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This study aimed to investigate the effects of different amoxicillin (AMX) dosing schedules on bismuth quadruple therapy in Helicobacter pylori treatment-naïve patients. A total of 139 H. pylori-infected patients received a 2-week eradication regimen consisting of 50 mg tegoprazan, 500 mg clarithromycin, and 300 mg bismuth tripotassium dicitrate twice daily, 1000 mg AMX twice daily (BID group), or 500 mg AMX four times daily (QID group). We performed a urea breath test to evaluate H. pylori eradication eight weeks after treatment and compared the H. pylori eradication rate, patient compliance, and adverse drug events between the BID and QID groups. Based on propensity score matching, 114 and 100 patients were included in intention-to-treat (ITT) and per-protocol (PP) analyses, respectively. The H. pylori eradication rate did not differ significantly according to the ITT (82.5% vs. 87.7%, p = 0.429) and PP (95.9% vs. 98.0%, p = 0.536) analyses between the BID and QID groups. No significant differences were found in treatment compliance or adverse drug event rates between the two groups. In conclusion, the eradication rate of first-line H. pylori therapy containing tegoprazan, clarithromycin, and bismuth was not affected by AMX dosing schedules administered twice and four times daily.

We theoretically evaluate the performance of spurious-tone suppression of a multi-loop optoelectronic oscillators (MOEO) based on closed-loop analysis. Spurious tones are unwanted oscillation signals due to the cavity effect of long-length optical fiber and the severe drawbacks of optoelectronic oscillator (OEO). The spurious tones can be suppressed using the MOEO configuration with two controllable loop parameters of length and power ratios between multiple loops. We propose the method of closed-loop analysis to accurately extract the loop parameters and to increase spurious-tone suppression ratio (SSR). We successfully evaluated the MOEO performances with various loop-power ratios and achieved an SSR of 86 dB with a phase noise of −115 dBc/Hz at 10 kHz offset for a triple-loop OEO configuration by extracting the optimum power ratio of 0.332:0.131:0.537.

Background/Aims The aim of this in vivo animal study was to evaluate the effectiveness and safety of dedicated cold snare (DCS) compared with those of traditional snare (TS) for cold snare polypectomy (CSP). Methods A total of 36 diminutive (5 mm) and 36 small (9 mm) pseudolesions were made by electrocoagulation in the colons of mini-pigs. Results For the diminutive lesions, there were no significant differences in technical success rate, procedure time, or complete resection rate between the DCS and TS groups; the rate of uneven resection margin in the DCS group was significantly lower than that of the TS group. For small lesions, technical success rate and complete resection rate were significantly higher in the DCS group than in the TS group (100% [18/18] vs. 55.6% [10/18], p=0.003; 94.4% [17/18] vs. 40% [4/10], p=0.006). In addition, the procedure duration was significantly shorter, and the rate of uneven resection margin was significantly lower in the DCS group (28.5 sec vs. 66.0 sec, p=0.006; 11.1% [2/18] vs. 100% [10/10], p

Background/Aims Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) can serve as biomarkers for diagnosing and assessing disease activity in ulcerative colitis (UC). We investigated their clinical significance in UC. Methods We analyzed 48 patients with UC who underwent measurement of fecal calprotectin (FC) and endoscopy and 96 age- and sex-matched healthy controls. NLR and PLR were compared between the patients and healthy controls. The endoscopic activity was divided into 2 groups: group 1 (mild to moderate inflammation) and group 2 (severe inflammation) according to the Mayo endoscopic subscore in UC. Results To diagnose UC, the optimal cutoff of NLR and PLR was 2.26 (sensitivity 54.2%; specificity 90.6%; positive likelihood ratio 5.778, 95% confidence interval [CI] 2.944–11.339; area under the curve [AUC] 0.774, 95% CI, 0.690–0.859) and 179.8 (sensitivity 35.4%; specificity 90.6%; positive likelihood ratio 3.778, 95% CI 1.821–7.838; AUC 0.654, 95% CI 0.556–0.753), respectively. The optimal cutoff to differentiate group 1 and group 2 was 3.44, 175.9, and 453 µg/g for NLR, PLR, and FC, respectively (sensitivity, 63.6% vs. 90.9% vs. 81.8%; specificity, 81.1% vs. 78.4% vs. 73.0%; positive likelihood ratio, 3.364 vs. 4.205 vs. 3.027; AUC, 0.714 vs. 0.897 vs. 0.813). PLR had the highest AUC and positive likelihood ratio. Conclusions NLR and PLR help differentiate patients with UC from healthy controls. NLR, PLR, and FC indicate endoscopic activity and may reflect intestinal mucosal conditions.

