Search for Boosted Dark Matter in COSINE-100

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7  kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

Self-Assembled Nanostructures of Homo-Oligopeptide as a Potent Ice Growth Inhibitor

This study reports the formation of self-assembled nanostructures with homo-oligopeptides consisting of amino acids (i.e., alanine, threonine, valine, and tyrosine), the resulting morphologies (i.e., spherical shape, layered structure, and wire structure) in aqueous solution, and their potential as ice growth inhibitors. Among the homo-oligopeptides investigated, an alanine homo-oligopeptide (n = 5) with a spherical nanostructure showed the highest ice recrystallization inhibition (IRI) activity without showing a burst ice growth property and with low ice nucleation activity. The presence of nanoscale self-assembled structures in the solution showed superior IRI activity compared to an amino acid monomer because of the higher binding affinity of structures on the growing ice crystal plane. Simulation results revealed that the presence of nanostructures induced a significant inhibition of ice growth and increased lifetime of hydrogen bonding compared with unassembled homo-oligopeptide. These results envision extraordinary performance for self-assembled nanostructures as a desirable and potent ice growth inhibitor.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

Detection efficiency calibration for an array of fourteen HPGe detectors

The CUP array of germanium (CAGe) is an array of fourteen high-purity germanium (HPGe) detectors. The detection efficiency of full-energy-peak emitted from the various samples assayed on the CAGe was calculated using the Monte Carlo simulation toolkit GEANT4. If the dead layer on the surface of the crystal is treated in the simulation as a continuous part of the active crystal, then the detection efficiency will be overestimated. Thus, the detection efficiency of the CAGe was adjusted using multi-nuclide source data and Monte Carlo simulations. The gamma spectra of the known activity source were obtained for each HPGe detector of the CAGe. The detection efficiency measured by the multi-source data was smaller than that of simulation data if the simulation treated the whole volume of germanium crystals as active for gamma detection. By optimizing the dead layers' thicknesses in the simulation, the detection efficiency calculated by the simulation could be matched to that of multi-source data.

Precise control over the silica shell thickness and finding the optimal thickness for the peak heat diffusion property of AuNR@SiO2

Silica-coated gold nanorods (AuNRs) exhibit significantly enhanced photothermal effects and photoacoustic (PA) signal intensities, which is beneficial for various nanophotonic applications in materials science. However, the silica shell thickness for optimum enhancement is not fully understood and is even controversial depending on the physical state of the silica shell. This is because of the lack of systematic investigations of the nanoscale silica shell thickness and the photothermal effect. This study provides a robust synthetic method to control the silica shell thickness at the nanoscale and the physical state-dependent heat diffusion property. The selected base and solvent system enabled the production of silica-coated AuNRs (AuNR@SiO₂) with silica shell thicknesses of 5, 10, 15, 20, 25, 30, 35, and 40 nm. AuNRs with a 20 nm silica shell showed the highest photothermal effect with a 1.45-times higher photothermal efficiency than that of AuNRs without a silica shell. The low density of the silica shell on the AuNRs showed a low photothermal effect and photostability. It was found that the disruption of cetyltrimethyl ammonium bromide (CTAB) layers on the AuNRs was responsible for the low photostability of the AuNRs. The simulation study for the heat diffusion property showed facilitated heat diffusion in the presence of a 20 nm silica shell. In a cell-based study, AuNRs with a 20 nm silica shell showed the most sensitive photothermal effect for cell death. The results of this robust study can provide conclusive conditions for the optimal silica shell thickness to obtain the highest photothermal effect, which will be useful for the future design of nanomaterials in various fields of application.

Real-time surface-enhanced Raman scattering-based live cell monitoring of the changes in mitochondrial membrane potential

Obtaining molecular information on cells in real time has been a critical challenge in studying the interaction between molecules of interest and intracellular components. Fluorescence-based methods have long served as excellent tools to study such important interactions. In this paper, we introduce a Raman scattering-based method as a promising platform to achieve the real-time monitoring of subtle molecular changes occurring within cells. We found that the Raman scattering-based method enabled monitoring changes in the mitochondrial membrane potential at the single-cell level in rheumatoid arthritis synovial fibroblasts induced by tumor necrosis factor-alpha (TNF-α) protein, various chemicals (MgCl₂, FCCP, and sodium pyruvate), and a non-chemical stimulus (i.e., light). The triphenylphosphine-modified gold nanoparticles were selectively localized in the mitochondria and showed the characteristic Raman spectrum of cytochrome C and other Raman spectra of molecular components inside the cell. The surface-enhanced Raman spectrum originating from mitochondria was sensitively changed over time when mitochondrial depolarization was induced by the addition of TNF-α, or chemicals known to induce mitochondrial depolarization. The Raman-based signal changes were well matched with results of the conventional fluorescence-based analysis. However, in contrast to the conventional approach, the Raman-based method enables monitoring such changes in real time and provides detailed molecular information in terms of the interaction of molecules. Therefore, these results highlight the possibility of surface-enhanced Raman scattering-based live cell analysis for future proteomics or drug-screening applications.

Solution-Based One-Step Preparation of Three-Dimensional Self-Assembled Octadecyl Silica Nanosquare Plate and Microlamella Structures for Superhydrophobic and Icephobic Surfaces

Icephobic surfaces have gained immense attention owing to their significant roles in decreasing the energy consumption of refrigerators and in improving safety issues by preventing the formation of ice on them. Superhydrophobic surfaces incorporating micro- or nanoscale roughness and hydrophobic functional groups have been shown to prevent ice accumulation. Herein, we report a simple, low-cost, and solution-based one-step process for the production of superhydrophobic surfaces with three-dimensional (3D) self-assembled structures. The controlled hydrolysis and polycondensation of n-octadecyltrichlorosilane (OTS-Cl) in an acetone solution produced a highly uniform superhydrophobic surface on various substrates such as glass, metals, and polymers without the limitation of the surface curvature structure. The as-prepared 3D self-assembled surface exhibited a very high contact angle of 161.7° and a low contact hysteresis of 1.47°. The solvent type, H₂O content in acetone, and carbon chain length of the silane compound were critical in the formation of self-assembled nanostructures. The thickness of the superhydrophobic 3D self-assembled structure could be varied by controlling the surface properties of the glass substrate. In addition, a novel octadecyl silica nanosquare plate structure was formed as an intermediate for the microlamella structure. The water drop impact experiments on the 3D self-assembled superhydrophobic glass substrates at low temperatures (T < -25 °C) showed that the as-prepared superhydrophobic glass possessed a high impalement threshold for water contact, resulting in excellent and stable icephobic properties. The preparation method proposed in this study is scalable and can be used on a flat glass surface or in a glass vial inside a glass tube. Moreover, it can be applied to various substrates such as metals and polyurethane surfaces with curvature. Therefore, the solution-based self-assembly method proposed in this study is a promising approach to produce superhydrophobic and icephobic surfaces on a wide range of substrates regardless of their structure and properties.

