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Statement of problem Internal conical connections have become the primary choice for implant-supported restorations. However, studies that identified the risk indicators for mechanical complications and diagnosed the prognosis of the implant-supported restorations are lacking. Purpose The purpose of this retrospective clinical study was to evaluate the incidence and consequences of mechanical complications in components of internal conical connection implants and to analyze the risk indicators. Material and methods A total of 428 patients with 898 internal conical connection implants were included in the study, and mechanical complications over the 14-year observation period were evaluated. The Cox proportional hazard regression model was used to analyze significant effects on mechanical complications, which were presented as hazard ratio and 95% confidence interval. Results Mechanical complications occurred in 430 (47.9%) implants and 248 (57.9%) patients: screw loosening (46.4% of implants, 56.8% of patients); screw fracture (2.6% of implants, 4.4% of patients); abutment fracture (11.4% of implants, 21.3% of patients); and implant fracture (3.5% of implants, 5.4% of patients). Implant restorations replacing molars showed the highest risk for mechanical complication (hazard ratio 12.82; 95% confidence interval 2.73-60.31) and for fracture of all components. Men had a higher risk of mechanical complication than women (hazard ratio 2.00; 95% confidence interval 1.55-2.59), and the risk of fracture was higher in all components. With increased splinted implants, the risk of mechanical complication (hazard ratio 0.67; 95% confidence interval 0.49-0.93) and component fracture (hazard ratio 0.73; 95% confidence interval 0.29-0.89) decreased. Gold screws had a lower risk of screw loosening (hazard ratio 0.74; 95% confidence interval 0.58-0.94) than titanium screws, but a higher risk of fracture (hazard ratio 3.45; 95% confidence interval 1.42-8.36). The smaller the implant diameter, the higher the risk of implant fracture (hazard ratio 0.01; 95% confidence interval 0.00-0.05). Conclusions Abutments were most frequently fractured among the components of internal conical connection type implants. Molar implant-supported restorations and male patients had higher risks of mechanical complications, and as the number of splinted implants in a prosthesis increased, the risk decreased. Gold screws showed less risk of screw loosening and higher risk of fracture than titanium screws. Narrow-diameter implants had a higher risk of fracture.

The satisfaction of a software requirement is commonly stated as a Boolean value, that is, a security requirement is either satisfied (true) or not (false). However, a discrete Boolean value to measure the satisfaction level of a security requirement by deployed mechanisms is not very useful. Rather, it would be more effective if we could quantify the level of satisfaction of security requirements on a continuous scale. We propose an approach to achieve this for cloud software systems based on relationships between defense strength, exploitability of vulnerabilities, and attack severity. We extend the concept of entailment relationship from the field of requirements engineering with the satisfiability aspects of security requirements. The proposed approach enables us to systematically structure security concepts into three sets of related descriptions to quantify the satisfaction level of security requirements with the deployed security solutions. To demonstrate the feasibility of the proposed approach, we evaluate the approach in a case study. As a result, security administrators are able to deploy more effective and appropriate security solutions based on their assessment.

Recent technical innovation has driven the evolution of autonomous vehicles. To improve safety as well as on-road vehicular experience, vehicles should be connected with each other or to vehicular networks. Some specification groups, e.g., IEEE and 3GPP, have studied and released vehicular communication requirements and architecture. IEEE's Wireless Access in Vehicular Environment focuses on dedicated and short-range communication, while 3GPP's New Radio V2X supports not only sidelink but also uplink communication. The 3GPP Release 16, which supports 5G New Radio, offers evolved functionalities such as network slice, Network Function Virtualization, and Software-Defined Networking. In this paper, we define and design a vehicular network architecture compliant with 5G core networks to enable and support autonomous driving. As a validation example, a high-definition map needs to contain the context of trajectory for localization and planning of autonomous driving vehicles. We also propose new methods by which autonomous vehicles can push and pull map content efficiently, without causing bottlenecks on the network core. We evaluate the performance of the proposed method via network simulations and our autonomous driving vehicle on the road. Experimental results indicate that the proposed method improves the performance of vehicular content delivery in real-world road environments.

Background/Aims Endoscopic ultrasonography (EUS) provides high-resolution images and is superior to computed tomography (CT) scan in diagnosing small pancreatic ductal adenocarcinoma (PDAC). As a result, the use of EUS for early detection of PDAC has attracted attention. This study aimed to identify the clinical and radiological characteristics of patients with PDAC diagnosed by EUS but not found on CT scan. Methods The medical records of patients diagnosed with PDAC at 12 tertiary referral centers in Korea from January 2003 to April 2019 were reviewed. This study included patients with pancreatic masses not clearly observed on CT scan but identified on EUS. The clinical characteristics and radiological features of the patients were analyzed, and survival analysis was performed. Results A total of 83 patients were enrolled. The most common abnormal CT findings other than a definite mass was pancreatic duct dilatation, which was identified in 61 patients (73.5%). All but four patients underwent surgery. The final pathologic stages were as follows: IA (n=31, 39.2%), IB (n=8, 10.1%), IIA (n=20, 25.3%), IIB (n=17, 21.5%), III (n=2, 2.5%), and IV (n=1, 1.4%). The 5-year survival rate of these patients was 50.6% (95% confidence interval, 38.8% to 66.7%). Elevated liver function testing and R1 resection emerged as significant predictors of mortality in the multivariable Cox regression analysis. Conclusions This multicenter study demonstrated favorable long-term prognosis in patients with PDAC diagnosed by EUS but indeterminate on CT scan. EUS should be considered for patients with suspected PDAC but indeterminate on CT scan.

The relationship between fasting blood glucose (FBG) variability and colorectal cancer (CRC) remains ill-defined. This study aimed to evaluate the association of FBG variability with CRC risk in the healthy population without overt diabetes.In the data from the Korean National Health Insurance Service-Health Screening Cohort, we included individuals examined by FBG testing at least 3 times between 2002 and 2007. FBG variability was calculated using standard deviation (SD) and coefficient of variation (CV).Regarding FBG variability, an increase in the quintile of SD or CV was independently associated with CRC risk (all p for trend0.01). When the change in FBG was classified into six trajectory patterns, unfavorable trajectory patterns (high stable and upward) were significantly associated with increased CRC risk (hazard ratio [HR] 2.30, p=0.003; HR 1.19, p=0.007, respectively). In subgroup analyses according to the sex, a significant association between FBG variability (SD or CV) and CRC risk was observed in men but not in women. The high stable and upward pattern were also associated with CRC risk in men (HR 2.47, p=0.002; HR 1.21, p=0.012) but not in women.This study identified that FBG variability and unfavorable trajectory patterns were significantly associated with increased CRC risk in the healthy population without overt diabetes. Our findings suggest that FBG variability as well as FBG itself may be a predictive factor for the development of CRC.

