Design of Optimized Coded LFM Waveform for Spectrum Shared Radar System.

To meet the increasing demands for remote sensing, a number of radar systems using Linear Frequency Modulation (LFM) waveforms have been deployed, causing the problem of depleting frequency resources. To address this problem, several researchers have proposed the Spectrum Shared Radar System (SSRS) in which multiple radars share the same frequency band to transmit and receive their own signals. To mitigate the interferences caused by the signal transmission by other radars, SSRS employs orthogonal waveforms that inherit the orthogonality of the waveforms from orthogonal codes.

Low alanine aminotransferase as a risk factor for chronic obstructive pulmonary disease in males.

Alanine aminotransferase (ALT) levels reflect skeletal muscle volume and general performance, which are associated with chronic obstructive pulmonary disease (COPD) development and prognosis. This study aimed to investigate ALT levels as a risk factor for COPD development. This 13-year population-based retrospective observational cohort study included 422,452 participants for analysis.

Variable effects of underlying diseases on the prognosis of patients with COVID-19.

Underlying diseases might be risk factors for poor prognosis in patients with coronavirus disease (COVID-19); however, we still do not know whether these diseases are independent factors affecting prognosis, which type of underlying diseases are risk factors, and which type of clinical outcomes are affected. We retrospectively reviewed cohort data from 7,590 de-identified patients with COVID-19 who were diagnosed using severe acute respiratory syndrome-coronavirus-2 RNA polymerase chain reaction test up to May 15, 2020. We used linked-medical claims data provided by the Health Insurance Review and Assessment Service in South Korea.

Calculation of AeroMACS Spectrum Requirements Based on Traffic Simulator.

In this paper, we propose a methodology for calculating the necessary spectrum requirements of aeronautical mobile airport communication system (AeroMACS) to provide various airport communication services. To accurately calculate the spectrum requirement, it is necessary to evaluate the AeroMACS traffic demand of the peak time and statistical data on the packet traffic generated at the airport. Because there is no AeroMACS traffic model and real trace data, we have developed the AeroMACS traffic simulator based on the report of Single European Sky Air Traffic Management Research (SESAR).

FEF Values in Patients with Normal Lung Function Can Predict the Development of Chronic Obstructive Pulmonary Disease.

Purpose: The forced mid-expiratory flow (FEF) value is a potentially sensitive marker of obstructive peripheral airflow. We aimed to assess whether FEF can be an early predictor of chronic obstructive pulmonary disease (COPD).

Patients And Methods: Between July 1, 2007 and June 31, 2009, we identified 3624 patients who underwent a pulmonary function test (PFT) in Gangnam Severance Hospital.

Effect of asthma and asthma medication on the prognosis of patients with COVID-19.

Background: Coronavirus disease 2019 (COVID-19) has spread worldwide rapidly. However, the effects of asthma, asthma medication and asthma severity on the clinical outcomes of COVID-19 have not yet been established.

Methods: The study included 7590 de-identified patients, who were confirmed to have COVID-19 using the severe acute respiratory syndrome coronavirus 2 RNA-PCR tests conducted up to May 15, 2020; we used the linked-medical claims data provided by the Health Insurance Review and Assessment Service.

Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea.

Background: In January 2015, South Korea's government raised the cigarette tax, and the retail price of cigarettes abruptly increased by 80% compared to the previous year. This research aimed to determine the effect of this increase on smoking cessation among South Korean smokers.

Methods: We analyzed data collected by the 2013-2015 South Korea National Health and Nutrition Examination Survey of 15,203 South Koreans over 19 years old using regression analysis.

Colistin monotherapy versus colistin/rifampicin combination therapy in pneumonia caused by colistin-resistant Acinetobacter baumannii: A randomised controlled trial.

Objectives: The aim of this study was to confirm the synergistic effect of colistin/rifampicin combination therapy compared with colistin monotherapy in pneumonia caused by colistin-resistant Acinetobacter baumannii (CoRAB). The utility of the Etest was also assessed.

Methods: Nine subjects with pneumonia caused by CoRAB were enrolled from 20 July 2016 to 21 June 2018.

