Publications by authors named "Minsoo Kim"

262 Publications

Mitochondrial ATP Synthase Subunit d, a Component of the Peripheral Stalk, is Essential for Growth and Heat Stress Tolerance in Arabidopsis thaliana.

Plant J 2021 May 11. Epub 2021 May 11.

University of Massachusetts Amherst, Amherst, MA, USA, 01003.

As rapid changes in climate threaten global crop yields, an understanding of plant heat stress tolerance is increasingly relevant. Heat stress tolerance involves the coordinated action of many cellular processes and is particularly energy demanding. We acquired a knockout mutant and generated knockdown lines in Arabidopsis thaliana of the d subunit of mitochondrial ATP synthase (gene name: ATPQ, AT3G52300, referred to hereafter as ATPd), a subunit of the peripheral stalk, and used these to investigate the phenotypic significance of this subunit in normal growth and heat stress tolerance. Homozygous knockout mutants for ATPd could not be obtained due to gametophytic defects, while heterozygotes possess no visible phenotype. Therefore, we used RNAi to create knockdown plant lines for further studies. Proteomic analysis and blue native gels revealed that ATPd downregulation impairs only subunits of the mitochondrial ATP synthase (complex V). Knockdown plants were more sensitive to heat stress, had abnormal leaf morphology, and were severely slow growing compared to wild type. These results indicate that ATPd plays a crucial role in proper function of the mitochondrial ATP synthase holoenzyme, which, when reduced, leads to wide-ranging defects in energy-demanding cellular processes. In knockdown plants, more hydrogen peroxide accumulated and mitochondrial dysfunction stimulon (MDS) genes were activated. These data establish the essential structural role of ATPd and support the importance of complex V in normal plant growth, as well as provide new information about its requirement for heat stress tolerance.
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http://dx.doi.org/10.1111/tpj.15317DOI Listing
May 2021

Brain gene co-expression networks link complement signaling with convergent synaptic pathology in schizophrenia.

Nat Neurosci 2021 May 6. Epub 2021 May 6.

Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.

The most significant common variant association for schizophrenia (SCZ) reflects increased expression of the complement component 4A (C4A). Yet, it remains unclear how C4A interacts with other SCZ risk genes or whether the complement system more broadly is implicated in SCZ pathogenesis. Here, we integrate several existing, large-scale genetic and transcriptomic datasets to interrogate the functional role of the complement system and C4A in the human brain. Unexpectedly, we find no significant genetic enrichment among known complement system genes for SCZ. Conversely, brain co-expression network analyses using C4A as a seed gene reveal that genes downregulated when C4A expression increases exhibit strong and specific genetic enrichment for SCZ risk. This convergent genomic signal reflects synaptic processes, is sexually dimorphic and most prominent in frontal cortical brain regions, and is accentuated by smoking. Overall, these results indicate that synaptic pathways-rather than the complement system-are the driving force conferring SCZ risk.
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http://dx.doi.org/10.1038/s41593-021-00847-zDOI Listing
May 2021

Hyperspectral multiphoton microscopy for visualization of multiple, spectrally overlapped fluorescent labels.

Optica 2020 Nov;7(11):1587-1601

The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.

The insensitivity of multiphoton microscopy to optical scattering enables high-resolution, high-contrast imaging deep into tissue, including in live animals. Scattering does, however, severely limit the use of spectral dispersion techniques to improve spectral resolution. In practice, this limited spectral resolution together with the need for multiple excitation wavelengths to excite different fluorophores limits multiphoton microscopy to imaging a few, spectrally-distinct fluorescent labels at a time, restricting the complexity of biological processes that can be studied. Here, we demonstrate a hyperspectral multiphoton microscope that utilizes three different wavelength excitation sources together with multiplexed fluorescence emission detection using angle-tuned bandpass filters. This microscope maintains scattering insensitivity, while providing high enough spectral resolution on the emitted fluorescence and capitalizing on the wavelength-dependent nonlinear excitation of fluorescent dyes to enable clean separation of multiple, spectrally overlapping labels, . We demonstrated the utility of this instrument for spectral separation of closely-overlapped fluorophores in samples containing ten different colors of fluorescent beads, live cells expressing up to seven different fluorescent protein fusion constructs, and in multiple preparations in mouse cortex and inflamed skin with up to eight different cell types or tissue structures distinguished.
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http://dx.doi.org/10.1364/optica.389982DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8081374PMC
November 2020

Respiratory complex and tissue lineage drive recurrent mutations in tumour mtDNA.

Nat Metab 2021 04 8;3(4):558-570. Epub 2021 Apr 8.

Computational Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA.