Hyperattenuating lesions after mechanical thrombectomy in acute ischaemic stroke: factors predicting symptomatic haemorrhage and clinical outcomes

AIM

To evaluate the clinical significance of hyperattenuating lesions on CT after mechanical thrombectomy for acute ischaemic stroke, and to identify imaging factors that predict symptomatic haemorrhage and unfavourable outcomes.

MATERIALS AND METHODS

Seventy-eight patients with acute ischaemic stroke in the anterior circulation who underwent mechanical thrombectomy were evaluated. All patients underwent post-interventional unenhanced computed tomography (CT) within 24 h and follow-up CT or magnetic resonance imaging (MRI) within 7 days. Baseline characteristics and clinical outcomes were compared between patients with and without hyperattenuating lesions. In patients with hyperattenuating lesions, clinical and imaging factors that predict symptomatic haemorrhage and unfavourable outcomes were determined.

RESULTS

Fifty-six of 78 patients (71.8%) demonstrated hyperattenuating lesions on post-interventional CT. Patients with hyperattenuating lesions showed lower Alberta Stroke Program Early CT score (ASPECTS), persistent/symptomatic haemorrhage, and unfavourable outcomes than those without. In patients with hyperattenuating lesions, larger hyperattenuating lesion volume (>21.3 ml; OR, 55.60, p<0.001) and perilesional oedema (OR, 46.04, p=0.015) were independent factors predicting symptomatic haemorrhage. Older age (OR, 1.2, p=0.006) and lower ASPECTS (OR, 0.45, p=0.046) were independent factors predicting unfavourable outcomes in patients with hyperattenuating lesions. Adding the volume of the hyperattenuating lesion to age and ASPECTS increased the predictive performance of unfavourable outcomes (area under the curve 0.874 versus 0.934, p=0.043).

CONCLUSIONS

Hyperattenuating lesions on post-interventional CT are associated with increased risk of symptomatic haemorrhage and unfavourable outcomes. Larger hyperattenuating lesion volume is an independent factor of symptomatic haemorrhage and it has added predictive value for unfavourable outcomes.

Morphologic and morphometric characteristics of the adductor minimus in Korean: its topographic relationship with respect to neighboring anatomical structure and clinical significance

BACKGROUND

The aim of this study was to clarify the morphologic and morphometric characteristics of the adductor minimus (AMi) and to observe its topographic relationships relative to the adjacent anatomical structures.

MATERIALS AND METHODS

This study investigated 54 thighs of 27 Korean cadavers.

RESULTS

The AMi was a small and flat muscle observed in 94.4% of the specimens. It originated from the inferior ramus of the pubis as the upper part of the adductor magnus (AMa), and inserted from the lesser trochanter to the upper part of the linea aspera. The AMi was completely separate from the AMa in 63.0% of the specimens. The medial circumflex femoral artery was always found at the superior border of the AMi, while the first and second perforating arteries were found inferior to the muscle in 55.6% and 37.0% of specimens, respectively. A supernumerary muscle (SM) was found with the AMi in 42.6% of the specimens, and it originated from the inferior ramus of the pubis and inserted into the posterior side of the lesser trochanter. The obturator externus and AMi were found superoposterior and inferior to the SM, respectively, while the posterior branch of the obturator nerve passed underneath it.

CONCLUSIONS

The results of this study may provide physicians with the accurate anatomical knowledge that they require for managing groin pain and applying a regional nerve block with ultrasound guidance in this adductor region.

Association between body mass index and stroke severity in acute ischaemic stroke with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

The objective of this study was to investigate the association between body mass index (BMI) and both initial stroke severity at presentation and functional outcomes after acute ischaemic stroke (AIS) in patients with non-valvular atrial fibrillation (NVAF).

METHODS

Patients were categorized on the basis of their BMI into underweight (BMI <18.5, n = 111), normal (18.5 ≤ BMI <25, n = 1036) and overweight to obese (BMI ≥25, n = 472) groups. Initial stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) score and functional outcomes were assessed using the modified Rankin Scale score at discharge. The differences in stroke severity and functional outcomes were compared between groups using robust log-linear regression with a Poisson distribution and binary logistic regression analysis.

RESULTS

A total of 1619 AIS patients with NVAF from six hospitals were included. Compared with the NIHSS scores [median 5, interquartile range (IQR) 2-14] of normal-weight patients, the NIHSS scores (median 9, IQR 4-19) of underweight patients were more likely to be higher, whereas those of overweight to obese patients were lower (median 4, IQR 1-12) (P < 0.001). In terms of functional outcomes after stroke, underweight patients had a higher risk of poor functional outcomes (odds ratio 1.78, 95% confidence interval 1.09-2.56, P = 0.01) but overweight to obese patients had no significant difference in functional outcomes compared with normal-weight patients.

CONCLUSION

An inverse association was found between BMI and stroke severity in AIS patients with NVAF. This suggests the presence of an obesity paradox for short-term outcomes in patients with NVAF.

P997Improving left atrial appendage occluder size determination by using 3-dimensional printing model of the left atrial appendage

Introduction

Given the complexity of left atrial appendage (LAA) structure, current 2D based LAA occluder (LAAO) size prediction system using transesophageal echocardiography (TEE) has limitations.

Objective

To assess the accuracy of LAAO size determination method by implantation simulation using a 3D printed model compared with a conventional method based on TEE.

Methods

We retrospectively reviewed 57 cases with percutaneous LAAO using Amplatzer Cardiac Plug and Amulet from 2014 to 2018. We excluded cases without cardiac CT (21 cases) or with peri-device leakage or inappropriate position of the device on six months follow up TEE (6 cases), or with paroxysmal atrial fibrillation (2 cases). We finally included 28 cases with anatomically and physiologically properly implanted LAAO, using the final size of the implanted devices as a standard for the size prediction accuracy. We generated 3D printing model from cardiac CT images. LAAO size was determined with device implantation simulation using 3D printing model and occluder devices (Figure C), and conventional 2D TEE measurements by two experienced cardiologists who were blinded to the size of the finally implanted device.

Results

The accuracy in size of 3D printed left atrium (LA) models, compared with CT image sources, were validated by measuring the distance between artifacts which were intentionally implanted to LA model during image processing. There was minimal bias (−0.11 mm) between 3D images and printed LA models (Figure A). As plotted in Figure B, LAAO sizing by implantation simulation with 3D printing model showed excellent agreement with actually implanted LAAO size (r=0.927; bias=0.7±2.5), while LAAO sizing by 2D TEE measurements remained poor (r=0.544; bias 2.3±6.7).