Background/Aims The eradication failure rate of standard triple therapy (proton pump inhibitor, clarithromycin, and amoxicillin) for Helicobacter pylori infection has increased owing to antibiotic resistance in Korea. We assessed whether Saccharomyces boulardii probiotic or broccoli sprout extract sulforaphane supplementation could increase the H. pylori eradication rate and/or reduce antibiotic-associated adverse events. Methods A total of 217 patients with H. pylori-positive chronic gastritis or peptic ulcer disease were recruited. Clarithromycin resistance was assessed in all patients by testing for A2142G and A2143G point mutations in H. pylori 23S rRNA using a dual-priming polymerase chain reaction (PCR) oligonucleotide. Thirty-four patients (17.3%) were clarithromycin-resistant and were excluded from the study. Finally, 183 patients with infections not resistant to clarithromycin were randomly assigned to triple therapy only (group A, n = 61), triple therapy plus probiotics (group B, n = 61), or triple therapy plus sulforaphane (group C, n = 61) groups. CYP2C19 polymorphisms were examined at position G681A of exon 5 and G636A of exon 4 by PCR with restriction fragment length polymorphism (PCR-RFLP) analysis. H. pylori eradication was assessed by 13C-urea breath test 4 weeks after treatment completion. Results The eradication rates were similar among the groups both in the intention-to-treat (A = 85.2%, B = 89.6%, and C = 81.6%) and per-protocol (A = 89.2%, B = 86.8%, and C = 96.3%) analyses. The frequencies of overall adverse events in the groups also did not differ (A vs. B: p = 0.574; A vs. C: p = 1.000). Conclusions Probiotic or sulforaphane with triple therapy for H. pylori infection neither increased the eradication rate nor reduced the occurrence of adverse events.

Background/Aims The eradication rate of the first-line triple therapy (a proton pump inhibitor, clarithromycin, and amoxicillin) for Helicobacter pylori infection has gradually decreased in Korea. We evaluated whether clinical parameters, clarithromycin resistance, and CYP2C19 genotype can affect the eradication failure. Methods A total of 203 patients with H. pylori-positive chronic gastritis were consecutively enrolled. They received clarithromycin-based triple therapy for 7 days. A clarithromycin resistance test was performed by detection of A2142G and A2143G point mutations in H. pylori 23S rRNA. The CYP2C19 genotype was examined for polymorphism G681A of exon 5 and G636A of exon 4 by polymerase chain reaction with restriction fragment length polymorphism. Eradication was assessed by a 13C-urea breath test 4 weeks after treatment. Results Of 203 patients, 190 completed the study. The eradication rate was 64.0% according to intention-to-treat analysis and 68.4% by per-protocol analysis. CYP2C19 genotypes were identified as follows: 75 poor metabolizers, 75 intermediate metabolizers, and 40 rapid metabolizers. Nonetheless, this polymorphism was not significantly associated with eradication failure (p = 0.682). Clarithromycin resistance was detected in 33/190 patients (17.4%), and their eradication rate was zero. Clarithromycin resistance (odds ratio [OR], 19.13; 95% confidence interval [CI], 9.35 to 35.09) and female gender (OR, 1.73; 95% CI, 1.15 to 4.25) were significantly associated with eradication failure. The other clinical parameters such as age, cigarette smoking, alcohol intake, the body mass index, hypertension, and diabetes were not significantly associated with eradication. Conclusions Clarithromycin resistance and female gender are factors affecting H. pylori eradication failure in patients with chronic gastritis.

In this study, the oscillation signal stabilization and spurious tone suppression of a directly modulated optoelectronic oscillator (DM-OEO) are simultaneously achieved by modulating a laser with a low-frequency radio frequency (RF) signal. The laser in the DM-OEO is modulated by a rectangular wave with a period inversely proportional to the frequency interval of the spurious tones and a duty cycle of 50%. The optical sidebands of the rectangular wave-modulated laser pulled the optical gain of the spurious tones of the DM-OEO, resulting in a spurious tone suppression and time stabilization in the DM-OEO signal. We achieve a 15 GHz DM-OEO with a 40.14 dB side-mode suppression ratio (SMSR) and 2.55 dB improvement in the oscillation power stability compared to that without RF modulation.

Recently, an alkaline earth hydride CaH _6 having a sodalitelike clathrate structure has been experimentally synthesized at megabar pressures with a maximum T _c of 215 K, comparable to that of a rare earth hydride LaH _10 . Here, based on first-principles calculations, we find that CaH _6 exhibits a huge peak in the Eliashberg spectral function α ^2 F around the low-frequency region of H-derived phonon modes, in contrast to LaH _10 having a widely spreading spectrum of α ^2 F over the whole frequencies of H-derived phonon modes. It is revealed that the huge peak of α ^2 F in CaH _6 is associated with an effective electron–phonon coupling (EPC) between low-frequency optical phonons and hybridized H 1 s and Ca 3 d states near the Fermi energy. As pressure increases, the strengthened H–H covalent bonding not only induces a hardening of optical phonon modes but also reduces the electron–phonon matrix elements related to the low-frequency optical modes, thereby leading to a lowering of the EPC constant. It is thus demonstrated that H-derived low-frequency phonon modes play an important role in the pressure-induced variation of T _c in CaH _6 . Furthermore, unlike the presence of two distinct superconducting gaps in LaH _10 , CaH _6 is found to exhibit a single isotropic superconducting gap.