Mitochondrial DNA (mtDNA) encodes protein subunits and translational machinery required for oxidative phosphorylation (OXPHOS). Using repurposed whole-exome sequencing data, in the present study we demonstrate that pathogenic mtDNA mutations arise in tumours at a rate comparable to those in the most common cancer driver genes. We identify OXPHOS complexes as critical determinants shaping somatic mtDNA mutation patterns across tumour lineages. Loss-of-function mutations accumulate at an elevated rate specifically in complex I and often arise at specific homopolymeric hotspots. In contrast, complex V is depleted of all non-synonymous mutations, suggesting that impairment of ATP synthesis and mitochondrial membrane potential dissipation are under negative selection. Common truncating mutations and rarer missense alleles are both associated with a pan-lineage transcriptional programme, even in cancer types where mtDNA mutations are comparatively rare. Pathogenic mutations of mtDNA are associated with substantial increases in overall survival of colorectal cancer patients, demonstrating a clear functional relationship between genotype and phenotype. The mitochondrial genome is therefore frequently and functionally disrupted across many cancers, with major implications for patient stratification, prognosis and therapeutic development.
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http://dx.doi.org/10.1038/s42255-021-00378-8DOI Listing
April 2021

Process optimization for the synthesis of ceramsites in terms of mechanical strength and phosphate adsorption capacity.

Chemosphere 2021 Mar 23;278:130239. Epub 2021 Mar 23.

Department of Civil and Environmental Engineering, University of Delaware, Newark, DE, 19716, United States. Electronic address:

Red mud (RM), an industrial waste of bauxite refinery, shows great potential in adsorptive phosphate immobilization but granulation of RM enables the ease for field application. Red-mud-based ceramsites with 12 compositions that blended Korean red mud, American red mud, ocher, and bentonite were synthesized through firing process (600-1000 °C). The porosity, bulk density, mechanical strength, mineralogical composition, and phosphate adsorption capacity of granulated RM were characterized and analyzed. The crystallization of plagioclases, nepheline and gehlenite was observed in the ceramsites with high alkali flux content, which enhanced both porosity and phosphate adsorption capacity. The characteristics of the ceramsites without phase transition were highly correlated with porosity. The mechanical strength of ceramsites was governed by crack population, describable by the Weibull distribution model, and thus the maximal tensile stress correlated negatively with porosity. Results showed that 32 wt % of KRREM and USREM treated at 1000 and 900 °C, respectively, yielded the best performing ceramites in terms of mechanical strength and phosphate adsorption capacity. Ultimately, the phosphate adsorption capacity, as affected by initial phosphate concentration, contact time, and temperature, of the optimized ceramsites was studied.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130239DOI Listing
March 2021

Natural Course of New-Onset Postoperative Atrial Fibrillation after Noncardiac Surgery.

J Am Heart Assoc 2021 Apr 19;10(7):e018548. Epub 2021 Mar 19.

From the Department of Cardiology Heart InstituteAsan Medical CenterUniversity of Ulan College of Medicine Seoul South Korea.

Background Postoperative atrial fibrillation (POAF) is common after cardiac surgery, but little is known about its incidence and natural course after noncardiac surgery. We evaluated the natural course and clinical impact of POAF and the long-term impact of anticoagulation therapy in patients without a history of atrial fibrillation (AF) undergoing noncardiac surgery. Methods and Results We retrospectively analyzed the database of Asan Medical Center (Seoul, Korea) to identify patients who developed new-onset POAF after undergoing noncardiac surgery between January 2006 and January 2016. The main outcomes were AF recurrence, thromboembolic event, and major bleeding during follow-up. Of 322 688 patients who underwent noncardiac surgery, 315 patients (mean age, 66.4 years; 64.4% male) had new-onset POAF with regular rhythm monitoring after discharge. AF recurred in 53 (16.8%) during 2 years of follow-up. Hypertension (hazard ratio, 2.12; =0.02), moderate-to-severe left atrial enlargement (hazard ratio, 2.33; =0.007) were independently associated with recurrence. Patients with recurrent AF had higher risks of thromboembolic events (11.2% versus 0.8%; <0.001) and major bleeding (26.9% versus 4.1%; <0.001) than those without recurrence. Patients with recurrent AF and without anticoagulation were especially predisposed to thromboembolic events (<0.001). Overall, anticoagulation therapy was not significantly associated with thromboembolic events (1.4% versus 2.5%, =0.95). Conclusions AF recurred in 16.8% of patients with POAF after noncardiac surgery. AF recurrence was associated with higher risks of adverse clinical outcomes. Considering the high risk of anticoagulation-related bleeding, the benefits of routine anticoagulation should be carefully weighed in this population. Active surveillance for AF recurrence is warranted.
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http://dx.doi.org/10.1161/JAHA.120.018548DOI Listing
April 2021

Self-Efficacy and Other Considerations in Performance of Risk-Reducing Behaviors during a Major Disease Outbreak.

J Health Commun 2021 Mar 17:1-9. Epub 2021 Mar 17.

Hanyang University, Ansan, South Korea.