Conclusions

LAAO size determination by using 3D printing model of LAA showed excellent accuracy. A prospective study to evaluate the clinical utility of this method should be done in future.

Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment

We present new constraints on the dark matter-induced annual modulation signal using 1.7 years of COSINE-100 data with a total exposure of 97.7 kg yr. The COSINE-100 experiment, consisting of 106 kg of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7  cpd/kg/keV background rate on average in the 2-6 keV energy region of interest. Using a χ-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092±0.0067  cpd/kg/keV and 127.2±45.9  d, respectively.

Raman-Based in Situ Monitoring of Changes in Molecular Signatures during Mitochondrially Mediated Apoptosis

Obtaining molecular information from inside cells is an important topic to understand the outcome of molecular interactions between potential drug molecules and biomolecules inside cells. To envision this goal, we investigated the surface-enhanced Raman scattering-based single-cell spectroscopic method to monitor changes in intracellular molecular signatures during mitochondrially mediated apoptosis in real time. Triphenylphosphine-modified gold nanoparticles were localized successfully to the mitochondria and greatly enhanced to obtain the intrinsic Raman scattering spectrum of mitochondria and cytochrome c in the live cell. Photothermally induced apoptosis showed a moderate decrease in the disulfide bond and a sharp increase in β-sheet structures depending on the input-laser power, along with morphological changes. However, chemical drug induced-apoptosis showed more subtle changes in the disulfide bond, as well as changes in Raman peaks corresponding to cytochrome c, and the appearance of a new peak at 1420 cm-1, which enabled us to study the molecular interactions within the mitochondria in real time from a single cell, following treatment with a novel pyruvate dehydrogenase kinase inhibitor.

First Direct Search for Inelastic Boosted Dark Matter with COSINE-100

A search for inelastic boosted dark matter (IBDM) using the COSINE-100 detector with 59.5 days of data is presented. This relativistic dark matter is theorized to interact with the target material through inelastic scattering with electrons, creating a heavier state that subsequently produces standard model particles, such as an electron-positron pair. In this study, we search for this electron-positron pair in coincidence with the initially scattered electron as a signature for an IBDM interaction. No excess over the predicted background event rate is observed. Therefore, we present limits on IBDM interactions under various hypotheses, one of which allows us to explore an area of the dark photon parameter space that has not yet been covered by other experiments. This is the first experimental search for IBDM using a terrestrial detector.

Dielectric function, critical points, and Rydberg exciton series of WSe2 monolayer

The complex dielectric function ([Formula: see text]) of WSe₂ monolayer grown by atomic layer deposition is investigated using spectroscopic ellipsometry. Band structure parameters are obtained by standard line-shape analysis of the second-energy-derivative of [Formula: see text] spectra. The fundamental band gap is observed at 2.26 eV, corresponds to transition between valence band (VB) maximum at the K point and conduction band (CB) minimum at Q point in the Brillouin zone (BZ). Two strong so-called A and B excitonic peaks in [Formula: see text] spectra originate from vertical transitions from spin-orbit split (0.43 eV) VB to CB at K point of the BZ. Binding energies of A and B exactions are 0.71 and 0.28 eV, respectively. Well resolved five excited excitons states has been detected within the spectral region between A and B. Energy profile of the Rydberg series shows significant deviation from the hydrogenic behavior, discussed in connection with the 2D hydrogen model. Results presented here will improve our understanding about the optical response of 2D materials and will help to design better optoelectronic applications and validate theoretical considerations.

Patients and Their Caregivers' Burdens for Parkinson's Disease in Korea

Objective

Many patients with Parkinson’s disease (PD) suffer from motor and non-motor symptoms. According to these variable symptoms of PD, patients or caregivers have a poorer quality of life than patients with other neurodegenerative diseases. Since the difficulties are varied for all patients, prioritizing their difficulties differs among all cases. The goal of this study was to investigate the burdens of PD among the caregivers as well as patients and to identify areas requiring aid from the government.

Methods

We surveyed the awareness and perceptions of PD in patients and caregivers of PD by a face-to-face questionnaire. The questionnaire was divided into three sections: symptoms of PD (part A), desire for policies (part B), and difficulties faced by their caregivers (part C). Part A comprised 8 questions, Part B had 2 questions, and Part C had 3 questions.

Results

In total, 853 subjects (702 patients and 151 caregivers) were enrolled in this study. The major difficulties experienced by PD patients were physical (67%), psychiatric (60%) and socio-economic (52%). Assessing the physical difficulties, more than half the patients experienced severe difficulties (29% very severe, 39% severe). Psychiatric difficulties were assessed as severe (35%) and very severe (21%) among the patients. Severe difficulties were also experienced socio-economically, at 52% in patients and 49% in caregivers, especially among patients in their fifties (58%) and those with their spouse (65%) as caregivers. The topmost need was the introduction of new technology for treatment of PD (62%), followed by relief of costs for treatment (38%) and a family support system (31%). The majority (91%) of the patients were diagnosed with PD within two years after onset of symptoms.

Conclusion

We know that the difficulties of PD and the needs for government assistance are different between patients and caregivers. These results emphasize that perceiving the difficulties and needs of patients and caregivers early can help to prevent and ameliorate the burden of disease.

Catheter probe endoscopic ultrasonography by using cold lubricating jelly-filled method for esophageal subepithelial tumors

Catheter probe endoscopic ultrasonography (C-EUS) by ultrasonographic jelly-filled method has been used to evaluate esophageal subepithelial tumors (SETs). Ultrasonographic jelly is safe on the skin, but its internal safety has not been demonstrated. The jelly stored at room temperature is easily injected into the esophagus through the instrument channel of the endoscope. However, using jelly stored at room temperature remains problematic because the jelly is drained rapidly. We used cold lubricating jelly and an intravenous extension tube to resolve these problems. In this study, we evaluated the safety and efficacy of cold lubricating jelly-filled method. The medical records of patients who underwent C-EUS by using water or cold lubricating jelly-filled method for esophageal SETs from March 2013 to September 2016 in Gangneung Asan hospital were reviewed. Clinical characteristics and EUS findings were evaluated retrospectively. Image quality and procedure time between water and cold lubricating jelly-filled method were compared retrospectively. This study included 138 patients (74 males, 64 females) with esophageal SET with a mean age of 57.1 ± 11.1 years. Thirty-four patients had lesions in the upper esophagus, 58 patients had lesions in the middle esophagus, and 46 patients had lesions in the lower esophagus. The EUS diagnoses were leiomyoma (82.6%), hemangioma (4.3%), extrinsic compressive lesion (3.6%), granulosa cell tumor (2.9%), ectopic calcification (1.4%), cyst (1.4%), lipoma (0.7%), varix (0.7%), and inconclusive lesion (2.2%). The mean image score in the cold lubricating jelly filled-method group was higher than that in the water-filled method group (3.2 ± 0.7 vs. 2.8 ± 0.7, P = 0.002). The procedure time in the cold lubricating jelly filled-method group was shorter than that in the water-filled method group (10 minutes 27 seconds ± 4 minutes 22 seconds versus 13 minutes 20 seconds ± 6 minutes 20 seconds, P = 0.045). No procedure-related complication was observed. C-EUS using the cold lubricating jelly-filled method seems to provide better image quality and shorter procedure time compared with C-EUS using the water-filled method.