Residual functional ankle instability regardless of the restoration of mechanical stability after the lateral ligament repair or reconstruction can cause recurrent sprain. The purpose of this study was to identify the sequential changes of joint-position sense, peroneal strength, postural control, and functional performance ability after the modified Broström procedure (MBP) for chronic ankle instability. A total of 46 patients (46 ankles) underwent the MBP for chronic ankle instability were eligible for this study and were followed for 1 year postoperatively. The changes of joint-position sense and peroneal strength were periodically evaluated with an isokinetic dynamometer. Postural control ability was evaluated using a one-leg stance test with eyes closed. The functional performance ability examination comprised a one-leg hop test, a 6-meter hop test, and a cross 3-meter hop test. The error in joint-position sense significantly improved from a mean 4.3º to 2.8º (p.001). Peak torque for eversion significantly improved from a mean 18.2 Nm to 21.2 Nm (p = .024). Balance retention time significantly improved from a mean 4.7 seconds to 6.4 seconds (p.001). Among the functional performance tests, only the one-leg hop test showed a significant improvement postoperatively (p = .031). At 1 year postoperatively, the recovery ratios compared to the unaffected ankle were 67.9% in joint-position sense (p.001), 86.9% in peroneal strength (p = .012), and 74.4% in postural control (p.001) with significant side-to-side differences. Although joint-position sense, peroneal strength, postural control, and functional performance ability were significantly improved after the MBP, recovery ratios compared to the unaffected ankle were insufficient up to 1 year postoperatively.

Background/Aims: The preventive role of hydroxychloroquine (HCQ) on coronavirus disease 2019 (COVID-19) remains unclear. The aim of this study was to examine the effects of HCQ and other immunosuppressive drugs on the incidence of COVID-19.Methods: The data were collected from the South Korea National Health Insurance Sharing-COVID-19 database. All individuals who underwent nasopharyngeal and oropharyngeal swab tests for COVID-19 from January 2020 to May 2020 are included. The association between COVID-19 risk and HCQ use was examined in a propensity score-matched population. Factors associated with COVID-19 were identified using multiple logistic regression analysis.Results: Total 8,070 patients with COVID-19 and 121,050 negative controls were included from the database. Among all participants, 381 were HCQ users. In a propensity score-matched population, the incidence of COVID-19 was 7.1% in HCQ users and 6.8% in non-users. The odds ratio (OR) for HCQ use was 1.05 with a 95% confidence interval (CI) of 0.58 to 1.89. Among the subpopulation of patients with rheumatoid arthritis (RA), 33 were diagnosed with COVID-19 and 478 were not. Use of HCQ, glucocorticoids, or other immunosuppressive drugs was not associated with COVID-19 risk, whereas abatacept use was. Chronic lung disease was an independent risk factor for COVID-19 diagnosis in patients with RA (adjusted OR, 6.07; 95% CI, 1.10 to 33.59).Conclusions: The risk of COVID-19 did not differ between HCQ users and non-users. Glucocorticoids, conventional disease-modifying antirheumatic drugs (DMARDs), and biological DMARDs other than abatacept did not increase the risk of COVID-19.

The aim of this study was to investigate the relationships between the stages of calcification of various teeth and skeletal maturity stages among Korean subjects. The samples were derived from hand-wrist, panoramic radiographs, and lateral cephalograms of 743 subjects (359 males and 384 females) with ages ranging from 6 to 14 years. Calcification of seven permanent mandibular teeth on the left side were rated according to the system of Demirjian. To evaluate the stage of skeletal maturation, hand-wrist radiographs were analyzed by skeletal maturity indicators (SMI) system of Fishman and lateral cephalograms by cervical vertebral maturation (CVM) method of Baccetti. Statistically significant relationships were found between dental calcification and skeletal maturity stages according to Spearman rank-order correlation coefficients (r = 0.40-0.84, p < 0.001). The second molar showed the highest correlation and central incisor showed the lowest correlation for female and male subjects. For both sexes, canine stage G and second molar stage F were related to SMI 6 and CS 3. Because of the high correlation coefficients, this study suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period in Korean patients.

To evaluate the morphologic features of macular neovascularization (MNV) trunks at different layers using optical coherence tomography angiography.Type 1 MNV trunks in age-related macular degeneration were retrospectively evaluated at the subretinal pigment epithelium and sub-Bruch membrane (subBM) layers. The detectability and location of the trunks were compared. MNV trunks at the subBM layer on optical coherence tomography angiography B-scans were evaluated using a flow overlay. The correlations of the MNV trunk with optical coherence tomography angiography and optical coherence tomography parameters were evaluated.Among the 63 included eyes, 27 showed core vessels at the subretinal pigment epithelium layer and 52 showed MNV trunks at the subBM layer, which were connected with the MNV at the subretinal pigment epithelium layer. The locations of the MNV trunks in each layer were different. MNV trunk types at the subBM layer were related to disease duration, distance from the large choroidal vessels, and MNV vessel density. The large choroidal vessel diameter was correlated with the MNV trunk diameter at the subBM layer.Macular neovascularization trunks at the subBM layer were detected more frequently than distal MNV trunks at the subretinal pigment epithelium layer. Macular neovascularization trunk features at the subBM layer may be related to disease duration and a large choroidal vessel.