High versus low attenuation thresholds to determine the solid component of ground-glass opacity nodules.

Objectives: To evaluate and compare the diagnostic accuracy of high versus low attenuation thresholds for determining the solid component of ground-glass opacity nodules (GGNs) for the differential diagnosis of adenocarcinoma in situ (AIS) from minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA).

Methods: Eighty-six pathologically confirmed GGNs < 3 cm observed in 86 patients (27 male, 59 female; mean age, 59.3 ± 11.

Significant predictors of medically diagnosed chronic obstructive pulmonary disease in patients with preserved ratio impaired spirometry: a 3-year cohort study.

Background: Preserved ratio impaired spirometry (PRISm) is an incompletely understood respiratory condition. We investigated the incidence and significant predictive factors of chronic obstructive pulmonary disease (COPD) in PRISm patients.

Methods: From 11,922 subjects registered in the Korea National Health and Nutrition Examination Survey, never or light smokers, young subjects, and those already medically diagnosed with COPD (defined by ICD-10 code and prescribed medication) were excluded.

Regular follow-up visits reduce the risk for asthma exacerbation requiring admission in Korean adults with asthma.

Background: Asthma requires regular follow-up visits and sustained medication use. Although several studies have reported the importance of adherence to medication and compliance with the treatment, none to date have reported the importance of regular follow-up visits. We investigated the effects of regular clinical visits on asthma exacerbation.

Efficacy of adjuvant chemotherapy for completely resected stage IB non-small cell lung cancer: a retrospective study.

Background: Lung cancer is being increasingly detected in the early stages, highlighting the importance of lung cancer screening. However, there is no consensus on the post-operative management of stage IB non-small cell lung cancer (NSCLC). Therefore, this study aimed to identify the predictive factors for prognosis of stage IB NSCLC and determine the efficacy of adjuvant chemotherapy on recurrence and survival.

Hepatitis C virus p7 induces mitochondrial depolarization of isolated liver mitochondria.

Hepatitis C virus (HCV)‑encoded protein p7 is a viroporin that acts as an ion channel and is indispensable for HCV particle production. Although the main target of HCV p7 is the endoplasmic reticulum, it also targets mitochondria. HCV‑infected cells show mitochondrial depolarization and ATP depletion; however, the function of HCV p7 in mitochondria is not fully understood.

Effectiveness of proton pump inhibitor in unexplained chronic cough.

Background: Current guidelines recommend that patients with unexplained chronic cough undergo empirical proton pump inhibitor (PPI) treatment, but scientific evidence for this treatment is lacking. We investigated the effectiveness and appropriate dose of PPI therapy in chronic cough.

Methods: We included 27 patients with unexplained chronic cough after excluding subjects with positive response to postnasal drip medication.

History of pulmonary tuberculosis affects the severity and clinical outcomes of COPD.

Background And Objective: Although an association between pulmonary tuberculosis (TB) and chronic obstructive pulmonary disease (COPD) has been suggested, studies on the effect of TB in COPD patients have not been conducted. We aimed to investigate the severity and clinical outcomes of COPD in patients with and without a history of TB.

Methods: We retrospectively reviewed the data of 1784 patients with COPD in the Korean COPD Subtype Study cohort collected from December 2011 to January 2017 and followed up for 3 years.

Differences of lung microbiome in patients with clinically stable and exacerbated bronchiectasis.

Background: Molecular-based diagnostic techniques can compensate for the inherent limitations of culture-based microbiology and provide a more comprehensive description of an entire community of bacteria at a particular anatomical site. Using culture-independent DNA-based molecular techniques, the aim of the present study was to characterize, differentiate, and compare the composition of lower airway bacterial microbiome between clinically stable and acutely infected patients with bronchiectasis experiencing exacerbation.

Methods: Patients with clinically stable bronchiectasis and those experiencing acutely exacerbated bronchiectasis were recruited.

The repeatability of computed tomography lung volume measurements: Comparisons in healthy subjects, patients with obstructive lung disease, and patients with restrictive lung disease.

