Numerical analysis on a viewing angle enhancement of a digital hologram by attaching a pixelated random phase mask.

In a digital hologram, the maximum viewing angle of a computer-generated hologram (CGH) is limited by pixel pitch due to the diffraction grating equation. Since reducing pixel size of display panel is challenging and costly, we propose a method to expand the viewing angle of a digital hologram by attaching an aligned pixelated random phase mask (PRPM) onto the CGH pattern based on analysis of simulation results. By introducing a phase-averaging process to the widely used iterative Fourier transform algorithm, an optimized CGH pattern can be obtained in conjunction with a PRPM. Based on scalar diffraction theory, viewing angle enhancement characteristics were verified by comparing the perspective views of a two-plane hologram using a virtual eye model. In addition, we performed full electromagnetic simulations that included effects due to potential fabrication errors such as misalignment, thickness variation, and internal reflections and diffractions between the CGH and random mask patterns. From the simulation results, by attaching a 1.85 µm-sized pixel pitch PRPM to a 3.7 µm CGH, the viewing angle can be easily expanded almost identical to that of a CGH with 1.85 µm-pixel pitch.

Formation of ferromagnetic Co-H-Co complex and spin-polarized conduction band in Co-doped ZnO.

Magnetic oxide semiconductors with wide band gaps have promising spintronic applications, especially in the case of magneto-optic devices. Co-doped ZnO (ZnCoO) has been considered for these applications, but the origin of its ferromagnetism has been controversial for several decades and no substantial progress for a practical application has been made to date. In this paper, we present direct evidence of hydrogen-mediated ferromagnetism and spin polarization in the conduction band of ZnCoO. Electron density mapping reveals the formation of Co-H-Co, in agreement with theoretical predictions. Electron spin resonance measurement elucidates the ferromagnetic nature of ZnCoO by the formation of Co-H-Co. We provide evidence from magnetic circular dichroism measurements supporting the hypothesis that Co-H-Co contributes to the spin polarization of the conduction band of hydrogen-doped ZnCoO.

A randomized clinical trial comparing long-term clopidogrel vs aspirin monotherapy beyond dual antiplatelet therapy after drug-eluting coronary stent implantation: Design and rationale of the Harmonizing Optimal Strategy for Treatment of coronary artery stenosis-Extended Antiplatelet Monotherapy (HOST-EXAM) trial.

Percutaneous coronary intervention (PCI) has been developed by drug-eluting stent (DES), but stent implantation has brought the issue of stent thrombosis and optimal antiplatelet therapy. Guidelines recommend at least 6- to 12 months of dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor such as clopidogrel. Beyond DAPT after PCI with DES, however, there has been still a debate for antiplatelet regimen. Therefore, we report on the upcoming HOST-EXAM trial (NCT02044250), which will evaluate the efficacy and safety of aspirin and clopidogrel monotherapies beyond DAPT after DES implantation. TRIAL DESIGN: The HOST-EXAM is a prospective, randomized, open-label, multicenter, comparative effectiveness trial, to compare between clopidogrel (75 mg once daily) and aspirin (100 mg once daily) as long-term antiplatelet agents. A total of 5,530 patients with no clinical events during combined antiplatelet therapy for 12±6 months after index PCI will be screened, enrolled, and randomized to either group (1:1 ratio) receiving antiplatelet monotherapy for 2 years. The primary endpoint will be the rate of clinical events defined as a composite of all-cause death, nonfatal myocardial infarction, stroke, readmission due to acute coronary syndrome, or major bleeding at 24 months after randomization. CONCLUSIONS: The HOST-EXAM will be the first large-scale randomized controlled study to directly compare the efficacy and safety of long-term antiplatelet monotherapy beyond DAPT after DES implantation. This study will provide clinical evidence to establish optimal regimen for long-term antiplatelet therapy after DES implantation.

Aneurysmal Neck Clipping as the Primary Treatment Option for Both Ruptured and Unruptured Middle Cerebral Artery Aneurysms.