Topic Comparative efficacy and safety of different concentrations of atropine for myopia control in children. Clinical relevance Atropine is known to be an effective intervention to delay childhood myopia progression. Nonetheless, there is as yet no well-supported evidence ranking the clinical outcomes of various concentrations of atropine. Methods We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, WHO International Clinical Trials Registry Platform and ClinicalTrials.gov on Apr 14, 2021. We selected studies involving atropine treatment of at least 1-year duration for control of myopia in children. We performed a network meta-analysis (NMA) of placebo-controlled and head-to-head randomized controlled trials (RCTs) and compared 8 atropine concentrations (1, 0.5, 0.25, 0.1, 0.05, 0.025, 0.02, and 0.01%). We ranked the atropine concentrations for the corresponding outcomes by P-score (estimate of probability of being best treatment). Our primary outcomes were mean annual changes in refraction (diopters/year) and axial length ([AXL] millimeters/year). We also extracted data on the proportion of eyes showing myopia progression and safety outcomes (photopic/mesopic pupil diameter, accommodation amplitude, distance/near best-corrected visual acuity [BCVA]). Results Thirty (30) pairwise comparisons from 16 RCTs (3,272 participants) were obtained. Our NMA ranked the 1, 0.5 and 0.05% atropine concentrations as the 3 most beneficial for myopia control based on P-scores, as assessed for both primary outcomes: 1% atropine (mean difference and 95% CI in refraction compared to control: 0.81 [0.58;1.04]; AXL: -0.35 [-0.46;-0.25]), 0.5% atropine (refraction: 0.70 [0.40;1.00]; AXL: -0.23 [-0.38;-0.07]), 0.05% atropine (refraction: 0.62 [0.17;1.07]; AXL: -0.25 [-0.44;-0.06]). In terms of myopia control as assessed by relative risk (RR) for overall myopia progression, 0.05% was ranked as the most beneficial atropine concentration (RR:0.39 [95% CI: 0.27;0.57]) followed by 1% (0.43 [0.33;0.56]). The ranking probability for adverse effects (photopic/mesopic pupil diameter and accommodation amplitude) tended to decline as the atropine concentration was increased, though this tendency was not evident for distance BCVA. No valid network was formed for near BCVA. Conclusion The ranking probability for efficacy was not proportional to dose (i.e., 0.05% atropine was comparable to that of high-dose [1 and 0.5%]), though those for pupil size and accommodation amplitude were dose-related.

A mercury sphygmomanometer (MS) has been the gold standard for pediatric blood pressure (BP) measurements, and diagnosing hypertension is critical. However, because of environmental issues, other alternatives are needed. Non-invasive BP measurement devices are largely divided into auscultatory and oscillometric types. The aneroid sphygmomanometer, the currently used auscultatory method, is inferior to mercury sphygmomanometers in terms of limitations such as validation and regular calibration and difficult to apply to infants, in whom Korotkoff sounds are not audible. The oscillometric method uses an automatic device that eliminates errors caused by human observers and has the advantage of being easy to use; however, owing to its measurement accuracy issues, the development of an international validation protocol for children is important. The hybrid method, which combines the auscultatory and electronic methods, solves some of these problems by eliminating the observer bias of terminal digit preference while maintaining measurement accuracy; however, the auscultatory method remains limited. As the age-related characteristics of the pediatric group are heterogeneous, it is necessary to reconsider the appropriate BP measurement method suitable for this indication. In addition, the mobile application-based BP measurement market is growing rapidly with the development of smartphone applications. Although more research is still needed on their accuracy, many experts expect that mobile application-based BP measurement will effectively reduce medical costs due to increased ease of access and early BP management.

Controlling transverse discrepancies is necessary to ensure stable and functional occlusion. Altered molar inclinations can camouflage the transverse relationship. The purpose of this research was to evaluate the maxillomandibular relationship of the center of resistance (CR) of the arch form created by the CR of teeth and compare these CR arch forms by their skeletal patterns.Sixty patients with minor crowding and normal posterior overjet were divided into 3 groups according to ANB angle: skeletal Class I group had ANB angle between 0° and 4° (n = 20), skeletal Class II group had ANB angle 4° (n = 20), and skeletal Class III group had ANB angle 0° (n = 20). The 3-dimensional coordinates of the CR were estimated using cone-beam computed tomography images and projected on the CR occlusal plane to obtain the 2-dimensional coordinates. The CR arch forms were constructed and evaluated using Matlab (MathWorks, Natick, Mass).On comparing maxillomandibular CR arch form widths, the maxilla was significantly larger than the mandible of the canine and first premolar. The mandible was larger in the first molar of the skeletal Class III group. The maxillomandibular CR arch form width ratios were between 0.97 and 1.35. On comparing maxillomandibular CR arch form areas, the maxilla was significantly larger than the mandible in the anterior segment, and the mandible was larger in the posterior segment. The ratios were between 0.86 and 2.25. In between-group comparison, the skeletal Class III group showed significantly greater arch forms in the mandible.CR arch forms had significant maxillomandibular differences throughout the arch. The maxillomandibular ratios could be a reference for site-specific transverse discrepancy analysis.

Background Methamphetamine (METH) is the most widely used psychostimulant and has been known to exhibit reinforcing effects even after long abstinence. We showed the inhibitory effect of Korean Red Ginseng extract (RGE) on METH-induced addictive behaviors in animal models mimicking the human drug-use pattern. Methods We first investigated the effect of RGE on the acquisition of METH-induced dependence using self-administration and conditioned place preference (CPP) tests. Additionally, further experiments such as METH-induced motivational behavior and seeking behavior were conducted. To study the underlying mechanism, dopamine receptor, dopamine transporter, and N-methyl-D-aspartate receptor were assessed through Western blot analysis. Results Treatment with RGE significantly reduced METH-induced self-administration on a fixed-ratio 1 schedule of reinforcement. It could be also decreased a progressive ratio schedule, and inhibited METH-primed reinstatement. In CPP, RGE significantly prevented the development of METH-induced CPP. Moreover, RGE not only shortened the withdrawal period clearly, but also prevented the reinstatement of CPP. RGE treatment also reversed METH-induced overexpression of dopamine transporter, dopamine receptor D1, and NMDA receptor in the nucleus accumbens. Conclusion Our findings reflect that RGE has therapeutic potential to suppress METH-induced addictive behaviors by regulating dopaminergic and NMDAergic system., Graphical abstract Image 1

Button battery ingestion requires emergency endoscopic removal since severe complications, such as esophageal perforation, can develop within 4 hours of the ingestion. Given that guardians do not witness the children’s foreign body ingestion 40% of the time, physicians can only guess what was swallowed based on plain radiography. We report a case of a 45-month-old-boy who visited the emergency department after swallowing an unknown foreign body and whose radiographs showed “circle-within-a-circle appearance” on the anteroposterior view and “step-off appearance” on the lateral view, suggesting button battery ingestion. We conducted emergency endoscopic removal, and found stacked coins mimicking a button battery on the radiographs. The coins were pushed into the stomach and came out through defecation 3 weeks later without further complications. Distinguishing between stacked coins and a button battery through radiography may help avoid unnecessary emergency endoscopy.