This study uses the construct of crisis self-efficacy to examine the importance of different considerations in individuals' decisions to perform recommended safeguarding behaviors during the 2016 Zika virus outbreak. A national survey in the U.S. ( = 370) was administered using a validated crisis self-efficacy scale in late summer 2016, amidst the global crisis. Relationships between crisis self-efficacy and preparedness were assessed. Other considerations such as risk, proximity, and time/money resources required were examined for their importance in decisions to follow safeguarding protocol. Crisis self-efficacy significantly predicted evaluations of preparedness but not of perceived Zika risk. Also, advisories issued from state and federal health agencies influenced individuals' perceptions of preparedness. Results indicate public health information officers should assess publics' levels of crisis self-efficacy in strategic message design. State and federal advisories were important to individual assessments of preparedness. Further, results show the threat needs to be presented to audiences in clear, specific terms.
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http://dx.doi.org/10.1080/10810730.2020.1821131DOI Listing
March 2021

The spatio-temporal control of effector T cell migration.

Nat Rev Immunol 2021 Feb 24. Epub 2021 Feb 24.

David H. Smith Center for Vaccine Biology and Immunology, Aab Institute for Biomedical Sciences, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, USA.

Effector T cells leave the lymph nodes armed with specialized functional attributes. Their antigenic targets may be located anywhere in the body, posing the ultimate challenge: how to efficiently identify the target tissue, navigate through a complex tissue matrix and, ultimately, locate the immunological insult. Recent advances in real-time in situ imaging of effector T cell migratory behaviour have revealed a great degree of mechanistic plasticity that enables effector T cells to push and squeeze their way through inflamed tissues. This process is shaped by an array of 'stop' and 'go' guidance signals including target antigens, chemokines, integrin ligands and the mechanical cues of the inflamed microenvironment. Effector T cells must sense and interpret these competing signals to correctly position themselves to mediate their effector functions for complete and durable responses in infectious disease and malignancy. Tuning T cell migration therapeutically will require a new understanding of this complex decision-making process.
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http://dx.doi.org/10.1038/s41577-021-00507-0DOI Listing
February 2021

Metal-Ion Chelating Gel Polymer Electrolyte for Ni-Rich Layered Cathode Materials at a High Voltage and an Elevated Temperature.

ACS Appl Mater Interfaces 2021 Mar 18;13(8):9965-9974. Epub 2021 Feb 18.

School of Energy and Chemical Engineering, UNIST, Ulsan 44919, Korea.

Nickel-rich layered oxides (LiNiCoMnO; (1 - - ) ≥ 0.6), the high-energy-density cathode materials of lithium-ion batteries (LIBs), are seriously unstable at voltages higher than 4.5 V versus Li/Li and temperatures higher than 50 °C. Herein, we demonstrated that the failure mechanism of a nickel-rich layered oxide (LiNiCoMnO) behind the instability was successfully suppressed by employing cyanoethyl poly(vinyl alcohol) having pyrrolidone moieties (Pyrd-PVA-CN) as a metal-ion-chelating gel polymer electrolyte (GPE). The metal-ion-chelating GPE blocked the plating of transition-metal ions dissolved from the cathode by capturing the ions (anode protection). High-concentration metal-ion environments developed around the cathode surface by the GPE suppressed the irreversible phase transition of the cathode material from the layered structure to the rock-salt structure (cathode protection). Resultantly, the capacity retention was significantly improved at a high voltage and a high temperature. Capacity retention and coulombic efficiency of a full-cell configuration of a nickel-rich layered oxide with graphite were significantly improved in the presence of the GPE especially at a high cutoff voltage (4.4 V) and an elevated temperature (55 °C).
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http://dx.doi.org/10.1021/acsami.0c21164DOI Listing
March 2021

Drug resistance-free cytotoxic nanodrugs in composites for cancer therapy.

J Mater Chem B 2021 Apr 22;9(14):3143-3152. Epub 2021 Feb 22.

Department of Chemistry, School of Natural Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.

Drug resistance is a major cause of treatment failure for small-molecule cancer chemotherapies, despite the advances in combination therapies, drug delivery systems, epigenetic drugs, and proteolysis-targeting chimeras. Herein, we report the use of a drug resistance-free cytotoxic nanodrug as an alternative to small-molecule drugs. The present nanodrugs comprise 2 nm core gold nanoparticles (AuNPs) covered completely with multivalent hydrocarbon chains to a final diameter of ∼10 nm as single drug molecules. This hydrophobic drug-platform was delivered in composite form (∼35 nm) with block-copolymer like other small-molecular drugs. Upon uptake by cells, the nanodrugs enhanced the intracellular levels of reactive oxygen species and induced apoptosis, presumably reflecting multivalent interactions between aliphatic chains and intracellular biomolecules. No resistance to our novel nanodrug was observed following multiple treatment passages and the potential for use in cancer therapy was verified in a breast cancer patient-derived xenograft mouse model. These findings provide insight into the use of nano-scaled compounds as agents that evade drug resistance to cancer therapy.
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http://dx.doi.org/10.1039/d0tb02850aDOI Listing
April 2021

High-Performance Triboelectric Devices via Dielectric Polarization: A Review.

Nanoscale Res Lett 2021 Feb 12;16(1):35. Epub 2021 Feb 12.

School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea.