Background/Aims Currently, a new over-the-scope clip (OTSC) system has been introduced. This system has been used for gastrointestinal perforations and fistulas in other countries. The aim of our study is to examine the therapeutic success rate of endoscopic treatment using the OTSC system in Korea. Methods This was a multicenter prospective study. A total of seven endoscopists at seven centers performed this procedure. Results A total of 19 patients were included, with gastrointestinal leakages from anastomosis sites, fistulas, or esophageal perforations due to Boerhaave’s syndrome. Among these, there were three gastrojejunostomy sites, three esophagojejunostomy sites, four esophagogastrostomy sites, one esophagocolonostomy site, one jejuno-jejunal site, two endoscopic full thickness resection site closures, one Boerhaave’s syndrome, two esophago-bronchial fistulas, one gastrocolonic fistula, and one colonopseudocyst fistula. The size of the leakage ranged from 5 to 30 mm. The median procedure time was 16 min. All cases were technically successful. Complete closure of the leak was achieved in 14 of 19 patients using OTSC alone. Conclusions The OTSC system is a safe and effective method for the management of gastrointestinal leakage, especially in cases of anastomotic leakage after surgery.

The high security of optical phased array (OPA) signals is an important requirement for OPA-based optical wireless communication (OWC). We propose a method for improving the security of OPA-based OWC systems using optically injection-locked (OIL) semiconductor lasers. We theoretically demonstrate the amplitude and phase modulation of OIL-OPA elements by controlling the injection-locking parameters of the OIL lasers. When a Taylor window function is applied as the amplitude profile of the OPA transmitter, the sidelobe level decreases by 22 dB and the unsecured distance reduces 10 times compared to the case without the Taylor window function. In addition, the unsecured area factor becomes 0.8%.

Background/Aims: Although the role of capsule endoscopy (CE) in Crohn's disease (CD) has expanded, CE is not used routinely for diagnosing and evaluating CD in Korea. We aimed to investigate current patterns of practice and evaluate the clinical significance of the use of CE in CD in Korean patients.Methods: Among 651 CE procedures performed for various indications, we retrospectively analyzed the medical records of patients who underwent CE in 57 cases of suspected CD (sCD) and 14 cases of established CD (eCD).Results: In the sCD group, CE was most commonly used for the initial diagnosis of CD (54.4%). Capsule retention was found in only 1 patient in the eCD group (1/71, 1.4%). In the sCD group, 28.1% of patients were diagnosed with CD on the basis of CE findings; other diseases diagnosed included tuberculous enteritis (7.0%), non-steroidal anti-inflammatory drug-induced enteropathy (5.3%), and other enteritis (17.5%). Only 11.5% of patients with eCD (14/122) underwent CE. The indication for CE in the 14 patients with eCD was to assess disease extent and activity. The overall diagnostic yield of CE was 59.7%. Therapeutic strategies were changed in 70.2% of patients in the sCD group and 50% of those in the eCD group based on CE findings.Conclusions: In clinical practice, CE was most commonly indicated for the initial diagnosis of CD and was not generally performed in patients with eCD. CE appears to be an effective diagnostic modality for evaluating sCD and is useful for determining therapeutic strategies for patients with sCD and those with eCD.

Background/AimsWe evaluated whether manometric subtype is associated with treatment outcome in patients with achalasia treated by peroral endoscopic myotomy (POEM).Methods : High-resolution manometry data and Eckardt scores were collected from 83 cases at two tertiary referral centers where POEM is performed. Manometric tracings were classified according to the three Chicago subtypes.Results : Among the 83 cases, 48 type I, 24 type II, and 11 type III achalasia cases were identified. No difference was found in pre-POEM Eckardt score, basal lower esophageal sphincter (LES) pressure, or integrated relaxation pressure (IRP) among the type I, type II, and type III groups. All three patient groups showed a significant improvement in post-POEM Eckardt score (6.1±2.1 to 1.5±1.5, p=0.001; 6.8±2.2 to 1.2±0.9, p=0.001; 6.6±2.0 to 1.6±1.4, p=0.011), LES pressure (26.1±13.8 to 15.4±6.8, p=0.018; 32.3±19.0 to 19.2±10.4, p=0.003; 36.8±19.2 to 17.5±9.7, p=0.041), and 4s IRP (21.5±11.7 to 12.0±8.7, p=0.007; 24.5±14.8 to 12.0±7.6, p=0.002; 24.0±15.7 to 11.8±7.1, p=0.019) at a median follow-up of 16 months.Conclusion : sPOEM resulted in a good clinical outcome for all manometric subtypes.