Purpose: To evaluate the changes in eyelid parameters after the endonasal approach compared with transcaruncular medial wall decompression combined with the transconjunctival inferior wall decompression approach with inferomedial strut preservation.Methods: In total, 71 patients with thyroid eye disease who underwent orbital decompression were retrospectively evaluated. The data collected included Hertel exophthalmometry, marginal reflex distance 1, marginal reflex distance 2, interpalpebral fissure, levator function test measures, and complications related to surgery.Results: Proptosis reduction produced a statistically significant improvement across all decompression groups. Lower eyelid retraction produced a statistically significant improvement in the two-wall decompression groups but not in the one-wall decompression groups. No statistical difference was observed in the upper eyelid retraction and levator function after surgery across all decompression groups. In the post-hoc analysis, statistical improvement was not observed in the lower eyelid retraction between the endonasal and transcaruncular approach in the one-wall and two-wall decompression groups, although statistically significant exophthalmos reduction and improvement in the lower eyelid retraction was noted in the two-wall decompression subgroups compared with one-wall decompression subgroups.Conclusions: Our study showed no differences in eyelid parameters between the endonasal and transcaruncular decompression approaches in one-wall and two-wall decompression. In the two-wall decompression group, proptosis reduction was greater with the endonasal approach than with the transcaruncular approach when the strut was preserved; however, it does not lead to a significant difference in the improvement of lower eyelid retraction.

Following the permanent shutdown of Kori Unit 1 in June 2017, the Republic of Korea has been preparing for full‐scale decommissioning work. In addition, the design life of 12 units will expire by 2030. If decommissioning begins without initially extending the lifespan of nuclear reactors, massive amounts of decommissioning wastes will be generated in a short period. The total amount of radioactive wastes generated during the dismantling of a pressurized water reactor is estimated as 6200 tons, and approximately 70% of the total radioactive wastes are classified as metal wastes. Self‐disposal through the decontamination of contaminated metals can contribute to the economic feasibility of decommissioning nuclear power plants because it can reduce the disposal cost of medium‐ and low‐level radioactive wastes. Therefore, this study evaluated the possibility of self‐disposal of steam generators that may occur during future decommissioning. The radioactivity analysis data on transferring the replaced steam generator of Hanul Unit 1 were used as the source term. The decontamination factor was calculated by applying 200 units from 1200 to 2000, and the radiation dose was evaluated using the RESRAD‐RECYCLE code. Consequently, the single‐nuclide concentration and sum of the allowable concentration fraction for mixed radionuclides at a decontamination factor of 1400 were below the regulatory requirements; however, the dose evaluation results exceeded the allowable dose in some scenarios. The decontamination factor was 2000, when the dose evaluation results for all scenarios met the regulatory requirements.

Introduction The purpose of this study was to analyze the treatment effects after molar distalization using modified C-palatal plates with and without second molar eruption and, to evaluate the three-dimensional position of the molars during long-term retention using cone-beam computed tomography. Methods The study sample comprised 74 third molars in 42 patients. Twenty-seven adolescent patients (mean age, 12.6 years) having 48 maxillary third molars were divided into 2 groups according to the eruption of their second molars: 15 patients with second molar eruption (group 1) and 12 patients without second molar eruption (group 2). Pretreatment, posttreatment, and long-term data (mean, 5.2 years) from cone-beam computed tomography were scanned and compared with control groups. Results There was less tipping movement of the first and second molars (0.94° and 3.22°) and distal tipping movement of the third molars (8.91°) in group 1 than in group 2 (4.36°, 7.39°, and 3.08°, respectively), but the treatment time was shorter and the positional change of the third molars was insignificant in group 2. In the long-term, the second molars fully erupted after distalization in group 2, and there was no difference in the third molar position between group 1, group 2, and the control group, except for the vertical position of the third molars in group 1. Conclusions In the long-term, the second molars fully erupted after distalization, and the third molars were in a favorable position. Therefore, these findings suggest that clinicians do not need to extract developing third molars before distalization in adolescents.

The purpose of this study was to determine whether statins can enhance anticancer effects in head and neck squamous cell carcinoma (HNSCC) when used with cisplatin and act as immunogenic cell death (ICD) inducers that can be used in cancer immunotherapy. Statins alone showed both in vitro and in vivo inhibitory effects against HNSCC, and synergistic antitumor effects were observed when combined with cisplatin in a syngeneic murine HNSCC model. Statins increased calreticulin exposure and endoplasmic reticulum stress-related signals in HNSCC cells. In addition, it was confirmed that statins could activate antigen-presenting cells and tumor-specific CD8+ T cells with an increase in their numbers in the tumor tissues and draining lymph nodes, with this effect showing significant improvement following the combination therapy with cisplatin. Moreover, in triple combination with both cisplatin and anti-programmed cell death 1 receptor (anti-PD-1) antibody, statins dramatically induced further tumor eradication and improved the survival of tumor-bearing mice. Taken together, these results demonstrate that statins, administered in combination with anti-PD-1 antibody, could enhance the anticancer effect of cisplatin and potentiate the efficacy of immunotherapy for HNSCC and present a rationale for repurposing statins as an adjuvant immunotherapeutic option for HNSCC.