Energy harvesting devices based on the triboelectric effect have attracted great attention because of their higher output performance compared to other nanogenerators, which have been utilized in various wearable applications. Based on the working mechanism, the triboelectric performance is mainly proportional to the surface charge density of the triboelectric materials. Various approaches, such as modification of the surface functional group and dielectric composition of the triboelectric materials, have been employed to enhance the surface charge density, leading to improvements in triboelectric performances. Notably, tuning the dielectric properties of triboelectric materials can significantly increase the surface charge density because the surface charge is proportional to the relative permittivity of the triboelectric material. The relative dielectric constant is modified by dielectric polarization, such as electronic, vibrational (or atomic), orientation (or dipolar), ionic, and interfacial polarization. Therefore, such polarization represents a critical factor toward improving the dielectric constant and consequent triboelectric performance. In this review, we summarize the recent insights on the improvement of triboelectric performance via enhanced dielectric polarization.
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http://dx.doi.org/10.1186/s11671-021-03492-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7881083PMC
February 2021

Gate-tunable quantum dot formation between localized-resonant states in a few-layer MoS.

Nanotechnology 2021 May;32(19):195207

Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea.

We demonstrate a gate-tunable quantum dot (QD) located between two potential barriers defined in a few-layer MoS. Although both local gates used to tune the potential barriers have disorder-induced QDs, we observe diagonal current stripes in current resonant islands formed by the alignment of the Fermi levels of the electrodes and the energy levels of the disorder-induced QDs, as evidence of the gate-tunable QD. We demonstrate that the charging energy of the designed QD can be tuned in the range of 2-6 meV by changing the local-gate voltages in ∼1 V.
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http://dx.doi.org/10.1088/1361-6528/abe262DOI Listing
May 2021

Esophageal Thermal Injury after Catheter Ablation for Atrial Fibrillation with High-Power (50 Watts) Radiofrequency Energy.

Korean Circ J 2021 Feb;51(2):143-153

Division of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background And Objectives: Data regarding the safety of atrial fibrillation (AF) ablation using high-power (50 W) radiofrequency (RF) energy in Asian populations are limited. This study was conducted to evaluate the incidence and pattern of esophageal injury after high-power AF ablation in an Asian cohort.

Methods: We searched the prospective AF ablation registry to identify patients who underwent AF ablation with 50 W RF energy using the smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA, USA). Visitag™ (Biosense Webster) was used for lesion annotation with predefined settings of catheter stability (3 mm for 5 seconds) and minimum contact force (50% of time >5 g). All patients underwent upper gastrointestinal endoscopy at 1 or 3 days after the ablation.

Results: A total of 159 patients (mean age: 63±9 years, male: 69%, paroxysmal AF: 45.3%, persistent AF: 27.7%, long-standing persistent AF: 27.0%) were analyzed. Initially, 26 patients underwent pulmonary vein isolation with 50 W for 5 seconds at each point. The remaining 133 patients underwent prolonged RF duration (anterior 10 seconds and posterior 6 seconds). The incidence rates of esophageal erythema/erosion and superficial ulceration were 1.3% for each type of the lesion. Food stasis, a suggestive finding of gastroparesis, was observed in 25 (15.7%) patients. There were no cases of cardiac tamponade, stroke, or death.

Conclusions: In Asian patients, AF ablations using 50 W resulted in very low rates of mild esophageal complications.
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http://dx.doi.org/10.4070/kcj.2020.0323DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7853895PMC
February 2021

A prewarning sign for hearing loss by brainstem auditory evoked potentials during microvascular decompression surgery for hemifacial spasm.

Clin Neurophysiol 2021 Feb 2;132(2):358-364. Epub 2020 Dec 2.

Department of Neurosurgery, Konkuk University Medical Center, Seoul, Republic of Korea; Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea. Electronic address:

Objective: We aimed to define the prewarning sign of brainstem auditory evoked potentials (BAEPs) associated with cerebellar retraction (CR) during microvascular decompression surgery for hemifacial spasm.

Methods: A total of 241 patients with a latency prolongation of 1 ms or an amplitude decrement of 50% of wave V were analyzed. According to BAEPs before significant changes during CR, patients were classified into Groups A (latency prolongation of wave I [≥0.5 ms] without prolongation of the I-III interpeak interval [<0.5 ms]) and B (no latency prolongation of wave I [<0.5 ms] with prolongation of the I-III interpeak interval [≥0.5 ms]). BAEPs and postoperative hearing loss (HL) were compared between the two groups.

Results: Group B comprised 160 (66.4%) patients. With maximal changes in wave V, latency prolongation (≥1 ms) with amplitude decrement (≥50%) was more common in Group B (p < 0.018). At the end of the operation, wave V loss was observed in 11 patients, including 10 patients from Group B. Five patients developed postoperative HL; all were from Group B.

Conclusions: Latency prolongation of wave III during CR was associated with serious BAEPs changes and postoperative HL.

Significance: Latency prolongation of wave III is a significant prewarning sign.
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http://dx.doi.org/10.1016/j.clinph.2020.10.027DOI Listing
February 2021

Part II. What drives Korean adults to seek orthodontic treatment: Factors contributing to orthodontic treatment decisions.

Korean J Orthod 2021 Jan;51(1):3-14

Department of Orthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.