The performance of optical M-level (multi-level) amplitude shift keying (ASK) modulation is improved by directly using modulated optically injection-locked (OIL) semiconductor lasers. The direct modulation performance of free-running and OIL semiconductor lasers is evaluated and compared theoretically based on coupled-rate equation. We have found that OIL semiconductor lasers can significantly improve the modulation performance in terms of the signal eye opening and Q-factor. Additionally, we found that the Q-factor increases even more in the negative frequency detuning range due to its dependence on the locking parameters.

The side-lobe level (SLL) in optical phased array (OPA) systems should be reduced to ensure their high performance. We investigate theoretically the performance of an OPA based on optically injection-locked (OIL) semiconductor lasers. The phase and amplitude of the OIL laser are modulated by controlling the injection-locking parameters to reduce the SLL as well as to achieve beam steering. We successfully achieved an SLL reduction of >16 dB when compared with the uniform amplitude profile based on the application of the Taylor window function profile to the injection-locked OPA elements. The reduced SLL and high power efficiency achieved in this study can expedite the use of OPA in real field applications, such as free-space communication, imaging, and light detection and ranging (LIDAR).

To improve the detection rate of gastrointestinal tumors, image-enhanced endoscopy has been widely used during screening and surveillance endoscopy in Korea. In addition to narrow band imaging (NBI) with/without magnification, various types of electronic chromoendoscopies have been used, including autofluorescence imaging, I-scan, and flexible spectral imaging color enhancement. These technologies enable the accurate characterization of tumors because they enable visualization of microvascular and microsurface patterns. The present review focuses on understanding the principle and clinical applications of advanced imaging technologies other than NBI.

Background/AimsProviders may be hesitant to perform double-balloon enteroscopy (DBE) in the elderly because the increased number of co-morbidities in this population poses a greater risk of complications resulting from sedation. There are limited data on the use of DBE in the elderly. Here, we assessed the safety and efficacy of DBE in the elderly compared to those in younger patients.MethodsWe retrospectively analyzed the medical records of 158 patients who underwent 218 DBEs. Patients were divided into an elderly group (age ≥65 years; mean 71.4±5.4; n=34; 41 DBEs) and a younger group (age

We theoretically evaluate the performance of spurious-tone suppression of a multi-loop optoelectronic oscillators (MOEO) based on closed-loop analysis. Spurious tones are unwanted oscillation signals due to the cavity effect of long-length optical fiber and the severe drawbacks of optoelectronic oscillator (OEO). The spurious tones can be suppressed using the MOEO configuration with two controllable loop parameters of length and power ratios between multiple loops. We propose the method of closed-loop analysis to accurately extract the loop parameters and to increase spurious-tone suppression ratio (SSR). We successfully evaluated the MOEO performances with various loop-power ratios and achieved an SSR of 86 dB with a phase noise of -115 dBc/Hz at 10 kHz offset for a triple-loop OEO configuration by extracting the optimum power ratio of 0.332:0.131:0.537. [ABSTRACT FROM AUTHOR]

The dissociative adsorption of an H2 molecule on the Si(001) surface, which has been experimentally identified in terms of dissociation on one side of two adjacent Si dimers, is investigated by spin polarized density-functional calculations within the generalized-gradient approximation. In contrast to the prevailing nonmagnetic configuration of charge ordering, we propose a new ground state where the two single dangling bonds (DBs) created by H2 dissociation are antiferromagnetically coupled with each other. Such a spin ordering is found to be energetically favored over the previously proposed charge ordering. In the latter configuration, the buckling of the two DBs amounts to a height difference (Δh) of 0.63 Å, caused by a Jahn–Teller-like distortion, while in the former configuration, their buckling is almost suppressed to be Δh=0.03 Å as a consequence of spin polarization. [ABSTRACT FROM AUTHOR]

Using first-principles density-functional calculations, we investigate the reaction of acetone on the Si(001) surface, which exhibits the conversion from a kinetically controlled reaction to thermodynamically controlled one by means of thermal anneal or the highly confined electron beam of the scanning tunneling microscopy (STM) tip. We identified the four different reaction pathways forming not only two kinds of di-σ structures on top of a single Si dimer (termed as the [2+2] cycloaddition structure) and across the ends of two adjacent Si dimers but also two bridge-bonded dissociative structures (termed the “end-bridge” and “dimer-bridge” structures) involving two adjacent Si dimers. Our calculated energy profiles for the reaction pathways show not only that formation of the [2+2] cycloaddition structure is kinetically favored because of its low-energy barrier, but also that, as temperature increases, the kinetically favored [2+2] cycloaddition structure is converted to the more thermodynamically stable end-bridge and dimer-bridge structures via an intermediate state where the O atom forms a dative bond to the down Si atom of the buckled dimer. In addition, we find that the Si–C bonding (antibonding) states of the [2+2] cycloaddition structure appear at about 1–2 (2–3) eV below (above) the Fermi level, in which injected holes (electrons) through the STM tip can be created (trapped) to give rise to a Si–C bond breakage. These results manifest that the kinetically controlled reaction of acetone on Si(001) is associated with the [2+2] cycloaddition structure, rather than the α-H cleavage structure proposed by a recent STM experiment. [ABSTRACT FROM AUTHOR]