OBJECTIVE: Although middle cerebral artery (MCA) aneurysms are less amenable to coil embolization, an increasing number of studies support favorable endovascular treatment for them. The purpose of this study is to compare the outcomes of two different treatments (surgery versus coiling) and evaluate the benefits of surgical clipping for MCA aneurysms. METHODS: Here we retrospectively analyzed the outcomes of 178 ruptured and unruptured MCA aneurysms treated in patients between September 2008 and April 2012. Parameters assessing treatment outcomes include degree of aneurysm occlusion, presence of regrowth, clinical status, and complications. RESULTS: Among 178 MCA aneurysms, 153 were treated surgically. After a mean follow-up of 12 months, the surgery group showed a clinically significant complete occlusion rate (98%) compared with the coiling group (56%) (p<0.001). Follow-up radiologic evaluation showed a higher regrowth rate (four of 16 cases) in the coiling group than in the surgery group (one of 49 cases) (p=0.003). There was no statistically significant difference in favorable clinical outcome rate between the two groups. The procedure-related permanent morbidity and mortality rates were 2% (three of 153 cases) in the surgery group and 0% (0 of 25 cases) in the coiling group. CONCLUSION: Compared to endovascular treatment, surgical neck clipping for both ruptured and unruptured MCA aneurysms results in a significantly higher complete obliteration rate and less regrowth. Therefore, even in this endovascular era, we still recommend surgical clipping as the primary treatment option for MCA aneurysms rather than coil embolization.

Analysis of oxygen vacancy in Co-doped ZnO using the electron density distribution obtained using MEM.

Oxygen vacancy (VO) strongly affects the properties of oxides. In this study, we used X-ray diffraction (XRD) to study changes in the VO concentration as a function of the Co-doping level of ZnO. Rietveld refinement yielded a different result from that determined via X-ray photoelectron spectroscopy (XPS), but additional maximum entropy method (MEM) analysis led it to compensate for the difference. VO tended to gradually decrease with increased Co doping, and ferromagnetic behavior was not observed regardless of the Co-doping concentration. MEM analysis demonstrated that reliable information related to the defects in the ZnO-based system can be obtained using X-ray diffraction alone.

Characterization of enzymatically modified rice and barley starches with amylosucrase at scale-up production.

Physicochemical properties of Neisseria polysaccharea amylosucrase (NpAS)-treated rice and barley starches were investigated at scale-up production. Pre-gelatinized rice and barley starches were treated with significantly lower NpAS dose (0.1 U/mL) but 100 times larger reaction volume (3500 mL), compared to the analytical scale (35 mL) used in the previous study. NpAS-treated starches in this scale-up production were characterized with respect to reaction efficiency (RE), resistant starch (RS) content, amylopectin (AP) branch-chain length distribution, solubility, swelling power, pasting viscosity, and thermal transition properties. The RE enhanced up to 1.8 times by increasing the reaction volume, which improved the RS content and AP branch-chain lengths of NpAS-treated starches. Compared with the native starch, NpAS-treated starches exhibited lower solubility and swelling power, lower pasting viscosity, and a large increase in the melting peak temperature. Consequently, NpAS treatment of pre-gelatinized starches in this study would be a potential way of replacing commercial RS production.

Fabrication of high-quality single-crystal Cu thin films using radio-frequency sputtering.

Copper (Cu) thin films have been widely used as electrodes and interconnection wires in integrated electronic circuits, and more recently as substrates for the synthesis of graphene. However, the ultra-high vacuum processes required for high-quality Cu film fabrication, such as molecular beam epitaxy (MBE), restricts mass production with low cost. In this work, we demonstrated high-quality Cu thin films using a single-crystal Cu target and radio-frequency (RF) sputtering technique; the resulting film quality was comparable to that produced using MBE, even under unfavorable conditions for pure Cu film growth. The Cu thin film was epitaxially grown on an Al2O3 (sapphire) (0001) substrate, and had high crystalline orientation along the (111) direction. Despite the 10(-3) Pa vacuum conditions, the resulting thin film was oxygen free due to the high chemical stability of the sputtered specimen from a single-crystal target; moreover, the deposited film had >5× higher adhesion force than that produced using a polycrystalline target. This fabrication method enabled Cu films to be obtained using a simple, manufacturing-friendly process on a large-area substrate, making our findings relevant for industrial applications.

Resorption of bone graft after maxillary sinus grafting and simultaneous implant placement.