Objective: This study aimed to identify the perceptions of orthodontic treatment among Korean adults and determine the factors that drive them to seek orthodontic treatment.

Methods: A total of 2,321 adults aged 19-64 years were surveyed using an internet research system from a specialized research company. The participants were divided into the following groups based on their experience of and willingness to undergo orthodontic treatment: experience, acceptance, and non-acceptance groups. The characteristics of the participants were compared using analysis of variance with post-hoc analysis. Multinomial logistic regression analysis was performed in all three models with the non-acceptance group as a reference.

Results: In terms of demographic characteristics, age, gender, marital status, and education had significant influences on orthodontic treatment decisions in adults in the experience and acceptance groups ( < 0.001). When all the factors were analyzed, age, marital status, past dental treatment experience, regular oral examinations, demand for orthodontic treatment, optimal treatment period, health insurance coverage, information on orthodontic treatments, perceptions regarding orthodontic treatment, and psychosocial impact of dental esthetics significantly influenced orthodontic treatment decisions in adults in the experience and acceptance groups ( < 0.001).

Conclusions: These findings suggest that various factors influence orthodontic treatment decisions in adults. Individuals who seek orthodontic treatment were found to undergo more regular dental treatment and oral examination than those who did not. They also had a better perception of orthodontic treatment and more negative values for the psychosocial impact of dental esthetics.
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http://dx.doi.org/10.4041/kjod.2021.51.1.3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7837801PMC
January 2021

Highly Stretchable Sound-in-Display Electronics Based on Strain-Insensitive Metallic Nanonetworks.

Adv Sci (Weinh) 2020 Jan 23;8(1):2001647. Epub 2020 Nov 23.

School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan Metropolitan City 689-798 Republic of Korea.

The growing importance of human-machine interfaces and the rapid expansion of the internet of things (IoT) have inspired the integration of displays with sound generation systems to afford stretchable sound-in-display devices and thus establish human-to-machine connections via auditory system visualization. Herein, the synchronized generation of sound and color is demonstrated for a stretchable sound-in-display device with electrodes of strain-insensitive silver nanowires (AgNWs) and emissive layers of field-induced inorganic electroluminescent (EL) phosphors. In this device, EL phosphors embedded in a dielectric elastomer actuator (DEA) emit light under alternating-current bias, while audible sound waves are simultaneously generated via DEA actuation along with input sound signals. The electroluminescence and sound-generation performances of the fabricated device are highly robust and reliable, being insensitive to stretch-release cycling because of the presence of the AgNW stretchable electrodes. The presented principle of integrating light emission and acoustic systems in a single stretchable device can be further expanded to realize sound-in-display electronics for IoT and human-machine interface applications.
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http://dx.doi.org/10.1002/advs.202001647DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7788580PMC
January 2020

A therapeutic neutralizing antibody targeting receptor binding domain of SARS-CoV-2 spike protein.

Nat Commun 2021 01 12;12(1):288. Epub 2021 Jan 12.

College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Republic of Korea.

Vaccines and therapeutics are urgently needed for the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we screen human monoclonal antibodies (mAb) targeting the receptor binding domain (RBD) of the viral spike protein via antibody library constructed from peripheral blood mononuclear cells of a convalescent patient. The CT-P59 mAb potently neutralizes SARS-CoV-2 isolates including the D614G variant without antibody-dependent enhancement effect. Complex crystal structure of CT-P59 Fab/RBD shows that CT-P59 blocks interaction regions of RBD for angiotensin converting enzyme 2 (ACE2) receptor with an orientation that is notably different from previously reported RBD-targeting mAbs. Furthermore, therapeutic effects of CT-P59 are evaluated in three animal models (ferret, hamster, and rhesus monkey), demonstrating a substantial reduction in viral titer along with alleviation of clinical symptoms. Therefore, CT-P59 may be a promising therapeutic candidate for COVID-19.
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http://dx.doi.org/10.1038/s41467-020-20602-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7803729PMC
January 2021

Does a Custom Electronic Health Record Alert System Improve Physician Compliance With National Quality Measures for Palliative Bone Metastasis Radiotherapy?

JCO Clin Cancer Inform 2021 Jan;5:36-44

Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX.

Purpose: In an effort to promote cost-conscious, high-quality, and patient-centered care in the palliative radiation of painful bone metastases, the National Quality Forum (NQF) formed measure 1822 in 2012, which recommends the use of one of the four dose-fractionation schemes (30 Gy in 10 fractions, 24 Gy in 6 fractions, 20 Gy in 5 fractions, or 8 Gy in a single fraction). We investigated whether a custom electronic health record (EHR) alert system improved quality measure compliance among 88 physicians at a large academic center and institutional network.

Methods: In March 2018, a multiphase alert system was embedded in a custom web-based EHR. Prior to a course of palliative bone radiation, the alert system notified the user of NQF 1822 recommendations and, once prescription was completed, either affirmed compliance or advised a change in treatment schedule. Rates of compliance were evaluated before and after implementation of alert system.

