Publications by authors named "Yun-Woo Lee"

Article Synopsis
  • Liver transplant recipients are at a heightened risk for tuberculosis (TB), which can lead to increased mortality.
  • A study screened 857 liver transplant candidates for latent tuberculosis infection (LTBI), identifying 199 (23.2%) positive cases, with 171 initiating treatment.
  • Those treated for LTBI had no cases of active TB during follow-up, while untreated individuals had a 3.6% TB development rate, highlighting the effectiveness and safety of LTBI treatment in liver transplant patients.
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bacteremia is known to present a virulent clinical course, including multiple metastatic infections, which is not uncommon in Asia. However, there are limited data on the incidence and risk factors for ocular involvement in bacteremia. We retrospectively reviewed the medical records of all patients with bacteremia who underwent ophthalmologic examination in a tertiary center in Seoul, Korea, from February 2012 to December 2020.

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The sensitivity of the (1-3)-β-D-glucan (BDG) diagnostic test for candidemia varies in different clinical settings, and its usefulness in early diagnosis of candidemia is suboptimal. We evaluated the sensitivity of the test for early candidemia prediction. All adult patients with culture-proven candidemia who underwent a serum Goldstream Fungus (1-3)-β-D-Glucan Test within seven days prior to candidemia onset at a tertiary referral hospital between January 2017 and May 2021 were included.

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While a majority of wireless microrobots have shown multi-responsiveness to implement complex biomedical functions, their functional executions are strongly dependent on the range of stimulus inputs, which curtails their functional diversity. Furthermore, their responsive functions are coupled to each other, which results in the overlap of the task operations. Here, a 3D-printed multifunctional microrobot inspired by pollen grains with three hydrogel components is demonstrated: iron platinum (FePt) nanoparticle-embedded pentaerythritol triacrylate (PETA), poly N-isopropylacrylamide (pNIPAM), and poly N-isopropylacrylamide acrylic acid (pNIPAM-AAc) structures.

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Article Synopsis
  • The study aimed to assess the clinical impact of rifampicin resistance in Staphylococcus aureus infections, particularly in MRSA bacteraemia cases.
  • Data was collected from a South Korean hospital over 13 years, comparing outcomes between patients with rifampicin-resistant and rifampicin-susceptible MRSA infections.
  • Results indicated that while overall mortality was similar, the recurrence of infection was significantly higher in patients with rifampicin-resistant MRSA, suggesting that rifampicin resistance may influence the likelihood of infection recurrence.
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  • A study in South Korea (2014-2019) found 27 cases of severe pneumonia caused by Corynebacterium striatum, mostly affecting hospital-acquired pneumonia patients.
  • * About 70% of the cases were hospital-acquired, with over half of the patients being immunocompromised.
  • * The proportion of C. striatum infections among severe hospital-acquired pneumonia cases increased, while MRSA infections declined, highlighting C. striatum's growing role as a serious pneumonia threat.
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Article Synopsis
  • The study performed a competing risk analysis to identify factors influencing 90-day recurrence of Staphylococcus aureus bacteremia in a large cohort from South Korea.
  • Among 1,725 patients, 85 experienced recurrence, indicating a 5% rate, with significant risk factors including presence of a vascular graft, nasal MRSA carriage, and resistance to methicillin and rifampicin.
  • The findings suggest that these identified factors could help better estimate recurrence risk and improve patient management strategies.
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Recently, the realization of minimally invasive medical interventions on targeted tissues using wireless small-scale medical robots has received an increasing attention. For effective implementation, such robots should have a strong adhesion capability to biological tissues and at the same time easy controlled detachment should be possible, which has been challenging. To address such issue, a small-scale soft robot with octopus-inspired hydrogel adhesive (OHA) is proposed.

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This study is to evaluate the clinical characteristics and outcomes of Enterococcus raffinosus bacteremia in adults. We analyzed the medical records of adult patients with E. raffinosus bacteremia who were diagnosed and treated between 1997 and 2020 at a tertiary care teaching hospital in Seoul, Republic of Korea.

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Background: ST72-SCCIV, a community-associated methicillin-resistant (CA-MRSA) strain in Korea, originated in the community and has been spreading in health care settings. Herein, we describe the clinical and microbiological characteristics of patients with hospital-acquired MRSA bacteremia (MRSAB) caused by community-associated strains.

Methods: We analyzed hospital-acquired MRSAB cases caused by ST72-SCCIV using a prospective cohort of patients with SAB in a tertiary hospital in Korea from July 2008 to December 2018.

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Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has emerged as an important cause of infection. We conducted a longitudinal study to evaluate changes in clinical and microbiological characteristics as well as outcomes of sequence type (ST) 72 MRSA bacteremia. We reviewed adult patients enrolled in a prospective cohort with ST72 MRSA bacteremia from August 2008 to December 2018 at Asan Medical Center, Seoul, South Korea.

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There is limited data on persistent bacteremia (PB) caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Here, we aimed to investigate the clinical and microbiological characteristics of PB caused by the major CA-MRSA strain in Korea (ST72-SCCmecIV). All adult patients with S.