OBJECTIVES: The purpose of this study was to evaluate the sinus bone graft resorption over 3 years after two-stage implant placement. MATERIALS AND METHODS: The subjects for this study included 30 patients whose maxillary posterior ridges were too atrophic for implants. Bone-added osteotome sinus floor elevation was used in 15 maxillary sinuses, while the bone graft by lateral approach technique was used in 25 maxillary sinuses. The height from the top of the fixture to the sinus floor was estimated immediately after implant placement and the follow-up period was over 3 years. The surgery was classified with two groups: sinus bone grafting with and without autogenous bone. All implants were placed simultaneously. RESULTS: The mean vertical bone loss was 3.15±2.95 mm. The survival rate of implants was 94.7%. CONCLUSION: The amount of bone resorption was not significantly associated with the surgical methods, the type of bone graft materials used, or sinus perforation during surgery.

Fabrication of ZnCoO nanowires and characterization of their magnetic properties.

Hydrogen-treated ZnCoO shows magnetic behavior, which is related to the formation of Co-H-Co complexes. However, it is not well known how the complexes are connected to each other and with what directional behavior they are ordered. In this point of view, ZnCoO nanowire is an ideal system for the study of the magnetic anisotropy. ZnCoO nanowire was fabricated by trioctylamine solution method under different ambient gases. We found that the oxidation of trioctylamine plays an essential role on the synthesis of high-quality ZnCoO nanowires. The hydrogen injection to ZnCoO nanowires induced ferromagnetism with larger magnetization than ZnCoO powders, while becoming paramagnetic after vacuum heat treatment. Strong ferromagnetism of nanowires can be explained by the percolation of Co-H-Co complexes along the c-axis.

The seven-year cumulative survival rate of Osstem implants.

OBJECTIVES: This study was performed to analyze the cumulative survival rate of Osstem implants (Osstem Implant Co., Ltd.) over a seven-year period. MATERIALS AND METHODS: A total of 105 patients who had 467 Osstem implants that were placed at the Section of Dentistry, Seoul National University Bundang Hospital (Seongnam, Korea) from June 2003 through December 2005 were analyzed. The life table method and a cross-tabulation analysis were performed to evaluate the cumulative survival rate. The log rank test was used to evaluate the survival curve. The influence that the prognostic factors had on the survival rate was determined with a Cox proportional hazard model based on logistic regression analysis [corrected]. RESULTS: The seven-year cumulative survival rate of Osstem implants was 95.37%. The Cox proportional hazard model revealed that the following factors had a significant influence on survival rate; increased diameter, reduced prosthetic loading period and performance of bone grafting. CONCLUSION: The osstem implants showed satisfactory results over the seven-year study period.

Effects of amylosucrase treatment on molecular structure and digestion resistance of pre-gelatinised rice and barley starches.

Structural modification of rice and barley starches with Neisseria polysaccharea amylosucrase (NpAS) was conducted, and relationship between structural characteristics and resistant starch (RS) contents of NpAS-treated starches was investigated. Pre-gelatinised rice and barley starches were treated with NpAS. NpAS-treated starches were characterised with respect to morphology, X-ray diffraction pattern, amylopectin branch-chain distribution, and RS content, and their structural characteristics were correlated to RS contents. Regardless of amylose contents of native starches, NpAS-treated (relative to native) starches possessed lower and higher proportions of shorter (DP 6-12) and intermediate (DP 13-36) amylopectin (AP) branch-chains, respectively. RS contents were higher for NpAS-treated starches relative to native starches, and maximum RS contents were obtained for NpAS-treated starches of waxy rice and barley genotypes. Amylose contents were not associated with RS contents of NpAS-treated starches. However, shorter and intermediate AP branch-chain portions were negatively and positively correlated to RS contents of NpAS-treated starches, respectively.

A single dose of esmolol blunts the increase in bispectral index to tracheal intubation during sevoflurane but not desflurane anesthesia.