Results: Of 2,399 treatment courses, 86.5% were compliant with NQF 1822 recommendations. There was no difference in rates of NQF 1822 compliance before or after implementation of the custom EHR alert (86.0% before March 2018 86.9% during and after March 2018, = .551).

Conclusion: There was no change in rates of compliance following implementation of a custom EHR alert system designed to make treatment recommendations based on national quality measure guidelines. To be of most benefit, future palliative bone metastasis decision aids should leverage peer review, target a clear practice deficiency, center upon high-quality practice guidelines, and allow flexibility to reflect the diversity of clinical scenarios.
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http://dx.doi.org/10.1200/CCI.20.00115DOI Listing
January 2021

Selection of HY7803 for Glutamic Acid Production Based on Comparative Genomic Analysis.

J Microbiol Biotechnol 2021 Feb;31(2):298-303

Department of Food and Nutrition, Dongduk Women's University, Seoul 02748, Republic of Korea.

Comparative genomic analysis was performed on eight species of lactic acid bacteria (LAB)- (.) (.) , (.) , and -to assess their glutamic acid production pathways. Glutamic acid is important for umami taste in foods. The only genes for glutamic acid production identified in the eight LAB were for conversion from glutamine in and , and from glucose via citrate in . Thus, was considered to be potentially the best of the species for glutamic acid production. By biochemical analyses, HY7803 was selected for glutamic acid production from among 17 strains. Strain HY7803 produced 83.16 pmol/μl glutamic acid from glucose, and exogenous supplementation of citrate increased this to 108.42 pmol/μl. Including glutamic acid, strain HY7803 produced more of 10 free amino acids than reference strains IL1403 and ATCC 7962 in the presence of exogenous citrate. The differences in the amino acid profiles of the strains were illuminated by principal component analysis. Our results indicate that HY7803 may be a good starter strain for glutamic acid production.
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http://dx.doi.org/10.4014/jmb.2011.11022DOI Listing
February 2021

Relation of Left Atrial Enlargement to Subsequent Thromboembolic Events in Nonvalvular Atrial Fibrillation Patients With Low to Borderline Embolic Risk.

Am J Cardiol 2021 03 5;143:67-73. Epub 2021 Jan 5.

Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

The current thromboembolic risk stratification of non-valvular atrial fibrillation (NVAF) does not include parameters from transthoracic echocardiography (TTE). We hypothesized that left atrial enlargement (LAE) on TTE could discriminate who require anticoagulation therapy among NVAF patients with low/borderline clinical embolic risk. This single-center cohort study included 6,602 patients with NVAF (median age, 56 years, 70.0% male) with a low to borderline clinical embolic risk (CHADS-VASc score: 0 to 1 in males, 1 to 2 in females). LAE was classified as mild (≥41 mm in males; ≥39 mm in females) or moderate-severe (≥47 mm in males; ≥43 mm in females). The main study outcome was thromboembolic event (ischemic stroke and systemic embolism). Mild and moderate-severe LAE was diagnosed in 26.1% and 32.9% of the cohort, respectively. The patients with moderate-severe LAE showed a higher prevalence of baseline comorbidities and valvular heart disease and had a higher incidence of thromboembolic events than patients with mild or no LAE at 2 years of follow-up (2.5% vs 1.3% vs 1.1%, respectively, p < 0.001). After multivariable adjustment, patients with moderate-severe LAE were at a higher risk of thromboembolic event (hazard ratio, 2.54; 95% CI, 1.65 to 3.90; p < 0.001) compared to those with no LAE. This result persisted in a subgroup analysis of anticoagulant-naïve patients. The rate of thromboembolic events in patients with low clinical embolic risk and moderate-severe LAE was not different to those with high clinical embolic risk without LAE. In conclusion, Moderate-severe LAE on TTE was a significant predictor of thromboembolic events in NVAF patients at low/borderline clinical embolic risk.
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http://dx.doi.org/10.1016/j.amjcard.2020.12.034DOI Listing
March 2021

Effect of Lumbar Epidural Steroid Injections on Osteoporotic Fracture and Bone Mineral Density in Elderly Women with Diabetes Mellitus.

Pain Res Manag 2020 5;2020:1538029. Epub 2020 Dec 5.

Department of Anatomic Pathology, School of Medicine, Kangwon National University, Kangwon National University Hospital, Chuncheon 24341, Republic of Korea.

The incidence of osteoporosis and diabetes mellitus (DM) is known to increase with aging. DM is associated with osteoporotic fractures and decreased bone mineral metabolism. However, no studies have compared the effects of DM on the changes in bone mineral density (BMD) and osteoporotic fracture after epidural steroid injections (ESIs). The present study aimed to analyze the relationship between ESI and BMD changes in elderly women with and without DM. The medical records of elderly women who underwent ESI were retrospectively analyzed. All patients had radiographic and BMD assessments performed before and after receiving lumbar ESIs. A total of 172 patients were divided into two groups according to the presence of DM. The duration of BMD monitoring was 16.1 and 16.8 months in the non-DM and DM groups, respectively. The mean total number of ESIs was 3.4 and 3.2, and the mean cumulative administered dose of glucocorticoids (dexamethasone) was 17 and 16 mg in the non-DM and DM groups, respectively. There were no significant differences between baseline and posttreatment BMD in the lumbar spine, total femur, and femoral neck region in either group. The incidence of osteoporotic fractures at the hip joint and thoracolumbar spine was not significantly different in both groups. ESIs could be used without concerns regarding osteoporosis and fractures in elderly women with DM if low doses of glucocorticoids are used.
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http://dx.doi.org/10.1155/2020/1538029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7735849PMC
March 2021

Binary Spiky/Spherical Nanoparticle Films with Hierarchical Micro/Nanostructures for High-Performance Flexible Pressure Sensors.