Two recent experiments for adsorbed acrylonitrile on the Si(001) surface reported different adsorption structures at 110 and 300 K. We investigate the reaction of acrylonitrile on Si(001) by first-principles density-functional calculations. We find that the so-called [4+2] structure in which acrylonitrile resides between two dimer rows is not only thermodynamically favored over other structural models but also easily formed via a precursor where the N atom of acrylonitrile is attached to the down atom of the Si dimer. The additional initial-state theory calculation for the C 1s core levels of adsorbed acrylonitrile provides an interpretation for the observed low- and room-temperature adsorption configurations in terms of the precursor and [4+2] structures, respectively. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The adsorption and reaction of acetonitrile (CH[sub 3]CN) on the Si(001) surface are investigated by first-principles density-functional calculations within the generalized gradient approximation. We find that two di-σ configurations in which CH[sub 3]CN bonds on top of a Si dimer and across the ends of two adjacent Si dimers in the same dimer row have adsorption energies of 1.43 and 1.35 eV, respectively. On the other hand, our calculated adsorption energy for the cross-row bridging structure (in which CH[sub 3]CN adsorbs between two dimer rows) is 0.52 eV, much smaller than that (0.91 eV) of a precursor state where the N atom bonds to the down-buckled atom of the Si dimer. This result does not support the conclusion drawn from a combination of temperature programmed desorption spectroscopy and density functional cluster calculations, where one of the two observed desorption states was assigned to the cross-row bridging structure. Based on our results for the energetics of various adsorption configurations and the energy profile of the reaction pathways, we provide a reinterpretation for the observed desorption states. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A combination of ultraviolet-visible absorption spectroscopy and first-principles density-functional calculations is used to investigate the optical-response properties of nitrogen(N)-doped titanium dioxide (Ti[O.sub.2]) films. The reproducible and controllable photoabsorption behavior of the N-doped Ti[O.sub.2] films is obtained by controlling the ion dose under certain conditions.

First-principles density-functional calculations are used to investigate two competing pathways for the dissociation of water and ammonia on a Si(001) surface. Results show that the two dissociation pathways occur through the Lewis acid-base reaction between the partially positive H ion and the electron-abundant up atom of the buckled Si dimer.

An introduction of a self-assembled borine wire on Si(001), which undergoes Peierls instability, giving rise to a periodic structural distortion, a band-gap opening, and the formation of a charge-density wave (CDW) are presented. The density-functional theory calculations showed that this molecular wire is stabilized by formation of a one-dimensional-CDW, accompanying a structural distortion with a double periodicity and a band-gap opening at the Fermi level.

Sedation, defined as the depressed level of consciousness, induced by drug administration, is widely used for gastrointestinal endoscopy to relieve a patient's anxiety and discomfort. In addition, successful procedure is anticipated with control of unintended movements. Endoscopic sedation, however, cannot be free from the risk of serious adverse events, e.g., cardiopulmonary compromise. Therefore, principles on personnel, facility and equipment, as well as performance itself, should be followed to prevent unfavorable incidents. In this article, sedation guidelines for the Accreditation of Qualified Endoscopy Units, issued by the Korean Society of Gastrointestinal Endoscopy, are presented [ABSTRACT FROM AUTHOR]

The synthesis of calix[4]hydroquinone nanotube arrays self-assembled with infinitely long one-dimensional (1-D) short hydrogen bonds and aromatic-aromatic interactions is presented. The competition between H-bonding and displaced pi-pi stacking in the assembling process is described.

This study examined how change the range of motion(ROM) of the neck and muscle tone of upper trapezius(UT) and Sternocleidomastoid(SCM) through the extracorporeal shock wave therapy(ESWT) and stretching exercise applied to subjects. Total 30 subjects who had forward head posture(FHP) in twenties healthy male and female each fifteen were applied with active stretching exercises (SE group) and additionally the extracorporeal shock wave therapy to 15 subjects for 7 weeks, total 14 times, twice a week (ESWT group). Before and after applying these experiments, in order to confirm the muscle tone of upper trapezius, sternocleidoma stoid, and the neck ROM of the subjects with FHP were measured by a goniometer. It was noticeable that in the tone of upper trapezius, the angle of neck extension and left bending, there were significant differences statistically in both groups. In addition, in the measurements of right bending of these group, there was a significant difference compared to between pre-intervention and post-intervention. On the other hand, there were no significant differences from sternocleidomastoid and neck flexion compared to between pre and post intervention in those two groups. E ven though there were no significant figures from the muscle tone of SCM and the angle of neck flexion, there were the other significant differences values. Moreover, it was ascertainable that without the extracorporeal shock wave therapy, the only conducting the stretching exercise to the subjects would work on the tone of upper trapezius, left and right neck bending and extension. Applying the stretching exercise could work on upper trapezius and the angle of neck extension and side bendings in the people who have forward head posture. [ABSTRACT FROM AUTHOR]

A self-assembly technique for fabrication of the heterogeneous pyridine-borine wire on the dangling-bond (DB) wire generated in a H-passivated Si(001) surface is proposed. The predictions will stimulate experimental works for fabrication of various heterogeneous molecular wires coupled with the DB wire on the Si(001) surface.