Activation of the peripheral nerve system by endotracheal intubation is accompanied by an increase in bispectral index (BIS). Esmolol produces a dose-dependent attenuation of the adrenergic response to endotracheal intubation. Desflurane increases sympathetic nerve activity and plasma norepinephrine relative to sevoflurane. The authors hypothesized that esmolol might blunt the BIS response to endotracheal intubation more during sevoflurane anesthesia than desflurane anesthesia. In this double blind, randomized study, after the induction of anesthesia, patients were mask-ventilated with either sevoflurane or desflurane (end-tidal 1 minimum alveolar concentration) and received normal saline or esmolol (0.5 mg/kg) 1 minute before intubation (sevoflurane-control, sevoflurane-esmolol, desflurane-control, and desflurane-esmolol groups, n=20/group). BIS, mean arterial pressure, and heart rate were measured before the induction of anesthesia (awake), before esmolol injection (time point -1), immediately before intubation (time point 0), and every minute for 5 minutes after tracheal intubation (time point 1 to 5). Compared with preintubation, esmolol attenuated the increase in BIS at 1 minute after intubation during sevoflurane anesthesia (5.1% for esmolol and 31.7% for control) but not during desflurane anesthesia (28.6% for esmolol and 30.8% for control). Mean arterial pressure and heart rate increased after intubation in all groups but the changes were greater in the control groups than the esmolol groups. In conclusion, a single dose of esmolol blunted the increase in BIS to tracheal intubation during sevoflurane but not desflurane anesthesia.

Predictors of ineffectual radial arterial pressure monitoring in valvular heart surgery.

BACKGROUND AND AIM OF THE STUDY: Unexpected sustained underestimation of the central aortic pressure by the radial arterial pressure commonly develops following cardiopulmonary bypass (CPB) in valvular heart surgery (VHS), leading to an inappropriate use of vasopressors. The study aim was to identify clinical predictors leading to a sustained inappropriate difference between the radial and femoral arterial pressure (IDRF) in VHS. METHODS: A total of 200 patients undergoing VHS was studied prospectively. Those patients who developed sustained IDRF (systolic IDRF > or =10 mmHg and/or mean IDRF > or =5 mmHg) from immediately after discontinuation of CPB until the end of the surgery were compared with patients who did not develop any IDRF. RESULTS: Data from seven patients who required second aortic cross-clamping and re-CPB were excluded from the analysis; thus, data from 193 patients were analyzed. In total, 53 patients (27.5%) developed sustained IDRF, whereas 80 patients (41.4%) did not develop any IDRF. In multivariate analysis, female gender, the presence of atrial fibrillation and diuretic use were identified as independent preoperative predictors; longer-duration aortic cross-clamping and use of larger amounts of vasopressin during CPB were identified as independent operative risk factors of the sustained IDRF. CONCLUSION: When an erroneously low radial arterial pressure is suspected following CPB in this subset of patients undergoing VHS, monitoring of the femoral or axillary arterial pressure should be considered to guide hemodynamic management, as there is an increased risk of persistence of this phenomenon.

Cardiovascular effects of oral tri-iodothyronine in patients undergoing valvular cardiac surgery.

BACKGROUND: Cardiopulmonary bypass produces a state of functional hypothyroidism characterized by low levels of circulating tri-iodothyronine (T3). Theoretically, supplementing T3 should result in improved hemodynamics as well as patients' outcome. The aim of the present study was to determine whether pretreatment with single oral T3 could prevent serum T3 reduction, and improve hemodynamics and clinical outcome. METHODS: Forty-seven patients undergoing valvular heart surgery were included in the study. Patients were randomly assigned into two groups (T = T group; C = control group) the day before surgery and received single oral T3 40 microg or placebo before operation. Blood samples were collected for determination of serum levels of total T3, T4 and TSH before administration of oral T3 or placebo (baseline), 1, 6 and 18 hour after weaning of cardiopulmonary bypass. Hemodynamic parameters and medication were recorded during the intraoperative period and throughout the first 24 h after arrival at the intensive care unit. RESULTS: T3 levels were significantly higher in the T group 1 hr after weaning of cardiopulmonary bypass. T3 levels in the T group were all maintained within the normal range throughout the study period, whereas it was decreased to below normal level in the C group at 18 hr after weaning of cardiopulmonary bypass. In the T group, vasoactive agent requirements were reduced during and after cardiopulmonary bypass. CONCLUSIONS: Pretreatment with single oral T3 prevented the reduction in T3 level after valvular heart surgery, with subsequent reduction in vasoactive agent requirement.

The differential effects of age on the association of KLOTHO gene polymorphisms with coronary artery disease.