Pharyngoesophageal defects can cause exposure to various bacterial flora and severe inflammation. We fabricated a biodegradable polycaprolactone (PCL) patch composed of both thin film and three-dimensional (3D) printed lattice, and then investigated the efficacy of pharyngoesophageal reconstruction by using 3D printed antibiotic-releasing PCL patches that inhibited early inflammation by sustained tetracycline (TCN) release from both thin PCL films and printed rods implanted in esophageal partial defects. PCL was 3D printed in lattice form on a presolution casted PCL thin film at ∼100 μm resolution. TCN was loaded onto the PCL-printed patches by 3D printing a mixture of TCN and PCL particles melted at 100°C. TCN exhibited sustained release

In automotive frequency-modulated continuous wave radar systems, targets with similar ranges and velocities might be detected as a single target because their target information overlaps on the range-velocity (RV) plane. When the information of multiple targets overlaps on the RV plane, target classification cannot be performed accurately. Therefore, we propose a method to decompose the overlapped target information on the RV plane for effective target classification. To separate each target’s radar signal, we use an orthogonal projection, in which the steering vector formed from the angle information of the desired target is projected onto the kernel space composed of other steering vectors. To verify the performance of the proposed method, a convolutional neural network-based target classification is performed on the decomposed radar signals. Compared to the angle-fast Fourier transform (FFT)-based signal decomposition, the orthogonal projection-based signal decomposition shows higher classification accuracy, which implies that the target information overlapped on the RV plane is effectively separated. When information of two targets is overlapped, the classification accuracy of the proposed method is 5.9%p higher than that of the conventional method. Moreover, when the information of three targets is overlapped, the accuracy is improved by 25.5%p.

The objective of this study was to estimate the incidence of secondary cancers and the factors associated with their development among patients who underwent radioiodine therapy (RIT) with differentiated thyroid cancer. We retrospectively collected medical records for patients who underwent first RIT between January 1, 2000, and December 31, 2005, from seven tertiary hospitals in South Korea after total thyroidectomy for differentiated thyroid cancer. Cancer incidence and calculated standardized rate ratio were compared with Korean cancer incidence data. The association between the development of secondary cancers and various parameters was analyzed by Cox-proportional hazard regression. A total of 3106 patients were included in this study. Mean age at the time of diagnosis of thyroid cancer was 45.7 ± 13.3 years old, and 2669 (85.9%) patients were female. The follow-up period was 11.9 ± 4.6 (range, 1.2–19.6) years. A total of 183 secondary cancers, which included 162 solid and 21 hematologic cancers, occurred in 173 patients (5.6%). There was no significant difference between solid cancer incidence in our study population who underwent RIT and the overall Korean population, but the incidence of hematologic cancers and total cancer in our study was significantly higher compared with that of the Korean population. A multivariate analysis identified independent prognostic factors for the development of secondary cancer including age at 1st RIT, male, and total cumulative dose over 200 mCi. We need to assess the risk benefit for patients who receive over 200 mCi of a total cumulative dose.

Objectives We investigated differences in the ascending reticular activating system (ARAS) between vegetative state (VS) and minimally conscious state (MCS) in patients with traumatic brain injury (TBI) by using diffusion tensor tractography. Methods We recruited TBI patients and normal subjects. We reconstructed the lower ARAS and five parts of upper ARAS [prefrontal cortex (PFC), premotor cortex, primary motor cortex, primary somatosensory cortex, and posterior parietal cortex]. Results Significant differences were observed in the fractional anisotropy (FA) and fiber number (FN) values of the five parts of upper ARAS between the VS and control groups and between the MCS and control groups (P < 0.05), but no differences were detected in the lower ARAS (P > 0.05). The FA and FN values of the PFC in the upper ARAS were significantly different between the VS and MCS groups (P < 0.05). No other significant differences in FA and FN values were detected among the other segments of the upper ARAS or in the lower ARAS (P > 0.05). Conclusion The results indicate that the prefrontal portion of the upper ARAS is the critical area for distinguishing between VS and MCS in patients with TBI.

Purpose The aim of the current meta-analysis was to evaluate diagnostic accuracies of preoperative F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) for prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) patients. Methods The scientific database such as PubMed, Cochrane, and Embase database were searched for studies evaluating diagnostic accuracies of preoperative F-18 FDG PET or PET/CT for prediction of MVI in HCC patients up to November 30, 2020. Results Fourteen eligible studies (1276 patients) were enrolled. The pooled sensitivity for F-18 FDG PET or PET/CT was 0.67 (95% CI; 0.57–0.76) with heterogeneity and a pooled specificity of 0.80 (95% CI; 0.74–0.85) with heterogeneity. Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 3.3 (95% CI; 2.5–4.5) and negative likelihood ratio (LR−) of 0.41 (95% CI; 0.31–0.55). The pooled diagnostic odds ratio (DOR) was 8 (95% CI; 5–14). Summary receiver operating characteristic (ROC) curve indicates that the area under the curve was 0.81 (95% CI; 0.78–0.84). Conclusion The current meta-analysis showed a low sensitivity and moderate specificity of F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients. F-18 FDG PET or PET/CT might not be useful for the preoperative prediction of MVI in HCC patients and should not be used to exclude MVI. Therefore, cautious application and interpretation should be paid to the F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients preoperatively.

We present a 32.768 kHz crystal oscillator with ultra-low power operation and a fast startup featuring for IoT applications. A self-reference power gating scheme detects the amplitude of a clock, enabling a negative resistance booster to awake XO and keep the oscillation with a duty-cycling technique for minimizing power consumption. In addition, a relaxation oscillator injects in-band noise initially, further reducing the startup time. The prototype XO for proof-of-concept was fabricated in 0.11- $\mu \text{m}$ CMOS and fully characterized. It consumes 5.02 nW at 0.5-V supply and achieves the startup time of 1.26 s simultaneously.

Objective Recently, sirolimus has emerged as a safe and effective treatment modality for unresectable vascular lesions. In this study, we investigated the effectiveness and safety of sirolimus based an early experience with patients with unresectable vascular anomalies. Methods Medical records and radiological images of all patients with unresectable vascular anomalies treated with sirolimus at our center between January 2018 and November 2019 were retrospectively reviewed. All patients were administered oral doses of sirolimus 0.8 mg/m2 every twelve hours as the initial doses, and then target serum concentration was maintained (5–10 ng/ml) with therapeutic drug monitoring. Results Six patients with unresectable vascular anomalies were treated with sirolimus for 10 months or more. The median age at the initiation of sirolimus treatment was 17 months (range, 8–67 months). The median duration of treatment was 13 months (range, 10–16 months). One patient showed good response, and four showed intermediate response, while one patient had no response to sirolimus therapy. None of the patients discontinued sirolimus therapy because of adverse effects. Conclusions Sirolimus may be used effectively and safely in patients with unresectable vascular anomalies. However, further prospective studies are warranted to evaluate the long-term effects of sirolimus and clarify indications for early intervention.