A theoretical analysis was conducted on the characteristics and performance of an optically combined dual-loop optoelectronic oscillator (OC-DOEO) based on an open-loop response method. The OC-DOEO utilizes the Vernier effect to eliminate spurious tones while accompanying the optical interference among the dual-loop signals. It was determined that the optical interference in the OC-DOEO significantly affected the OEO performances, including loop efficiency, phase noise, and spurious tones. It was demonstrated that DOEO performances can be maximized by controlling dual-loop parameters, such as the phase delay and power-split ratio, without spurious tones. [ABSTRACT FROM AUTHOR]

The phase modulation (PM) and amplitude modulation (AM) of optical signals can be achieved using a direct-modulated (DM) optical injection-locked (OIL) semiconductor laser. We propose and theoretically analyze a simple method to extract the phase component of a PM signal produced by a DM-OIL semiconductor laser. The pure AM component of the combined PM–AM signal can be isolated by square-law detection in a photodetector and can then be used to compensate for the PM–AM signal based on an optical homodyne method. Using the AM compensation technique, we successfully developed a simple and cost-effective phase extraction method applicable to the PM–AM optical signal of a DM-OIL semiconductor laser. [ABSTRACT FROM AUTHOR]

Background/Aims: Pneumoperitoneum is recognized as a benign and self-limiting finding after the insertion of a percutaneous endoscopic gastrostomy (PEG) tube, while complicated pneumoperitoneum is rarely reported. The aim of this study was to reappraise pneumoperitoneum following PEG. Methods: We retrospectively reviewed 193 patients who underwent PEG from May 2008 to May 2014. All patients had a follow-up upright chest or simple abdominal radiograph after PEG. Pneumoperitoneum was quantified by measuring the height of the air column under the diaphragm and graded as small (<2 cm), moderate (2−4 cm), or large (>4 cm). Clinically significant signs were defined as fever, abdominal tenderness or leukocytosis occurring after PEG insertion. Results: Of the 193 study patients, 9 (4.6%) had a pneumoperitoneum visualized by radiographic imaging, graded as small in 5 patients, moderate in 2 patients and large in 2 patients. Clinically significant signs were observed in 5 (55.5%) patients with fever reported in 4 patients, abdominal tenderness in 4 patients and leukocytosis in 4 patients. The time to resolution of free air was 2−18 days. Two patients (22.2%) with moderate or large pneumoperitoneum after PEG died from either pneumonia or septic shock. Conclusions: The clinical course of pneumoperitoneum after PEG is not always benign and self-limiting. These findings suggest that clinicians should not neglect a moderate or large pneumoperitoneum, particularly in patients who have an altered mental status or received antibiotics, since peritoneal irritation cannot be observed under these circumstances. [ABSTRACT FROM AUTHOR]

Background/Aims: Currently, the videofluoroscopic swallowing study (VFSS) is the standard tool for evaluating dysphagia. We evaluated whether the addition of endoscopist-directed flexible endoscopic evaluation of swallowing (FEES) to VFSS could improve the detection rates of penetration, aspiration, and pharyngeal residue, compared the diagnostic efficacy between VFSS and endoscopist-directed FEES and assessed the adverse events of the FEES. Methods: In single tertiary referral center, a retrospective analysis of prospectively collected data was conducted. Fifty consecutive patients suspected of oropharyngeal dysphagia were enrolled in this study between January 2012 and July 2012. Results: The agreement in the detection of penetration and aspiration between VFSS and FEES of viscous food (κ=0.34; 95% confidence interval [CI], 0.15 to 0.53) and liquid food (κ=0.22; 95% CI, 0.02 to 0.42) was “fair.” The agreement in the detection of pharyngeal residue between the two tests was “substantial” with viscous food (κ=0.63; 95% CI, 0.41 to 0.94) and “fair” with liquid food (κ=0.37; 95% CI, 0.10 to 0.63). Adding FEES to VFSS significantly increased the detection rates of penetration, aspiration, and pharyngeal residue. No severe adverse events were noted during FEES, except for two cases of epistaxis, which stopped spontaneously without requiring any packing. Conclusions: This study demonstrated that the addition of endoscopist-directed FEES to VFSS increased the detection rates of penetration, aspiration, and pharyngeal residue. [ABSTRACT FROM AUTHOR]