The Klotho knockout mouse is thought to be a good animal model for human aging. Recent studies have reported on the association of KLOTHO gene mutation with cardiovascular disease in humans. We observed the frequencies of single nucleotide polymorphisms, that is, G-395A in the promoter region, C1818T in exon 4, and a functional variant, KL-VS, of KLOTHO gene in Koreans, and we investigated their relationships with the presence of coronary artery disease (CAD) in patients who had undergone coronary angiograms. A total of 274 subjects who underwent coronary angiograms because of chest pain were enrolled, and their blood pressure, body mass index, fasting blood glucose level, and lipid profiles were measured. Genotypings were performed on samples of their blood with real-time polymerase chain reaction. Two single nucleotide polymorphisms, G-395A and C1818T, complied with Hardy-Weinberg equilibrium. For the KL-VS genotype, 1 homozygote subject for the adverse allele was detected among the entire population (GG for F352V and CC for C370S). When the subjects were classified into 4 groups according to the number of stenotic vessels, there were no differences among the mean values of the cardiovascular risk factors, except for age and the fasting blood glucose levels, which showed a significant difference between that of the normal and the diseased vessel groups. There were no differences in the prevalence of CAD according to the genotypes of the G-395A polymorphism; however, for the C1818T polymorphism, those subjects with the T allele showed a lower prevalence of CAD than those with the CC genotype. When the subjects were divided into 2 groups according to age, in the group younger than 60 years, T allele carriers of the C1818T polymorphism showed a lower prevalence of CAD than did the noncarriers. In the group older than 60 years, A allele carriers of the G-395A polymorphism showed a lower prevalence of CAD than did the noncarriers. On the haplotype analysis, the GG-CC haplotype showed an increased risk for CAD with an odds ratio of 2.594 (95% confidence interval, 1.385-4.858; P = 0.003). Differential effects of age were observed in the association of KLOTHO G-395A and C1818T polymorphisms with CAD in Koreans. The KL-VS variant seems to be rarely found in the Korean population. These results infer the possibility of the KLOTHO gene being a candidate gene of atherosclerosis in humans, and further research on this topic needs to be done.

Associations between two single nucleotide polymorphisms of adiponectin gene and coronary artery diseases.

Adiponectin, an adipocyte-secreted protein, is known to have anti-atherogenic, anti-inflammatory and anti-diabetic properties and its serum levels are decreased in obesity, type 2 diabetes, and coronary artery disease. Several studies have been performed to investigate the association of genetic variations in the adiponectin with obesity, insulin resistance, and type 2 diabetes, but few studies were performed in association with coronary artery disease. Therefore we examined the associations between two single nucleotide polymorphisms (SNPs), +45T>G and +276G>T of the adiponectin gene, and coronary artery diseases (CAD). One hundred and fifty six subjects (mean age 57.4 yrs) were enrolled in which coronary angiograms were performed due to chest pain. Genotypings were done for two SNPs in the adiponectin gene by Taqman polymerase chain reaction (PCR) method. The presence of CAD was defined as a >50% reduction of coronary artery diameter. Among 156 subjects, the allele frequencies were 0.683 for G allele and 0.317 for T allele in SNP +276G>T and 0.705 for T allele and 0.295 for G allele in SNP +45T>G. Both genotypes were in compliance with Hardy-Weinberg equilibrium. No association with the presence of CAD was observed for adiponectin gene SNP276 and SNP45 (p = 0.954, p = 0.843). Also, no significant association was observed between the severity of CAD and either SNPs (p = 0.571, p = 0.955). Our study showed that SNP +276G>T and +45T>G in adiponectin gene were not associated with the presence of CAD. Further studies will be necessary to confirm the role of SNP 276G>T and 45T>G in the development of CAD.

Situational syncope induced by belching.

We describe a case of situational syncope induced by belching. The patient showed severe syncope with a high-degree atrioventricular block just after belching, but has not experienced syncope or dizziness over a 3-month follow-up after permanent pacemaker implantation.

Relationship of serum osteoprotegerin levels with coronary artery disease severity, left ventricular hypertrophy and C-reactive protein.

