage due to gastric angiodysplasia (1.4%). Of these cases, blood transfusion was performed in 46 cases (66.7%), and shock occurred in 27 cases (39.1%). The endoscopical hemostatic procedure was effective for detection of underlying diseases in the aged. Surgery was often impossible because of the rapid deterioration of the systemic condition due to the hemorrhage of the digestive tract.

Light-inducible pigmentation in Portulaca callus; selection of a high betalain producing cell line

We have established a unique betalain pigmentation system in callus cultures that originated from seedlings of Portulaca sp. 'Jewel'. Within three different 'Jewel' lines examined, one line (JR) was clearly superior with regard to callus growth rate and pigment formation. Furthermore, after ten cycles of selection of deeply colored callus patches, the selected clones contained on an average four times the amount of betalain as compared to the non-selected mother line. The colorization was induced by light, but disappeared in the dark. Pigment synthesis was detectable within 30 h after irradiation and showed positive correlation with irradiation periods.

Low-friction hydrophilic surface for medical devices

A hydrophilic polymer surface was developed exhibiting excellent low frictional property, namely slipperiness, when in contact with water or physiological fluid due to the reaction of epoxy-containing poly(vinyl pyrrolidone) with the polyamino compound formed on the surface of the substrate. Epoxy-containing poly(vinyl pyrrolidone) was obtained by the copolymerization of vinyl pyrrolidone as a hydrophilic component, glycidyl acrylate as a binding component to the substrate, and vinyl acetate to preserve the strength of the coating layer. The surface friction coefficient depends on the molecular weight of the coated hydrophilic copolymer. It was demonstrated that a molecular weight of 400,000 or more is essential to achieve excellent low surface friction. Using rabbit models, polyurethane catheters, both with and without the hydrophilic low friction coating, were evaluated for surface friction coefficient and blood compatibility. As a result, in the case of coated catheters, no lesions of the intima of the blood vessels and no thrombus formations on the surfaces of the catheters were observed. However, the non-coated catheters injured the intima of the blood vessels and severe thrombus formation was found on their surfaces.