The search for one-dimensional electron systems with a giant Rashba-type spin splitting is of importance for the application of spin transport. Here we report, based on a first-principles density-functional-theory calculation, that Bi zigzag chains formed on a heterogeneous GaAs(110) surface have a giant spin splitting of surface states. This giant spin splitting is revealed to originate from spin-orbit coupling (SOC) and electric dipole interaction that are significantly enhanced by (i) the asymmetric surface charge distribution due to the strong SOC-induced hybridization of the Bi px, py, and pz orbitals and (ii) the large out-of-plane and in-plane potential gradients generated by two geometrically and electronically inequivalent Bi atoms bonding to Ga and As atoms. The results demonstrate an important implication of the in-plane and out-of-plane asymmetry of the Bi/GaAs(110) interface system in producing the giant spin splitting with the in-plane and out-of-plane spin components. [ABSTRACT FROM AUTHOR]

In this study, functional composite-pigment was prepared by a dry impact-blending method, using the inorganic materials used for coating of titanium dioxide, GCC, clay, and talc. After considering the particle size of inorganic pigment, the selected core powder and fine powder were mixed at a suitable mixing ratio. When powder was electrified, their fine particles could adhere by static electricity on the larger ones termed 'core particles', and then form an ordered mixture. During the surface modification of pigments, the energy caused by fine powder adhering to core particles was measured, and utilized in examining the efficiency of the change of particle size surface modification. Afterward, these were susceptible to being composited by impact force, resulting from very high-speed air circulation. After putting these surface modified pigments in water, their static electricity properties were measured by particle charge detector and Zeta potential tester. From these results, it was revealed that the elemental powder properties of papermaking inorganic pigment could be improved. [ABSTRACT FROM AUTHOR]

Using a hybrid density-functional theory (DFT) calculation including spin-orbit coupling (SOC), we predict that the zigzag antiferromagnetic (AFM) ground state of the honeycomb layered compound Na2IrO3 opens the observed insulating gap through a long-range magnetic order. We show that the effect of SOC and the correction of self-interaction error inherent in previous local or semilocal DFT calculations play crucial roles in predicting the band gap formation in Na2IrO3. It is revealed that the itinerant AFM order with a strong suppression of the Ir magnetic moment is attributed to a considerable hybridization of the Ir 5d orbitals with the O 2p orbitals. Thus, our results suggest that the insulating phase of Na2IrO3 can be represented as a Slater insulator driven by itinerant magnetism. [ABSTRACT FROM AUTHOR]

Background and study aim: This study aimed to evaluate the feasibility of a novel laser system for endoscopic submucosal dissection (ESD) of gastric epithelial neoplasia. Patients and methods: A total of 10 patients underwent ESD by a single expert endoscopist. A thulium 2-μm wavelength laser system was used for ESD procedures. Instead of using endoscopy knives, a 550-μm flexible silica fiber was inserted through the working channel of the endoscope. Results: In all patients, ESD was completed using only the thulium laser, without the need for endoscopy knives. The median total procedure time was 49 minutes (range 35-203). In 8/10 patients (80 %), no active bleeding was observed during ESD. The final pathologic mapping revealed low-grade dysplasia (n=4), differentiated adenocarcinoma (n=5), and signet ring cell carcinoma (n=1). Curative resection was achieved in 9/10 patients (90 %). There were no significant complications, such as delayed bleeding or perforation. Conclusions: The thulium laser system was feasible in ESD of gastric epithelial neoplasia. [ABSTRACT FROM AUTHOR]

Recent experimental evidence that fluorinated graphene creates local magnetic moments around F adatoms has not been supported by semilocal density-functional theory (DFT) calculations where the adsorption of an F adatom induces no magnetic moment in graphene. Here, we show that such an incorrect prediction of the nonmagnetic ground state is due to the self-interaction error inherent in semilocal exchange-correlation functionals. The present hybrid DFT calculation for an F adatom on graphene predicts not only a spin-polarized ground state with a spin moment of ∼1 μB, but also a long-range spin polarization caused by the bipartite nature of the graphene lattice as well as the induced spin polarization of the graphene states. The results provide support for the experimental observations of local magnetic moments in fluorinated graphene. [ABSTRACT FROM AUTHOR]

The precise driving force of the phase transition in indium nanowires on Si(111) has been controversial whether it is driven by a Peierls instability or by a simple energy lowering due to a periodic lattice distortion. The present van der Waals (vdW) corrected hybrid density functional calculation predicts that the low-temperature 8 x 2 structure whose building blocks are indium hexagons is energetically favored over the room-temperature 4 x 1 structure. We show that the correction of self-interaction error and the inclusion of vdW interactions play crucial roles in describing the covalent bonding, band-gap opening, and energetics of hexagon structures. The results manifest that the formation of hexagons occurs by a simple energy lowering due to the lattice distortion, not by a charge density wave formation arising from Fermi surface nesting. [ABSTRACT FROM AUTHOR]