Development of a simple computerized torsion test to quantify subjective ocular torsion

PurposeThe double Maddox-rod test (DMRT) and Lancaster red-green test (LRGT) are the most widely used tests worldwide to assess subjective ocular torsion. However, these tests require equipment and the quantified results of ocular torsion are only provided in rough values. Here we developed a novel computerized torsion test (CTT) for individual assessment of subjective ocular torsion and validated the reliability and accuracy of the test compared with those of the DMRT and LRGT.MethodsA total of 30 patients with cyclovertical strabismus and 30 controls were recruited. The CTT was designed using Microsoft Office PowerPoint. Subjects wore red-green filter spectacles and viewed gradually tilted red and cyan lines on an LCD monitor and pressed the keyboard to go through the slides, until both lines seemed parallel. All subjects underwent the CTT, DMRT, and LRGT. Intraclass correlation coefficients and Bland-Altman plots were analyzed to assess the acceptability of the CTT compared with that of the DMRT.ResultsBoth the DMRT and CTT showed no significant test-retest differences in the strabismus and control groups. The DMRT and CTT results demonstrated an acceptable agreement. The reliability of the CTT was better than that of the DMRT. The LRGT showed low sensitivity for the detection of ocular torsion compared with the DMRT (40.0%) and CTT (39.1%).ConclusionOur results suggest that the assessment of subjective ocular torsion using the CTT based on PowerPoint software is simple, reproducible, and accurate and can be applied in clinical practice.

Sterile Neutrino Search at the NEOS Experiment

An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3+1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin^{2}2θ_{14} is limited up to less than 0.1 for Δm_{41}^{2} ranging from 0.2 to 2.3 eV^{2} with a 90% confidence level.

Differences in Depressive Patterns According to Disease Severityin Early-Onset Alzheimer's Disease

BACKGROUND & OBJECTIVE

Depression frequently combines with dementia, including early-onset Alzheimer's disease (EOAD). We investigated differences in prevalence and characteristics of depressive symptoms according to dementia severity in EOAD patients.

METHODS

The 15-item Korean version of the Geriatric Depression Scale (GDS-15) was administered to 412 EOAD patients. Factor analysis was used to assess GDS-15 factor structure. We subdivided participants into three groups by disease severity, then compared the frequencies and scores of individual GDS-15 items and performed logistic regression analysis to assess associations between depressive symptoms and EOAD stage.

RESULTS

Factor analysis yielded three factor categories: 1) "hopelessness and ominousness" (symptoms no. 6, 8, 12, 14, 15); 2) "unhappiness and dissatisfaction" (no. 1, 3, 5, 7, 11); and 3) "monotony and lack of energy" (no. 2, 4, 9, 10, 13). Factor 2 depressive symptoms (no. 1, 5, 11) were less common in moderate EOAD. The risk of Factor 1 symptoms: no. 12 (OR, 2.04; 95% CI, 1.19-3.50; p = 0.010) and 14 (OR, 1.84; 95% CI, 1.07-3.16; p = 0.028) was higher in mild than very mild EOAD. The risk of Factor 2 symptoms: no. 9 (OR, 2.69; 95% CI, 1.08-6.71; p = 0.033) and 13 (OR, 2.12; 95% CI, 1.02-4.40; p = 0.043) was higher in moderate than mild EOAD.

CONCLUSION

We confirmed that depressive symptoms differ according to EOAD severity. When assessing depressive symptoms related to dementia progression, we recommend focusing on "hopelessness and ominousness" in very mild EOAD and "unhappiness and dissatisfaction" in mild EOAD.

Weight Change Is a Characteristic Non-Motor Symptom in Drug-Naïve Parkinson's Disease Patients with Non-Tremor Dominant Subtype: A Nation-Wide Observational Study

Despite the clinical impact of non-motor symptoms (NMS) in Parkinson’s disease (PD), the characteristic NMS in relation to the motor subtypes of PD is not well elucidated. In this study, we enrolled drug-naïve PD patients and compared NMS between PD subtypes. We enrolled 136 drug-naïve, early PD patients and 50 normal controls. All the enrolled PD patients were divided into tremor dominant (TD) and non-tremor dominant (NTD) subtypes. The Non-Motor Symptom Scale and scales for each NMS were completed. We compared NMS and the relationship of NMS with quality of life between normal controls and PD patients, and between the PD subtypes. Comparing with normal controls, PD patients complained of more NMS, especially mood/cognitive symptoms, gastrointestinal symptoms, unexplained pain, weight change, and change in taste or smell. Between the PD subtypes, the NTD subtype showed higher total NMS scale score and sub-score about weight change. Weight change was the characteristic NMS related to NTD subtype even after controlled other variables with logistic regression analysis. Even from the early stage, PD patients suffer from various NMS regardless of dopaminergic medication. Among the various NMS, weight change is the characteristic NMS associated with NTD subtype in PD patients.

Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment

The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3}  eV^{2}.

The KMDS-NATION Study: Korean Movement Disorders Society Multicenter Assessment of Non-Motor Symptoms and Quality of Life in Parkinson's Disease NATION Study Group

Background and Purpose

Nonmotor symptoms (NMS) in Parkinson's disease (PD) have multisystem origins with heterogeneous manifestations that develop throughout the course of PD. NMS are increasingly recognized as having a significant impact on the health-related quality of life (HrQoL). We aimed to determine the NMS presentation according to PD status, and the associations of NMS with other clinical variables and the HrQoL of Korean PD patients.

Methods

We surveyed patients in 37 movement-disorders clinics throughout Korea. In total, 323 PD patients were recruited for assessment of disease severity and duration, NMS, HrQoL, and other clinical variables including demographics, cognition, sleep scale, fatigability, and symptoms.