Background/aims Several prediction models for evaluating the prognosis of nonmetastatic resected pancreatic ductal adenocarcinoma (PDAC) have been developed, and their performances were reported to be superior to that of the 8th edition of the American Joint Committee on Cancer (AJCC) staging system. We developed a prediction model to evaluate the prognosis of resected PDAC and externally validated it with data from a nationwide Korean database. Methods Data from the Surveillance, Epidemiology and End Results (SEER) database were utilized for model development, and data from the Korea Tumor Registry System-Biliary Pancreas (KOTUS-BP) database were used for external validation. Potential candidate variables for model development were age, sex, histologic differentiation, tumor location, adjuvant chemotherapy, and the AJCC 8th staging system T and N stages. For external validation, the concordance index (C-index) and time-dependent area under the receiver operating characteristic curve (AUC) were evaluated. Results Between 2004 and 2016, data from 9,624 patients were utilized for model development, and data from 3,282 patients were used for external validation. In the multivariate Cox proportional hazard model, age, sex, tumor location, T and N stages, histologic differentiation, and adjuvant chemotherapy were independent prognostic factors for resected PDAC. After an exhaustive search and 10-fold cross validation, the best model was finally developed, which included all prognostic variables. The C-index, 1-year, 2-year, 3-year, and 5-year time-dependent AUCs were 0.628, 0.650, 0.665, 0.675, and 0.686, respectively. Conclusions The survival prediction model for resected PDAC could provide quantitative survival probabilities with reliable performance. External validation studies with other nationwide databases are needed to evaluate the performance of this model.

We developed a tool to guide decision-making for early triage of COVID-19 patients based on a predicted prognosis, using a Korean national cohort of 5,596 patients, and validated the developed tool with an external cohort of 445 patients treated in a single institution. Predictors chosen for our model were older age, male sex, subjective fever, dyspnea, altered consciousness, temperature ≥ 37.5 °C, heart rate ≥ 100 bpm, systolic blood pressure ≥ 160 mmHg, diabetes mellitus, heart disease, chronic kidney disease, cancer, dementia, anemia, leukocytosis, lymphocytopenia, and thrombocytopenia. In the external validation, when age, sex, symptoms, and underlying disease were used as predictors, the AUC used as an evaluation metric for our model’s performance was 0.850 in predicting whether a patient will require at least oxygen therapy and 0.833 in predicting whether a patient will need critical care or die from COVID-19. The AUCs improved to 0.871 and 0.864, respectively, when additional information on vital signs and blood test results were also used. In contrast, the protocols currently recommended in Korea showed AUCs less than 0.75. An application for calculating the prognostic score in COVID-19 patients based on the results of this study is presented on our website (https://nhimc.shinyapps.io/ih-psc/), where the results of the validation ongoing in our institution are periodically updated.

Background 4-hexylresorcinol (4HR) has been shown to have anti-oxidant activity similar to that of resveratrol. As resveratrol increases sirtuin (SIRT) activity, 4HR might behave similarly to resveratrol. Method In this study, the expression levels of SIRT1, SIRT3, and SIRT6 were evaluated after 4HR administration (1–100 μM). As NAD+ is a substrate for SIRTs, its levels with SIRT activity were also studied. Results In the results, SIRT3 (100 μM at 24 h) and SIRT6 (1–100 μM at 24 h and 10 μM at 8 h) were shown to have significantly higher expression levels compared to untreated control (p < 0.05). Pan-SIRT activity and the NAD+ level was significantly increased compared to that of the untreated control (p < 0.05; 10 and 100 μM at 24 h). Conclusion 4HR administration increased SIRT activity and the NAD+ level in Saos-2 cells.

Emergency data collected from sensor nodes widely distributed in wireless body sensor networks (WBSNs) are delivered to medical staff as quickly as possible, so patients’ lives can be saved through appropriate actions and treatments. However, relevant data and vital data may be required for appropriate actions by the medical staff. Therefore, all these data must be properly delivered to the medical staff within the set time. In this paper, we propose a MAC protocol with a reservation function and an operation frame extension function to extend the overall network lifetime by reducing the energy consumption of given sensor nodes and quickly deliver information to medical systems in case of emergency. This MAC protocol makes it possible to achieve fast transmission of related data by utilizing the related-priority slots. As a result of the experiment, the transmission delay was reduced by about 12.5%, and the lifetime was increased by approximately 19% over the existing MAC protocol. It also can be seen that the proposed MAC protocol works well in an environment where emergency events often occur.

Background/aims Constipation is a common gastrointestinal problem in the elderly. Because of the limitations of life style modifications and the comorbidity, laxative use is also very common. Therefore, this study reviews the latest literature on the effect and safety of laxative in the elderly. Methods A systematic review of randomized controlled trials investigating the effectiveness and safety of laxatives for constipation in elderly patients over 65 years old were performed using the following databases: PubMed, EMBASE, and the Cochrane Library. Results Twenty-three randomized controlled trials were included in this review. Among the selected studies, 9 studies compared laxative with placebo and 5 studies compared laxatives of the same type. Four studies compared different types of laxatives or compared combination agents. Five studies compared novel medications such as prucalopride, lubiprostone, and elobixibat with placebo. Psyllium, calcium polycarbophil, lactulose syrup, lactitol, polyethylene glycol, magnesium hydroxide, stimulant laxative with or without fiber, and other medications were more effective than placebo in elderly constipation patients in short-term. Generally, the frequency and severity of adverse effects of laxative were similar between the arms of studies. Conclusions Bulk laxative, osmotic laxative, stimulant laxative with or without fiber, and other medications can be used in elderly patients in short-term within 3 months with reasonable safety. However, the quality of included studies was not high and most of studies was conducted in a small number of patients. Among these laxatives, polyethylene glycol seems to be safe and effective in long-term use of about 6 months in elderly patients.