OPG (osteoprotegerin) is an inhibitor of osteoclastogenesis and recent work suggests it has a role in atherosclerosis. Therefore we measured serum OPG levels in patients with coronary artery disease, compared the serum OPG levels among the different groups according to the number of stenotic vessels and determined whether there was any correlation with aortic calcification, LV (left ventricular) mass index and serum CRP (C-reactive protein) levels. Subjects (n=100; mean age, 57 years) who underwent coronary angiograms were enrolled. Blood pressure, body mass index, fasting blood glucose, lipid profiles and CRP levels were measured and the LV mass indices were calculated using ECGs. Serum OPG levels were measured by ELISA. The presence of calcification in the aortic notch was checked by a chest X-ray. The subjects were divided into four groups according to the number of stenotic vessels. The mean serum OPG levels increased significantly as the number of stenotic vessels increased, and the mean serum OPG levels were higher in the group with three-vessel disease compared with the groups with no- or one-vessel disease. The mean serum CRP level was significantly higher in the group with three-vessel disease compared with the groups with no-, one- and two-vessel disease. Age and LV mass index showed significant positive correlations with serum OPG levels, although significance was lost after an adjustment for age. Serum CRP levels were positively correlated with serum OPG levels even after an adjustment for age. There were no differences in serum OPG levels according to the presence of fasting hyperglycaemia or aortic calcification. In conclusion, serum OPG level was related to the severity of stenotic coronary arteries and serum CRP levels. LV mass indices showed no significant correlation with OPG levels. The precise mechanism for the role of OPG in atherosclerosis needs to be investigated further.

In normoglycemic Koreans, insulin resistance and adipocity are independently correlated with high blood pressure.

BACKGROUND: There is some controversy about the role of insulin resistance (IR) in the regulation of blood pressure (BP). Moreover, a large study of the association between BP and IR has not been conducted in normal glucose tolerance Asians. The present study investigated the relationships between IR, body mass index (BMI) and waist circumference and BP in normoglycemic Koreans. METHODS AND RESULTS: Anthropometric indices of adiposity, metabolic variables (fasting serum insulin and a homeostasis model assessment (HOMA) index of insulin sensitivity), BP and several cardiovascular risk factors were measured during a cross-sectional survey of 49,076 normoglycemic Korean subjects. A high BP was defined as a systolic BP >/=140 mmHg or a diastolic BP >/=90 mmHg. The prevalence of high BP by HOMA grading was 0.985 (95% confidence interval (CI) 0.857-1.132, p=0.835), 1.180 (95% CI 1.032-1.350, p=0.016), 1.289 (95% CI 1.129-1.472, p<0.001), and 1.540 (95% CI 1.341-1.768, p<0.001) times higher in subjects in the second, third, fourth, and fifth quintiles, respectively, compared with those in the first quintile. In addition, age, sex, waist circumference and BMI were found to be significantly associated with a high BP. CONCLUSION: IR, BMI and waist circumference are independently correlated with high BP in normoglycemic Koreans.

Downregulation of p38 kinase pathway by cAMP response element-binding protein protects HL-60 cells from iron chelator-induced apoptosis.

The signaling mechanisms that control apoptotic events evoked by iron chelators are largely unknown. We found that cAMP response element-binding protein (CREB) is cleaved during iron chelator deferoxamine (DFO)-induced apoptosis, and that the cleavage is largely prevented by the cell-permeable analog of cAMP, dibutyryl-cAMP (dbcAMP), a known CREB activator. In addition, dbcAMP profoundly reduced DFO-induced apoptosis along with significant suppression of caspase-3 and -8 activation and inhibition of loss of mitochondrial potential. These results led us to investigate whether CREB activation is functionally connected with the MAPK family members because we previously demonstrated that p38 kinase is involved in iron chelator-induced apoptosis of HL-60 cells. dbcAMP by itself rapidly induced CREB phosphorylation but dramatically inhibited DFO-induced phosphorylation of all three MAPK family members. However, disruption of CREB expression by antisense oligodeoxyribonucleotide (AS-ODN) only restored p38 kinase activation, and simultaneously attenuated dbcAMP-induced protection of HL-60 cells from DFO-induced cell death. Conversely, inhibition of p38 kinase activity by SB203580 significantly reduced DFO-induced CREB cleavage as well as apoptosis, indicating a cross-talk between CREB and p38 kinase. Collectively, these results demonstrate that cAMP-dependent CREB activation plays an important role in protecting HL-60 cells from iron chelator-induced apoptosis, presumably through downregulation of p38 kinase.