Results

In total, 98.1% of enrolled PD subjects suffered from various kinds of NMS. The prevalence of NMS and scores in each NMS domain were significantly higher in the PD group, and the NMS worsened as the disease progressed. Among clinical variables, disease duration and depressive mood showed significant correlations with all NMS domains (p<0.001). NMS status impacted HrQoL in PD (rS=0.329, p<0.01), and the association patterns differed with the disease stage.

Conclusions

The results of our survey suggest that NMS in PD are not simply isolated symptoms of degenerative disease, but rather exert significant influences throughout the disease course. A novel clinical approach focused on NMS to develop tailored management strategies is warranted to improve the HrQoL in PD patients.

Search for bosonic superweakly interacting massive dark matter particles with the XMASS-I detector

Bosonic superweakly interacting massive particles (super-WIMPs) are a candidate for warm dark matter. With the absorption of such a boson by a xenon atom, these dark matter candidates would deposit an energy equivalent to their rest mass in the detector. This is the first direct detection experiment exploring the vector super-WIMPs in the mass range between 40 and 120 keV. With the use of 165.9 day of data, no significant excess above background was observed in the fiducial mass of 41 kg. The present limit for the vector super-WIMPs excludes the possibility that such particles constitute all of dark matter. The absence of a signal also provides the most stringent direct constraint on the coupling constant of pseudoscalar super-WIMPs to electrons. The unprecedented sensitivity was achieved exploiting the low background at a level 10(-4)  kg-1 keVee-1 day-1 in the detector.

Differential impact of unrecognised brain infarction on stroke outcome in non-valvular atrial fibrillation

There has been little information regarding the impact of unrecognised brain infarctions (UBIs) on stroke outcome in patients with non-valvular atrial fibrillation (NVAF). By using volumetric analysis of ischaemic lesions, we evaluated the potential impact of UBIs on clinical outcome according to their presence and categorised type. This study enrolled 631 patients with NVAF having no clinical stroke history. UBIs were categorised into three types as territorial, lacunar, or subcortical. We collected stroke severity, functional outcome at three months, and the total volume of UBIs and acute infarction lesions. We investigated the association between clinical outcome and the type or volume of UBI, using a linear mixed model and logistic regression analysis. UBIs were detected in 285 (45.2 %) patients; territorial UBIs were observed in 24.4 % of patients (154/631), lacunar UBIs in 25 % (158/631), and subcortical UBIs in 15.7 % (99/631). Although initial stroke severity was not different between patients with UBIs and those without, those with UBIs had less improvement during hospitalisation, leading to poorer outcome at three months. Among the three types of UBIs, only territorial UBIs were associated with poor outcome, especially in patients with relatively smaller acute infarction volume. UBIs, in particular, territorial UBIs, may be considered as predictors for poor outcome after ischaemic stroke in patients with NVAF. Our results suggest that the impact of UBIs on clinical outcome differs according to the type of UBIs and the acute stroke severity.

Comparison of stent retriever and intra-arterial fibrinolysis in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

Although the stent retriever (SR) has shown a better reperfusion rate and clinical outcome than the older generation mechanical clot retrieval device, it is uncertain whether the SR is superior to intra-arterial fibrinolysis (IAF).

METHODS

Ischaemic stroke patients who were treated with SR or IAF as initial endovascular treatment modality for unilateral arterial occlusion in the anterior circulation were included. Successful reperfusion was defined as Thrombolysis in Cerebral Infarction grade ≥2b. A favourable clinical outcome was defined as a modified Rankin Score ≤2 at 3 months.

RESULTS

Between January 2009 and May 2012, 55 patients were treated with SR and 50 patients were treated with IAF. The baseline characteristics were similar between the two groups except for the occlusion site and rescue treatment. In binary logistic regression analysis adjusted for the occlusion site and rescue treatment, SR was independently associated with increased successful reperfusion [82.0% vs. 47.3%; odds ratio (OR) 5.21; 95% confidence interval (CI) 1.92-14.14) and a more favourable clinical outcome at 3 months (54.0% vs. 43.6%; OR 3.40; 95% CI 1.31-8.84). The frequency of symptomatic intracranial haemorrhage and mortality at 3 months was not different between the two groups.

CONCLUSIONS

Stent retriever was as safe as and more effective than IAF. Our findings suggest that SR may be considered as an initial modality rather than IAF in acute stroke patients who undergo endovascular treatment.

Management of gastric epithelial neoplasia in patients requiring esophagectomy for esophageal cancer

Esophageal squamous cell carcinoma is occasionally associated with malignancies located in other regions of the alimentary tract, as well as in the head, neck, and upper respiratory tract. The stomach is most commonly used for reconstruction of the alimentary tract after esophagectomy for esophageal cancer. When synchronous tumors are located in the stomach, it is often unsuitable for use in esophageal reconstruction. In such cases, an invasive procedure involving anastomosis between the esophagus and the colon must be performed. However, this procedure is associated with a high incidence of mortality and morbidity. Seven patients with synchronous esophageal cancer and gastric epithelial neoplasia were encountered. First, endoscopic submucosal dissection (ESD) was performed for the gastric epithelial neoplasia. Then, following successful ESD, Ivor-Lewis esophagectomy for esophageal cancer was planned 1 to 2 weeks later. A total of 11 gastric epithelial lesions were found in seven patients. En bloc resection by ESD was possible in all 11 lesions and histologically complete resection was achieved in all 11 lesions. Follow-up endoscopy was done 1-2 weeks after ESD; six patients with well-healing ulcers underwent esophagectomy the next day (8 or 15 days after ESD). In one patient with a poorly healed ulcer, a second follow-up endoscopy was done 1 week later and then esophagectomy was performed the next day (22 days after ESD). Post-surgical complications related to ESD, such as bleeding or mediastinal leak, were not seen in any of the seven patients. In patients with synchronous esophageal cancer and gastric epithelial neoplasia, ESD for gastric epithelial neoplasia followed by Ivor-Lewis esophagectomy 1 to 2 weeks later is an effective choice of treatment.

Ultra-low gamma-ray measurement system for neutrinoless double beta decay

An experiment for the detection of 0νβ(+)/EC and 0νEC/EC in 92Mo nuclei has been carried out with a scintillating crystal, CaMoO4, in coincidence with the HPGe detector. We study the background events inside the event selection window for 0ν β(+)/EC decays of CaMoO4 detector. For 51.2 days of data taking period, we didn't observe any event in the neutrinoless EC/EC decay event window. The (92)Mo 0νβ(+)/EC decay half-life limit was set to 0.61×10(20) years with a 90% confidence by method of Feldman and Cousins. This ultra-low gamma ray measurement utilizing coincidence technique can be used for the resonant EC/EC decay process of some nuclei which is potentially important for neutrinoless double beta decay process.