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We conducted a prospective, mobile-based survey on the self-reported adverse reactions in healthcare workers (HCWs) who received both doses of the BNT162b2 mRNA vaccine. Of the 342 HCWs who completed the two-dose vaccination, 265 (77.5%) responded to the survey at least once.

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Background: We performed a prospective survey on the adverse reactions following the first dose of two types of vaccines against coronavirus disease 2019 (COVID-19) in healthcare workers (HCWs) in South Korea.

Methods: HCWs at a tertiary referral hospital in Seoul, South Korea, received a chimpanzee adenovirus-vectored vaccine (ChAdOx1 nCoV-19) or an mRNA-based vaccine (BNT162b2) between March 5 and March 26, 2021. The HCWs were asked to report adverse reactions through a mobile self-report questionnaire for three days after vaccination.

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Background And Objectives: There are limited data in real clinical practice on the diagnostic value of a bronchoalveolar lavage (BAL) fluid galactomannan (GM) assay in patients with suspected invasive pulmonary aspergillosis (IPA) who had negative serum GM results. Thus, we investigated the diagnostic performance of a BAL GM assay in patients with negative serum GM assay results who were suspected to have IPA.

Methods: This retrospective study was performed between May 2008 and April 2019 at a tertiary-care hospital in Seoul, South Korea.

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Magnetically actuated and controlled mobile micromachines have the potential to be a key enabler for various wireless lab-on-a-chip manipulations and minimally invasive targeted therapies. However, their embodied, or physical, task execution capabilities that rely on magnetic programming and control alone can curtail their projected performance and functional diversity. Integration of stimuli-responsive materials with mobile magnetic micromachines can enhance their design toolbox, enabling independently controlled new functional capabilities to be defined.

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To reduce the manufacturing time of DOEs (Diffractive Optics Elements) and POEs (Periodical Optics Elements), a new fabrication method in direct laser lithography is proposed based on the laser ablation phenomenon and the thermochemical effect of chrome. The basic mechanism of the proposed method and experimental results are also presented. It was found that when a 3 × 3 rectangular pattern is fabricated, the proposed method can reduce the total lithographic length by approximately 33%.

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We fabricated synthetic double-crossover (DX) DNA lattices and natural salmon DNA (SDNA) thin films, doped with 3 combinations of double divalent metal ions (M)-doped groups (Co-Ni, Cu-Co, and Cu-Ni) and single combination of a triple M-doped group (Cu-Ni-Co) at various concentrations of M ([M]). We evaluated the optimum concentration of M ([M]) (the phase of M-doped DX DNA lattices changed from crystalline (up to ([M]) to amorphous (above [M])) and measured the current, absorbance, and photoluminescent characteristics of multiple M-doped SDNA thin films. Phase transitions (visualized in phase diagrams theoretically as well as experimentally) from crystalline to amorphous for double (Co-Ni, Cu-Co, and Cu-Ni) and triple (Cu-Ni-Co) dopings occurred between 0.

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We present an analytical formulation of the bipod flexure for mounting the 1-m primary mirror in a space telescope. Compliance and stiffness matrices of the bipod flexure are derived to estimate theoretical performance and to make initial design guidelines. We use finite element analysis to optimize the bipod design satisfying the application requirements.

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Freeform optics have emerged as promising components in diverse applications due to the potential for superior optical performance. There are many research fields in the area ranging from fabrication to measurement, with metrology being one of the most challenging tasks. In this paper, we describe a new variant of lateral shearing interferometer with a tunable laser source that enables 3D surface profile measurements of freeform optics with high speed, high vertical resolution, large departure, and large field-of-view.

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Article Synopsis
  • The study aimed to compare the QuantiFERON-TB Gold (QFT-Gold) test and the tuberculin skin test (TST) for diagnosing latent tuberculosis in rheumatoid arthritis patients versus healthy controls in South Korea.
  • A total of 143 participants (64 with RA and 79 healthy) underwent both tests, revealing a 75% agreement rate with poor kappa values indicating limited consistency between the two methods.
  • The findings suggest that there is a poor agreement between the QFT-Gold test and the TST results, highlighting the need for careful clinical decision-making in diagnosing latent tuberculosis infections in both RA patients and healthy individuals.
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A lateral shearing interferometer has an advantage over previous wavefront measuring interferometers since it requires no reference. Therefore the lateral shearing interferometer can be a powerful solution to measure a freeform surface. It, however, has some issues to be resolved before it can be implemented.

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A new mirror mounting technique applicable to the primary mirror in a space telescope is presented. This mounting technique replaces conventional bipod flexures with flexures having mechanical shims so that adjustments can be made to counter the effects of gravitational distortion of the mirror surface while being tested in the horizontal position. Astigmatic aberration due to the gravitational changes is effectively reduced by adjusting the shim thickness, and the relation between the astigmatism and the shim thickness is investigated.

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We report a new dual band compact oblique photography camera (LC11) that is the first to benefit from the incorporation of telecentricity. LC11 has a common front end F/6.6 telescope with 280 mm in aperture that forms its electro-optical (EO, F/7.

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