Preoperative imatinib treatment for rectal gastrointestinal stromal tumors (GISTs) has been reported to reduce the tumor size and help preserve the anal sphincter function. On the other hand, preoperative imatinib may prevent an accurate assessment of the recurrent risk. The endoscopic resection of rectal GIST is rarely reported because of challenges that include securing the visual field and avoiding perforation. This paper reports a case in which a 5.5×4.0 cm sized rectal GIST was treated effectively by an endoscopic submucosal dissection (ESD) without preoperative imatinib. To date, the patient had no tumor recurrence or complications and is receiving adjuvant imatinib treatment. This case shows that ESD may be a good treatment option to preserve the anus in rectal GIST treatment.

BACKGROUND This study aimed to evaluate the prevalence of monosymotomatic nocturnal enuresis (MSNE) with reduced bladder capacity in children with primary nocturnal enuresis (NE) and to suggest treatment outcomes. METHODS This study retrospectively evaluated 54 children (30 males, 24 females; median age: 8; range: 5-14) who were newly diagnosed with primary NE from November 2017 to October 2019. Reduced bladder capacity in MSNE was defined when a patient's maximal voided volume (MVV) from his or her voiding diary was 75% or less than estimated functional bladder capacity ([age + 1] x 30 mL) for his or her age and there were no daytime lower urinary tract symptoms (LUTS) as assessed using history taking and questionnaires. RESULTS Nineteen (35.2%) of 54 children with newly diagnosed primary NE did not report daytime LUTS. Fifteen children (27.8%) had a reduced bladder capacity and were prescribed anticholinergic or beta-3 agonist. After three months of medication, MVV significantly increased from 117.5 mL to 183.3 mL (P = 0.010), but frequency showed no significant change from 5.7 to 4.9 times a day. Improvement in enuresis occurred completely and partially in 41.7% and 25% of participants, respectively. CONCLUSIONS The prevalence of reduced bladder capacity without daytime voiding symptoms was relatively high as 27.8% in children newly diagnosed with primary NE. In primary MSNE, reduced bladder capacity should be investigated using a frequency-volume chart in addition to thorough history taking or questionnaires. Anticholinergics or beta-3 agonists for MSNE with reduced bladder capacity are effective at increasing the bladder capacity of these patients.

We developed highly efficient quantum dot light-emitting devices (QD-LEDs) by improving the charge balance with triple hole injection and transport layers consisted of MoO3/poly[N,N′-bis(4-butylphe...

To accelerate a launch mass with a low level of pressure as possible in a railgun, it is required to hold supplied current nearly constant during launch phase. We obtained the discharging conditions for required current shaping by modeling and analysis of circuit equations coupled to acceleration equation of the launch mass. The acceleration characteristics of the railgun in the conditions were analyzed by comparing experimental and theoretical results.

The diagnostic criteria proposed by the World Health Organization did not consider the discrepancy in diagnosis between lumbar spine (LS) and femoral neck (FN) and the clinical implications is unclear. Therefore, this retrospective study evaluated the probability of fracture risk in postmenopausal women with lumbar spine (LS)–femoral neck (FN) bone mineral density (BMD) discordance or not Patients included 1066 healthy postmenopausal women (median age 55.5 years) who visited our hospital for a health check-up between May 2013 and April 2017. Discordance was defined as a difference of one or two degrees between LS BMD and FN BMD. TBS was calculated from dual energy absorptiometry (DXA) images. Fracture risk was assessed using the Fracture Risk Assessment Tool (FRAX), including TBS-adjusted FRAX Seven hundred and two patients (65.9%) showed concordant LS and FN results, whereas 364 patients (34.1%) exhibited discordance. Normal BMD was found in 519 concordant patients (73.9%). Concordant patients showed significantly higher FRAX scores, including TBS-adjusted FRAX results, than discordant patients with low LS or FN. Furthermore, FRAX results in concordant osteopenia patients were similar to that of osteoporosis patients with osteopenia or a normal result at one site. FRAX and TBS-adjusted FRAX results in concordant osteopenia patients were comparable to that of discordant osteoporosis patients We concluded that patients with colncordant osteopenia in both the FN and LS should be managed in a similar way to patients with discordant osteoporosis.

Background Right-sided congenital diaphragmatic hernia (RCDH) is relatively rare compared with left-sided congenital diaphragmatic hernia (LCDH). Clinical data of RCDH, especially with respect to antenatal prediction of neonatal outcome, are lacking. The aim of this study was to report the treatment outcomes of patients with antenatally diagnosed RCDH and to evaluate the predictability of observed-to-expected lung area-to-head circumference ratio (O/E LHR) for perinatal outcomes, focused on mortality or extracorporeal membrane oxygenation (ECMO) requirement. Methods We retrospectively reviewed the medical records of newborn infants with isolated RCDH. We analyzed and compared the clinical and prenatal characteristics including the fetal lung volume, which was measured as the O/E LHR, between the survivors and the non-survivors. Results A total of 26 (66.7%) of 39 patients with isolated RCDH survived to discharge. The O/E LHR was significantly greater in survivors (64.7 ± 21.2) than in non-survivors (40.5 ± 23.4) (P =.027). It was greater in survivors without ECMO requirement (68.3 ± 15.1) than non-survivors or those with ECMO requirement (46.3 ± 19.4; P = .010). The best O/E LHR cut-off value for predicting mortality in isolated RCDH was 50. Conclusions The findings in this study suggest that O/E LHR, a well-characterized prognostic indicator in LCDH, could be applied to a fetus with antenatally diagnosed RCDH. A large cohort study is required to verify the association between O/E LHR values and the graded severity of RCDH.

Establishing a human motion reconstruction system from very few constraints imposed on the body has been an interesting and important research topic because it significantly reduces the degrees of freedom to be managed. However, it is a well-known mathematically ill-posed problem as the dimension of constraints is much lower than that of the human pose to be determined. Therefore, it is challenging to directly reconstruct the whole body joint information from very few constraints due to many possible solutions. To address this issue, we present a novel deep learning framework with an attention mechanism using large-scale motion capture (mocap) data for mapping very few user-defined constraints into the human motion as realistically as possible. Our system is built upon the attention networks for looking back further to achieve better results. Experimental results show that our network model is capable of producing more accurate results compared with previous approaches. We also conducted several experiments to test all possible combinations of the features extracted from the mocap data, and found the best feature combination to generate high-quality poses.