The role of external defects in chemical sensing of graphene field-effect transistors

A fundamental understanding of chemical sensing mechanisms in graphene-based chemical field-effect transistors (chemFETs) is essential for the development of next generation chemical sensors. Here we explore the hidden sensing modalities responsible for tailoring the gas detection ability of pristine graphene sensors by exposing graphene chemFETs to electron donor and acceptor trace gas vapors. We uncover that the sensitivity (in terms of modulation in electrical conductivity) of pristine graphene chemFETs is not necessarily intrinsic to graphene, but rather it is facilitated by external defects in the insulating substrate, which can modulate the electronic properties of graphene. We disclose a mixing effect caused by partial overlap of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of adsorbed gas molecules to explain graphene's ability to detect adsorbed molecules. Our results open a new design space, suggesting that control of external defects in supporting substrates can lead to tunable graphene chemical sensors, which could be developed without compromising the intrinsic electrical and structural properties of graphene.

The association between asymptomatic coronary artery disease and CHADS2 and CHA2 DS2 -VASc scores in patients with stroke

BACKGROUND AND PURPOSE

CHADS2 and CHA2 DS2 -VASc scores are measurement tools that stratify thromboembolic risk in patients with non-valvular atrial fibrillation, and are predictive of cerebral atherosclerosis, fatal stroke and ischaemic heart disease. Patients with higher CHADS2 and CHA2 DS2 -VASc scores are more likely to have had an akinetic/hypokinetic left ventricular segment or a recent myocardial infarction, all of which are associated with coronary artery disease (CAD). Most of the CHADS2 score components are also risk factors for atherosclerosis. Thus, CHADS2 and CHA2 DS2 -VASc scores may be predictive of CAD.

METHODS

In all, 1733 consecutive patients with acute ischaemic stroke who underwent multi-slice computed tomography coronary angiography were enrolled. The association of CHADS2 and CHA2 DS2 -VASc scores with the presence and severity of CAD was investigated.

RESULTS

Of the 1733 patients, 1220 patients (70.4%) had any degree of CAD and 576 (33.3%) had significant CAD (≥ 50% stenosis in at least one coronary artery). As the CHADS2 and CHA2 DS2 -VASc scores increased, the presence of CAD also increased (P < 0.001). The severity of CAD was correlated with CHADS2 score (Spearman coefficient 0.229, P < 0.001) and CHA2 DS2 -VASc score (Spearman coefficient 0.261, P < 0.001). In multivariate analysis, after adjusting for confounding factors, CHADS2 and CHA2 DS2 -VASc scores ≥2 were independently associated with CAD. The CHA2 DS2 -VASc score was a better predictor of the presence of CAD than the CHADS2 score on area under the curve analysis.

CONCLUSION

CHADS2 and CHA2 DS2 -VASc scores were predictive of the presence and severity of CAD in patients with stroke. When a patient has high CHADS2 or CHA2 DS2 -VASc scores, physicians should consider coronary artery evaluation.

Comparison of chest digital tomosynthesis and chest radiography for detection of asbestos-related pleuropulmonary disease

AIM

To compare chest digital tomosynthesis (DTS) with digital radiography for the detection of asbestos-related pleuropulmonary disease.

MATERIALS AND METHODS

The institutional review board approved this study and all participants gave informed consent. Forty-five participants with a history of asbestos exposure were examined with DTS and radiography. Low-dose multidetector computed tomography (CT) in the prone position served as the reference. Two observers evaluated all images for the presence of pleural abnormalities and asbestosis. Interobserver agreement was analysed by using the k statistic. Diagnostic performance of the two imaging methods was compared using McNemar's test.

RESULTS

Interobserver agreement regarding DTS findings was moderate to very good (k = 0.544-0.846) and superior to the radiographic findings (k = 0.236-1.000). Overall, the diagnostic accuracy of DTS for the lesion detection was significantly better than with radiography (all p < 0.05, except that for the comparison of diagnostic accuracy of DTS versus radiographic detection of left diaphragmatic plaques and asbestosis). DTS was more sensitive than radiography for the detection of asbestosis (82% versus 27%, p = 0.031).

CONCLUSION

DTS is more accurate than radiography in the detection of pleural plaques and more sensitive than radiography in the detection of asbestosis. Interobserver agreements with respect to the DTS findings were superior to the radiographic findings.

The frequency of cerebral microbleeds increases with CHADS(2) scores in stroke patients with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMBs) are extravasations of blood from lipohyalinized or amyloid angiopathic cerebral arterioles, and the presence and numbers of CMBs are significantly associated with the development of oral anticoagulation (OA)-related intracranial haemorrhage (ICH). The aim of this study was to investigate whether there is a difference in CMBs burden according to CHADS(2) scores or CHA(2) DS(2) -VASc scores in non-valvular atrial fibrillation (NVAF) patients.

METHODS

We included 550 ischaemic stroke patients who had NVAF and who had undergone brain magnetic resonance imaging (MRI) with gradient-recalled echo (GRE) T2 sequences from our prospective stroke registry between January 2005 and November 2011. We calculated CHADS(2) scores and CHA(2) DS(2) -VASc scores for all patients based on their underlying cardiovascular diseases. The presence, location and number of CMBs were assessed in each patient. We also investigated whether the CMBs were actually associated with the development of ICH during follow-up.

RESULTS

The mean patient age was 70.4 ± 10.5 years, and 324 (58.9%) patients were men. One-hundred and seventy-three patients (31.5%) had CMBs detected on GRE MRI. Higher CHADS(2) scores or CHA(2) DS(2) -VASc scores were strongly associated with the presence and number of CMBs. During follow-up of median 3.1 ± 1.6 years, the presence of CMBs was independently associated with the development of ICH, whilst the CHADS(2) scores or CHA(2) DS(2) -VASc scores were not.

CONCLUSIONS

Considering the positive association between the presence of CMBs and OA-related ICH, our results suggest that the increase in ICH in high-risk groups during OA may be related to an increased burden of CMBs.

Proteins involved in DNA damage response pathways and survival of stage I non-small-cell lung cancer patients

BACKGROUND

Biological complexity leads to significant variation in the survival of patients with stage I non-small-cell lung cancer (NSCLC). DNA damage response (DDR) pathways play a critical role in maintaining genomic stability and in the progression of NSCLC. Therefore, the development of a prognostic biomarker focusing on DDR pathways is an intriguing issue.

PATIENTS AND METHODS

Expression of several proteins (ATM, ATMpS1981, γH2AX, 53BP1, 53BP1pS25, Chk2, Chk2pT68, MDC1, MDC1pS964, BRCA1pS1423, and ERCC1) and overall survival were investigated in 889 pathological stage I NSCLC patients.