ACS Appl Mater Interfaces 2020 Dec 21;12(52):58403-58411. Epub 2020 Dec 21.

School of Energy and Chemical Engineering, Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea.

Flexible pressure sensors have been widely explored for their versatile applications in electronic skins, wearable healthcare monitoring devices, and robotics. However, fabrication of sensors with characteristics such as high sensitivity, linearity, and simple fabrication process remains a challenge. Therefore, we propose herein a highly flexible and sensitive pressure sensor based on a conductive binary spiky/spherical nanoparticle film that can be fabricated by a simple spray-coating method. The sea-urchin-shaped spiky nanoparticles are based on the core-shell structures of spherical silica nanoparticles decorated with conductive polyaniline spiky shells. The simple spray coating of binary spiky/spherical nanoparticles enables the formation of uniform conductive nanoparticle-based films with hierarchical nano/microstructures. The two differently shaped particles-based films (namely sea-urchin-shaped and spherical) when interlocked face-to-face to form a bilayer structure can be used as a highly sensitive piezoresistive pressure sensor. Our optimized pressure sensor exhibits high sensitivity (17.5 kPa) and linear responsivity over a wide pressure range (0.008-120 kPa), owing to the effects of stress concentration and gradual deformation of the hierarchical microporous structures with sharp nanoscale tips. Moreover, the sensor exhibits high durability over 6000 repeated cycles and practical applicability in wearable devices that can be used for healthcare monitoring and subtle airflow detection (1 L/min).
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http://dx.doi.org/10.1021/acsami.0c18543DOI Listing
December 2020

Determination of the Forming Limit for a ZIRLO™ Sheet with High Anisotropy.

Materials (Basel) 2020 Dec 16;13(24). Epub 2020 Dec 16.

Department of Mechanical and Automotive Engineering, Kongju National University, Cheonan 31080, Korea.

In this study, the experimental two-dimensional forming limit diagram (FLD) data for a ZIRLO™ sheet, which is used in nuclear fuel rod support grids, were converted and presented as a triaxiality failure diagram (TFD). Most previous studies assumed ZIRLO™ to be isotropic when calculating the effective stress and strain. However, for highly anisotropic materials, the anisotropy should be considered for calculations of effective stress and strain; hence, in this study, they were calculated by introducing the normal anisotropy coefficient. To obtain this parameter of the ZIRLO™ specimens, tensile tests were performed on specimens with 0°, 45°, and 90° angles with respect to the rolling direction. It was observed that the average normal anisotropy coefficient measured during the tests was 4.94, which is very high. The von Mises isotropic and Hill 48 anisotropic yield criterion were applied to the FLD data that were experimentally determined using a limit dome height test and were converted into effective stress and effective strain. When the FLD is converted to TFD, the curve will increase in the top-right direction if the -value is greater than 1, and this become more severe as the -value increases. The TFD, which was converted considering the anisotropy, is almost the same to the TFD obtained using the digital image correlation method in the tensile tests of four specimens with different stress states. If anisotropy is not considered, then the formability is normally underestimated. However, a highly accurate TFD can be obtained with the method proposed in this study.
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http://dx.doi.org/10.3390/ma13245743DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7765971PMC
December 2020

Effect of two-week continuous epidural administration of 2% lidocaine on mechanical allodynia induced by spinal nerve ligation in rats.

Anesth Pain Med (Seoul) 2020 Jul;15(3):334-343

Department of Anesthesiology and Pain Medicine, Kangwon National University Hospital, Kangwon National University School of Medicine, Chuncheon, Korea.

Background: Lidocaine is an effective against certain types of neuropathic pain. This study aimed to investigate whether timing of initiating continuous epidural infusion of lidocaine affected the glial activation and development of neuropathic pain induced by L5/6 spinal nerve ligation (SNL) in rats.

Methods: Following L5/6 SNL, rats were epidurally infused 2% lidocaine (drug infusion initiated on days 1, and 7 post SNL model establishment) or saline (saline infusion initiated on day 1 post SNL model establishment) continuously for 14 days. Mechanical allodynia of the hind paw to von Frey filament stimuli was determined prior to surgery, postoperative day 3, and once weekly after SNL model establishment. At 7 days after the infusion of saline or lidocaine ended, spinal activation of proinflammatory cytokines and astrocytes was evaluated immunohistochemically, using antibodies to interleukin-6 (IL-6) and glial fibrillary acidic protein (GFAP).