In this study, we examined the repeatability of computed tomography (CT) lung volume measurements in healthy individuals and patients with obstructive and restrictive lung diseases. To do this, we retrospectively enrolled 200 healthy individuals (group 1), 100 patients with obstructive lung disease (group 2), and 100 patients with restrictive lung disease (group 3) who underwent two consecutive chest CT scans within a 1-year period. The CT lung volume was measured using a threshold-based, three-dimensional auto-segmentation technique at a default range from -200 to -1024 HU.

Asthma-COPD Overlap Shows Favorable Clinical Outcomes Compared to Pure COPD in a Korean COPD Cohort.

Purpose: Comparisons of the characteristics of chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome (ACOS) have been the focus of several studies since the diseases were defined by the Global Initiative for Asthma and Global Initiative for Chronic Obstructive Lung Disease guidelines. However, no consensus is available yet. In this study, we aimed to compare the characteristics of asthma-COPD overlap (ACO) and COPD.

Sarcopenia correlates with systemic inflammation in COPD.

Background: Muscle wasting and chronic inflammation are predominant features of patients with COPD. Systemic inflammation is associated with an accelerated decline in lung function. In this study, the prevalence of sarcopenia and the relationships between sarcopenia and systemic inflammations in patients with stable COPD were investigated.

Birt-Hogg-Dube syndrome prospectively detected by review of chest computed tomography scans.

Purpose: Birt-Hogg-Dube syndrome (BHD) is a rare disorder caused by mutations in the gene that encodes folliculin (FLCN) and is inherited in an autosomal dominant manner. BHD is commonly accompanied by fibrofolliculomas, renal tumors, multiple pulmonary cysts, and spontaneous pneumothorax. The aim of this study was to detect BHD prospectively in patients undergoing chest computed tomography (CT) scans and to evaluate further the characteristics of BHD in Korea.

Dietary vitamin C intake protects against COPD: the Korea National Health and Nutrition Examination Survey in 2012.

Background: Vitamin C, as an antioxidant, has recently been suggested to provide protection against COPD; however, only few national cohort studies have investigated these effects. We aimed to confirm the protective effects of vitamin C against COPD in Korean patients.

Patients And Methods: We analyzed the data of 3,283 adults aged ≥40 years (representing 23,541,704 subjects) who underwent pulmonary function tests and responded to questionnaires on smoking history and vitamin C intake, with stratification variables and sampling weight designated by the Korea 2012 National Health and Nutrition Examination Survey.

Association of Specific Immunoglobulin E to Staphylococcal Enterotoxin with Airway Hyperresponsiveness in Asthma Patients.

Background: Specific immunoglobulin E (IgE) sensitization to staphylococcal enterotoxin (SE) has been recently considered to be related to allergic disease, including asthma. Despite studies on specific IgE (sIgE) to SE and its relationship to asthma diagnosis and severity, the association of sIgE to SE with airway hyperresponsiveness (AHR) remains unclear.

Methods: We enrolled 81 asthma patients admitted to the Severance Hospital in Korea from March 1, 2013, to February 28, 2015 and retrospectively reviewed the electronic medical records of the enrolled subjects.

The feasibility of CT lung volume as a surrogate marker of donor-recipient size matching in lung transplantation.

Donor-recipient size matching in lung transplantation (LTx) by computed tomography lung volume (CTvol) may be a reasonable approach because size matching is an anatomical issue. The purpose of this study is to evaluate the feasibility of CTvol as a surrogate marker of size matching in LTx by comparing CTvol and predicted total lung capacity (pTLC) to reference total lung capacity (TLC) values.From January to December 2014, data from 400 patients who underwent plethysmography, pulmonary function testing (PFT), and chest computed tomography scans were reviewed retrospectively.

A rare case of primary thymic adenocarcinoma mimicking small cell lung cancer.

Primary thymic adenocarcinoma is a very rare malignancy of the anterior mediastinum with no standardized treatment. A 36-year-old male patient presented with hoarseness over the past 3 months. A chest computed tomography (CT) scan showed an infiltrative mass to the proximal vessels and aortic arch in left upper mediastinum (4.