RESULTS

Low expression of BRCA1pS1423 or ERCC1 was significantly associated with worse survival in the whole cohort of patients. Analysis performed based on histology revealed that low expression of γH2AX, Chk2pT68, or ERCC1 was a poor prognostic factor in squamous cell carcinoma patients [adjusted hazard ratio (aHR), Cox P: 1.544, 0.012 for γH2AX; 1.624, 0.010 for Chk2pT68; 1.569, 0.011 for ERCC1]. The analysis of the interaction between two proteins showed that this effect was more pronounced in squamous cell carcinoma patients. However, these effects were not detected in adenocarcinoma patients.

CONCLUSIONS

The proteins involved in DDR pathways exhibited differential expression between squamous cell carcinoma and adenocarcinoma and were important determinants of survival in stage I squamous cell carcinoma patients.

Observation of reactor electron antineutrinos disappearance in the RENO experiment

The RENO experiment has observed the disappearance of reactor electron antineutrinos, consistent with neutrino oscillations, with a significance of 4.9 standard deviations. Antineutrinos from six 2.8  GW(th) reactors at the Yonggwang Nuclear Power Plant in Korea, are detected by two identical detectors located at 294 and 1383 m, respectively, from the reactor array center. In the 229 d data-taking period between 11 August 2011 and 26 March 2012, the far (near) detector observed 17102 (154088) electron antineutrino candidate events with a background fraction of 5.5% (2.7%). The ratio of observed to expected numbers of antineutrinos in the far detector is 0.920±0.009(stat)±0.014(syst). From this deficit, we determine sin(2)2θ(13)=0.113±0.013(stat)±0.019(syst) based on a rate-only analysis.

New limits on interactions between weakly interacting massive particles and nucleons obtained with CsI(Tl) crystal detectors

New limits are presented on the cross section for weakly interacting massive particle (WIMP) nucleon scattering in the KIMS CsI(Tℓ) detector array at the Yangyang Underground Laboratory. The exposure used for these results is 24 524.3  kg·days. Nuclei recoiling from WIMP interactions are identified by a pulse shape discrimination method. A low energy background due to alpha emitters on the crystal surfaces is identified and taken into account in the analysis. The detected numbers of nuclear recoils are consistent with zero and 90% confidence level upper limits on the WIMP interaction rates are set for electron equivalent energies from 3 to 11 keV. The 90% upper limit of the nuclear recoil event rate for 3.6-5.8 keV corresponding to 2-4 keV in NaI(Tℓ) is 0.0098 counts/kg/keV/day, which is below the annual modulation amplitude reported by DAMA. This is incompatible with interpretations that enhance the modulation amplitude such as inelastic dark matter models. We establish the most stringent cross section limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses greater than 20  GeV/c2.

Metformin ameliorates IL-6-induced hepatic insulin resistance via induction of orphan nuclear receptor small heterodimer partner (SHP) in mouse models

AIMS/HYPOTHESIS

IL-6 is a proinflammatory cytokine associated with the pathogenesis of hepatic diseases. Metformin is an anti-diabetic drug used for the treatment of type 2 diabetes, and orphan nuclear receptor small heterodimer partner (SHP, also known as NR0B2), a transcriptional co-repressor, plays an important role in maintaining metabolic homeostasis. Here, we demonstrate that metformin-mediated activation of AMP-activated protein kinase (AMPK) increases SHP protein production and regulates IL-6-induced hepatic insulin resistance.

METHODS

We investigated metformin-mediated SHP production improved insulin resistance through the regulation of an IL-6-dependent pathway (involving signal transducer and activator of transcription 3 [STAT3] and suppressor of cytokine signalling 3 [SOCS3]) in both Shp knockdown and Shp null mice.

RESULTS

IL-6-induced STAT3 transactivation and SOCS3 production were significantly repressed by metformin, adenoviral constitutively active AMPK (Ad-CA-AMPK), and adenoviral SHP (Ad-SHP), but not in Shp knockdown, or with the adenoviral dominant negative form of AMPK (Ad-DN-AMPK). Chromatin immunoprecipitation (ChIP), co-immunoprecipitation (Co-IP) and protein localisation studies showed that SHP inhibits DNA binding of STAT3 on the Socs3 gene promoter via interaction and colocalisation within the nucleus. Upregulation of inflammatory genes and downregulation of hepatic insulin signalling by acute IL-6 treatment were observed in wild-type mice but not in Shp null mice. Finally, chronic IL-6 exposure caused hepatic insulin resistance, leading to impaired insulin tolerance and elevated gluconeogenesis, and these phenomena were aggravated in Shp null mice.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that SHP upregulation by metformin may prevent hepatic disorders by regulating the IL-6-dependent pathway, and that this pathway can help to ameliorate the pathogenesis of cytokine-mediated metabolic dysfunction.

Failure analysis of InGaN/GaN high power light-emitting diodes fabricated with ITO transparent p-type electrode during accelerated electro-thermal stress

We have investigated the high-temperature degradation of optical power as well as electrical properties of InGaN/GaN light-emitting diodes (LEDs) fabricated with ITO transparent p-electrode during accelerated electro-thermal stress. As the thermal stress increased from 150 degrees C to 250 degrees C at a electrical stress of 200 mA, the optical power of the LEDs was significantly reduced. Degradation of the optical power was thermally activated, with the activation of 0.9 eV. In addition, the activation energy of the degradation of optical power was fairly similar to that of the degradation of series resistance of the LEDs, 1.0 eV, which implies that the increase in the series resistance may result in the severe degradation of optical power. We also showed that the increase in the series resistance of the LEDs during the accelerated electro-thermal stress can be attributed to reduction of the active acceptor concentration in the p-type semiconductor layers and local joule heating due to the current crowding.

Use of a handheld, computerized device as a decision support tool for stroke classification

BACKGROUND

The Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification has been widely used to determine etiology of ischemic stroke. However, interrater reliability is known to be modest. The complexity of abstraction and the interpretation of various clinical and laboratory data might limit the accuracy of the TOAST classification. In this study, we developed a computerized clinical decision support system for stroke classification that can be used in a handheld device and tested whether this system can improve diagnostic accuracy and reliability.

METHODS

Based on the TOAST classification, a logical algorithm was developed and implemented on a handheld device, named iTOAST. After answering six questions using the touch interface, the stroke subtype result is displayed on the screen. Four neurology residents were randomly assigned to classify stroke subtypes using iTOAST or the conventional method (cTOAST). Using a crossover design, they classified the stroke subtypes of 70 patients. The standard subtypes were determined by three stroke experts. Correlated kappa coefficients using iTOAST compared with cTOAST were determined.