Background/Aims: In hospitalized patients with acute steroid-refractory UC, infliximab has been demonstrated to be one of the medical rescue therapies to avoid colectomy. We report the result of a retrospective observational study to find the efficacy and safety of infliximab as a rescue therapy in our hospital. Methods: Between January 2007 and January 2010, 9 hospitalized patients with steroid-refractory UC were selected to receive three infusions of infliximab (5 mg/kg), at weeks 0, 2, and 6. Efficacy of treatment was evaluated at 8 weeks after the first infliximab infusion and at the end of follow-up period. Adverse events related to infliximab rescue therapy were also collected. Results: Seven patients (77.8%) had completed 3 infusions of infliximab and achieved clinical response at 8 weeks after the first infliximab infusion. Clinical remission rate and the rate of mucosal healing at 8 weeks were 57.1% (4/7) and 71.4% (5/7), respectively. They were followed up for median time of 24.9 months (19.5-53.6 months). One patient underwent emergency colectomy at weeks 2, due to colon perforation, while another patient had discontinued infliximab treatment at weeks 4, because of Clostridium difficile-associated colitis. Finally, colectomy was avoided in 77.8% (7/9) of cases. There was no mortality. Conclusions: Rescue therapy with infliximab has sustained clinical benefit in 88.9% of our hospitalized patients with acute steroid-refractory UC. Future prospective and long-term follow-up trials with a large number of patients are needed to confirm the efficacy and safety of the treatment. [ABSTRACT FROM AUTHOR]

We present theoretical investigations of the self-assembled growth of one-dimensional (1D) molecular lines directed across the dimer rows on the H-terminated Si(001)-(2 × 1) surface. Based on density-functional theory calculations, a growth approach of the 1D acetylacetone line is proposed, which involves the radical chain reaction initiated at two dangling-bond sites on one side of two adjacent Si dimers. It is also enabled that, if an H-free Si dimer were employed as the initial reaction site, a 1D acetylacetone line can grow along the dimer row. Our findings represent a novel insight into the growth of 1D molecular lines not only across but also along the dimer rows on the H-terminated Si(001)-(2 × 1) surface. [ABSTRACT FROM AUTHOR]

Using first-principles density-functional calculations, we investigate the structure and growth mechanism of allyl mercaptan lines on the H-terminated Si(100)-2 × 1 surface. The earlier structural model (termed the linear structure), where the terminal C atom of the C=C bond initially reacts with a single Si dangling bond, has been competing with a new structural model (termed the branched structure) where the medial C atom of the C=C bond initially reacts with a single Si dangling bond. We find that formation of the branched structure is kinetically unfavored over that of the linear structure. Moreover, the simulated scanning tunneling microscopy (STM) image of the branched structure cannot reproduce the features observed in the STM experiment, such as the position and origin of the bright protrusion. Thus, the present results do not support the branched structure in many respects. [ABSTRACT FROM AUTHOR]

We report a case of a 70-year-old man harboring a wide-necked thrombosed giant aneurysm of the left middle cerebral artery (MCA) on the M1 segment. The patient presented with generalized tonic-clonic seizures. A computerized tomography scan showed a calcified aneurysmal wall with perianeurysmal swelling. The aneurysm was successfully embolized using closed-cell nitinol stent-assisted coiling (Leo, BALT Co., Montmorency, France). [ABSTRACT FROM AUTHOR]

A 59-year-old Asian woman suffered from a TCH followed by sudden, binocular blurred vision, mimicking pituitary apoplexy. The diagnostic workup (including fluorescein angiography, MRI of the brain, and CSF analysis) showed severe optic disc swelling and dye leakage of multiple faint hyperfluorescent spots at retinal pigment epithelium level, diffuse pachymeningeal hypertrophy, and monocytic pleocytosis, respectively. VKH disease should be considered in the differential diagnosis of patients presenting with a TCH followed by sudden, bilateral decreased visual acuity. [ABSTRACT FROM AUTHOR]

A recent scanning tunneling microscope nanolithography technique can fabricate one-dimensional “dangling-bond (DB) wire” by the selective removal of H atoms from a H-passivated Si(001) surface along the Si dimer row. We here theoretically investigate the bonding geometry, band structure, and binding mechanism of an armchair (3,3) single-walled carbon nanotube (CNT) adsorbed on the DB wire. We find that the formation of C–Si bonds between the CNT and the DB wire gives rise to hybridization between the carbon π-bond states and the Si dangling-bond states. This hybridization breaks the rotational symmetry of the (3,3) CNT whose π-bonding and π-antibonding bands cross at the Fermi level. As a result, the adsorbed CNT opens an energy gap of ∼0.1 eV, yielding a metal-to-semiconductor transition. [ABSTRACT FROM AUTHOR]

We present first-principles density-functional calculations for the electronic properties of nitrogen(N)-doped as well as carbon(C)-doped titanium dioxide (TiO2). We find that the bands originating from N (C) 2p states appear in the band gap of TiO2, but the mixing of N (C) with O 2p states is too weak to produce a significant band-gap narrowing. Our results are consistent with several recent experimental data of N-doped TiO2, where the absorption of visible light is due to isolated N 2p states above the valence-band maximum of TiO2 rather than due to a band-gap narrowing. [ABSTRACT FROM AUTHOR]