To perform radar-based simultaneous localization and mapping, information on a robot’s ego-motion such as its rotation angle and velocity should be considered along with radar sensor data. In this paper, we propose a method to estimate the robot’s ego-motion using only a radar sensor without any other devices. To estimate the rotation angle of a robot, we use the distribution of detected points on a two-dimensional (2D) plane. The distributions of the detected points at successive time instants are correlated with each other, and the rotation angle can be estimated based on this correlation. In addition, the moving velocity of the robot is estimated from the trend line formed by the detected points on the 2D plane. To evaluate the performance of the proposed estimation method, the information about the robot’s ego-motion received from the robot motor is compared with the information estimated from the radar sensor data. The comparison of the yaw rate obtained through each method shows that our proposed method can estimate the rotation angle of the robot within an error of 3°. In addition, the ego-velocity of the radar-equipped robot can be estimated within an error of 0.073 m/s.

PURPOSE To ascertain the pathogenesis of macular hole (MH) associated with age-related macular degeneration (AMD) and its surgical outcomes. METHODS Patients with full-thickness MH associated with AMD (higher grades than intermediate) were enrolled. The mechanism of MH formation and closure rate after vitrectomy (surgical outcome) were determined using optical coherence tomography imaging. RESULTS The mechanism of MH formation (35 eyes) associated with AMD was classified into four types: vitreomacular traction (42.9%), gradual retinal thinning caused by subretinal drusen or pigment epithelial detachment (22.9%), massive subretinal hemorrhage (20.0%), and combined (14.3%). In the 41 eyes that underwent vitrectomy, the logarithm of the minimum angle of resolution best-corrected visual acuity improved from 0.82 (0.10-2.30) preoperative to 0.69 (0.10-2.30) postoperative (P = 0.001). Successful closure of the MH was achieved in 33 eyes (80.5%) after vitrectomy. No significant association was observed between the closure rate of MH after vitrectomy and mechanism of MH formation (P = 0.083). CONCLUSION The mechanism of MH formation associated with AMD was classified into four types and was not related to its surgical outcome. Considering visual improvement and surgical outcome after vitrectomy in our study, active surgical treatment can be considered for MH associated with AMD.

BACKGROUND Little information exists regarding the incidence of chronic spontaneous urticaria (CSU) or differences in its characteristics according to age. OBJECTIVE To evaluate the incidence, clinical characteristics and treatment response of CSU according to age. METHODS The relevance of gender, age, history of allergic disease, pre-diagnosis duration, and treatment response were retrospectively evaluated in patients diagnosed with CSU at Pusan National University Hospital between 2011 and 2018. RESULTS A total of 970 patients were included in the study, consisting of 198 children and 772 adults. The CSU incidence increased during the study period in children, but not in adults. CSU was more common in adults than in children and the peak age of occurrence was 20-59 years. Increased female incidence was noted in adults, whereas patient and family allergic history was frequently observed in children than in adults. The overall rate of improvement was remarkably higher in children than in adults (P < 0.01), with pre-diagnosis duration and treatment duration both shorter in children than in adults. (P = 0.001). The proportion of men was higher and treatment duration was shorter in adolescence than in the other age groups, whereas the treatment duration was shorter in patients greater or equal to 60 years than in adults under 60 years, and the step 1 treatment rate was higher. CONCLUSION CSU incidence increased annually in children, but not in adults. The clinical characteristics and treatment response of CSU may differ depending on age and clinicians should be made aware of this fact.

PURPOSE: Single-photon emission computed tomography/computed tomography (SPECT/CT) is an advanced hybrid nuclear medicine technology that generates both functional and anatomical images in a single study. As utilization of SPECT/CT in Korea has been increasing, the purpose of this study was to survey its application of cardiac and skeletal SPECT/CT imaging for protocol optimization. METHODS: We surveyed CT protocols established for cardiac and skeletal SPECT/CT. We searched the guidelines for the CT protocols for SPECT/CT and reviewed the literature recently published. RESULTS: Among 36 hybrid SPECT scanners equipped with four or more multi-channel detector CTs (MDCTs), 18 scanners were used to perform cardiac studies at both very low current CT (30–80 mA; 11.1%) and ultra-low current CT (13–30 mA; 88.9%). Among the 33 canners, very low current (≤ 80 mA) CT or low current CT (80–130 mA) was used in 23.5%, and 41.8% for spine disorders, and in 36.4% or 30.3% for foot/ankle disorders, respectively. In the CT reconstructions, slice thickness of 5 mm for cardiac studies was most commonly used (94.4%); thinner slices (0.6–1.0 mm) for spine and foot/ankle studies were used in 24.2% and 45.5%, respectively. We also reviewed the international guidelines. CONCLUSIONS: The results and current recommendations will be helpful for optimizing CT protocols for SPECT/CT. Optimization of SPECT/CT protocols will be required for generating the proper strategy for the specific lesions and clinical purpose.

Once-daily tacrolimus reduces non-compliance relative to twice-daily tacrolimus. However, little is known about the safety and efficacy of conversion from twice-daily tacrolimus to generic once-daily tacrolimus in liver transplantation (LT). Herein, we investigated the efficacy and safety of a switch from twice-daily tacrolimus to generic once-daily tacrolimus in patients with stable liver graft function.This prospective, multicenter, open-label, single-arm study was conducted in 17 medical centers for 1 year from July 2019 to July 2020 (NCT04069065). Primary endpoint was the incidence of biopsy-proven acute rejection (BPAR) for 24 weeks after conversion. Secondary endpoints were graft failure, patient death, and adverse events (AEs).Of 151 screened LT patients, 144 patients were enrolled. BPAR, graft failure, and patient death did not occur in this patient population. There were no statistical differences in blood tests, liver function tests, or biochemical tests between visits in any of the patients. Median tacrolimus trough level decreased abruptly from 4.7 ng/mL to 3.2 ng/mL after generic once-daily tacrolimus conversion, but median tacrolimus dose increased due to low tacrolimus trough level. Ninety-two adverse events occurred in 54 patients. Liver enzyme levels increased in seven patients (4.9%) after the switch to generic once-daily tacrolimus, but the liver function tests of these patients normalized thereafter. There were three cases of severe AEs not related to investigational drug.Present study suggests that conversion from twice-daily tacrolimus to generic once-daily tacrolimus is effective and safe in stable LT patients.