RESULTS

The kappa (SE) value of iTOAST [0.790 (0.041), 95% CI: 0.707-0.870] was higher than that of cTOAST [0.692 (0.046), 95% CI: 0.600-0.782] (P<0.001). Neither sequence (P=0.857) nor period effect (P=0.999) was observed.

CONCLUSIONS

The stroke classification tool using a handheld, computerized device was easy, accurate, and reliable over the conventional method. It may have additional benefit because a handheld, computerized device is accessible anytime and anywhere.

Early neurological outcomes according to CHADS2 score in stroke patients with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

A higher CHADS(2) score or CHA(2)DS(2)-VASc score is associated with an increased risk of ischaemic stroke in patients with non-valvular atrial fibrillation (NVAF). However, there are no data regarding early neurological outcomes after stroke according to the risk levels.

METHODS

In this study, a total of 649 stroke patients with NVAF were enrolled and categorized into three groups: low-risk (CHADS(2) score of 0-1), moderate-risk (CHADS(2) score 2-3), or high-risk group (CHADS(2) score ≥4). CHA(2)DS(2)-VASc score was divided into four groups including 0-1, 2-3, 4-5, and ≥6. We investigated whether there were differences in initial stroke severity, early neurological outcome, and infarct size according to CHADS(2) score or CHA(2)DS(2)-VASc score in stroke patients with NVAF.

RESULTS

The initial National Institutes of Health Stroke Scale (NIHSS) score was highest in high-risk group [9.5, interquartile range (IQR) 4-18], followed by moderate-risk (8, IQR 2-17) and low-risk group (6, IQR 2-15) (P=0.012). Likewise, initial stroke severity increased in a positive fashion with increasing the CHA(2)DS(2)-VASc score. During hospitalization, those in the high-risk group or higher CHA(2)DS(2)-VASc score had less improvement in their NIHSS score. Furthermore, early neurological deterioration (END) developed more frequently as CHADS(2) score or CHA(2)DS(2)-VASc score increased. Multivariate analysis showed being in the high-risk group was independently associated with END (OR 2.129, 95% CI 1.013-4.477).

CONCLUSIONS

Our data indicate that patients with NVAF and higher CHADS(2) score or CHA(2)DS(2)-VASc score are more likely to develop severe stroke and a worse clinical course is expected in these patients after stroke presentation.

Prediction of survival and cancer recurrence using F-18 FDG PET/CT in patients with surgically resected early stage (Stage I and II) non-small cell lung cancer

The aim of the current study was to investigate the prognostic value of SUV(max) in patients with completely resected early stage (stage I and II) NSCLC. A retrospective review identified 76 patients with surgically resected early (stage I and II) NSCLC who received F-18 FDG PET/CT at diagnosis of cancer. Survival analysis was conducted using Kaplan-Meier analysis, and survival curves stratified by age, sex, mediastinal lymph node involvement, SUV(max), and TNM staging were generated for estimation of overall survival and disease free survival (DFS). Independent predictive factors for survival were determined using Cox proportional hazard model. For overall survival, the median survival of the patients with tumor SUV(max)≤ 6.7 was 48.9 months and was significantly longer than the patients with tumor SUV(max)>6.7 (Log rank test, Χ²=18.01, p5.9. The median survival of the patients with tumor SUV(max)≤ 5.9 was 31.7 months (Log rank test, Χ²=16, p=0.0001). In conclusion, high FDG uptake measured by F-18 FDG PET/CT might have a prognostic value for overall survival and DFS in surgically resected early stage (stage I and II) NSCLC even after stratified by pathologic stages.

Analysis of 2D periodic nanostructures with an oxide overlayer via spectroscopic ellipsometry

The accurate nondestructive determination of the shapes or critical dimensions of periodic nanostructures is essential to the current integrated-circuits technology. Optical critical dimension (OCD) metrology is fast, nondestructive, and can be used in air, allows higher sampling rates compared to the non-optical methods such as scanning electron microscopy (SEM) or atomic-force microscopy (AFM), and does not damage the sample. The data are typically analyzed via rigorous coupled-wave analysis (RCWA), where the sample is modeled as a series of layers whose dimensional parameters are determined by a least-squares fit. The layers are typically approximated as a combination of core material and ambient. Oxide overlayers and surface roughness are common, however, and call into question two-phase approximation. In this study, a structure that is periodic in two dimensions and that is coated with a thin (3 nm) oxide was studied, and an extension of the RCWA method that allows structural information to be extracted from optical data even in the presence of oxide overlayers or surface roughness was developed.

Patient with positional wheezing due to endobronchial lipomatous hamartoma

Endobronchial hamartoma is a rare form of pulmonary hamartoma, and endobronchial lipomatous hamartomas are even rarer. We describe the case of a 39-year-old man who presented with a two-year history of dyspnea on exertion and wheezing over the left chest only while lying on his left side. The patient was diagnosed with endobronchial lipomatous hamartoma occluding the left main bronchus. He underwent a superior segmentectomy of the left lower lobe, which promptly relieved the dyspnea and positional wheezing. To our knowledge, fewer than 10 such cases are cited in the English literature, none of which presented with positional wheezing. This patient represents the first case of focal and positional wheezing resulting from endobronchial lipomatous hamartoma.

Effect of warfarin withdrawal on thrombolytic treatment in patients with ischaemic stroke

BACKGROUND AND PURPOSE

  Abruptly discontinuing warfarin may induce a rebound prothrombotic state. Thrombolytic agents may also paradoxically induce prothrombotic conditions, which include platelet activation and thrombin generation. Therefore, prothrombotic states may be enhanced by withdrawing warfarin in patients under thrombolytic treatment. This study was aimed to determine whether patients with warfarin withdrawal have different clinical outcomes from those without warfarin use after thrombolytic treatment.

METHODS

  A total of 148 consecutive patients with atrial fibrillation who were not on anticoagulants at admission and who received thrombolysis were included in this study. We compared the outcomes between a warfarin withdrawal group and a no-warfarin group.

RESULTS

  Fourteen patients (9.5%) were included in the warfarin withdrawal group. Although baseline National Institute of Health Stroke Scale (NIHSS) scores, recanalization rates, and hemorrhage frequencies did not differ between the groups, the warfarin withdrawal group showed poorer outcomes. Increased NIHSS scores during the first 7days were more frequent in the warfarin withdrawal group (57.1% vs. 26.9%, P=0.029). The median percent improvement in NIHSS scores at 24h after thrombolysis was also lower in the warfarin withdrawal group. After adjusting for covariates, warfarin withdrawal was a strong predictor of poor functional outcome at 3months (modified Rankin score≥3) (odds ratio, 17.067, 95% CI 2.703-107.748).

CONCLUSIONS

  Discontinuing warfarin was associated with early neurologic deterioration and poor long-term outcomes after thrombolytic treatment.