Results: Continuous epidural administration of 2% lidocaine for 14 days increased the mechanical withdrawal threshold regardless of the difference in timing of initiating lidocaine administration. Epidurally infusing 2% lidocaine inhibited nerve ligation-induced IL-6 and GFAP activation. In the 2% lidocaine infusion group, rats maintained the increased mechanical withdrawal threshold even at 7 days after the discontinuation of 2% lidocaine infusion.

Conclusions: Continuous epidural administration of 2% lidocaine inhibited the development of SNL-induced mechanical allodynia and suppressed IL-6 and GFAP activation regardless of the difference in timing of initiating lidocaine administration.
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http://dx.doi.org/10.17085/apm.20033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7713833PMC
July 2020

Characterization of rare earth elements present in coal ash by sequential extraction.

J Hazard Mater 2021 01 23;402:123760. Epub 2020 Aug 23.

Civil and Environmental Engineering, Konkuk University, 120 Neungdong-ro Gwangjin-gu, Seoul 05029, South Korea. Electronic address:

Although it has recently been reported that notable amounts of rare earth elements (REEs) are present in the residual coal ash, little is currently known regarding the association of these elements with the coal ash matrix, thereby limiting the potential for extraction of REEs from coal ash. In this study, we analyzed the binding characteristics of REEs within coal ash via sequential extraction and examined REE recovery during a coal ash recycling process. Major components of coal ash were found to be mineral oxides, mainly composed of Si, Fe, Al, and Ca, and residual carbons. Bottom and fly ashes were found to contain 185.8 mg/kg and 179.2 mg/kg of REEs, respectively. Tessier sequential extraction confirmed that 85 % of REEs are included in the residual fraction of both bottom and fly ashes. Furthermore, BCR sequential extraction revealed that 60-70 % of REEs are contained within the residual fraction, thereby indicating that REEs are strongly bound in both bottom and fly ashes and the use of very strong acids is required for the thorough extraction of REEs from coal ash. Additionally, it was found that 46.3 % of REEs can be recovered from the wastewaters produced during the process of coal ash-derived zeolite synthesis.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123760DOI Listing
January 2021

Orbital decompressive effect of endoscopic transorbital surgery for sphenoorbital meningioma.

Graefes Arch Clin Exp Ophthalmol 2021 Apr 23;259(4):1015-1024. Epub 2020 Nov 23.

Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro Kangnam-ku, Seoul, 06351, South Korea.

Purpose: This study was aimed at evaluating the orbital decompressive effect of endoscopic transorbital approach (TOA) in the management of sphenoorbital meningioma involving the orbit.

Methods: Patients treated with TOA for this tumor from December 2016 to December 2019 were included, and the data were reviewed. Pre- and postoperative clinical and imaging findings were compared with a volumetric study.

Results: Eighteen patients (two men and 16 women) were included. Lateral wall hyperostosis (13 patients), extraconal tumor infiltration (18 patients), intraconal tumor infiltration (seven patients), and superior and lateral rectus encasement (nine patients) were found. Intraconal tumor infiltration in the posterior orbit affected compressive optic neuropathy (CON) more often than other tumor manifestations. The orbital soft tissue volume decreased to 91.18% ± 8.19% compared to that in the contralateral side preoperatively. The postoperative volume increased to 113.73% ± 12.92% compared to the preoperative volume. The average values of LogMAR visual acuity and visual field index score of ten patients with CON improved from 0.80 to 0.42 and 48.9 to 65.9%, respectively. All 17 patients with proptosis showed improvement after surgery. There were no significant complications associated with the surgery. Additional treatment, including gamma knife surgery, was applied to 12 cases for the remaining tumor.

Conclusion: This minimally invasive surgical debulking procedure was successful in treating sphenoorbital meningioma without significant adverse events. Lateral orbital wall decompression and limited intraorbital tumor resection were effective for compressive orbitopathy from the tumor.
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http://dx.doi.org/10.1007/s00417-020-05008-9DOI Listing
April 2021

Inter/Intra-Atrial Dissociation in Patients With Maze Procedure and Its Clinical Implications: Pseudo-Block and Pseudo-Ventricular Tachycardia.

J Am Heart Assoc 2020 12 20;9(23):e018241. Epub 2020 Nov 20.

From the Division of Cardiology Asan Medical Center University of Ulsan College of Medicine Seoul Republic of Korea.

Background Severe conduction delay and inter/intra-atrial dissociation may occur in patients who undergo an extensive catheter ablation or a maze procedure for atrial tachyarrhythmia. We report a series of patients with inter/intra-atrial dissociation that mimicked complete atrioventricular block or ventricular tachycardia. Methods and Results We retrospectively reviewed the medical records of 7 patients who were referred for the evaluation of atrioventricular block (patients 1-6) or ventricular tachycardia (patient 7) that occurred after biatrial maze procedure and valvular surgery. During the electrophysiologic study, slow atrial or junctional escape rhythm dissociated from isolated atrial activity mimicked complete atrioventricular blocks. Intra-atrial dissociation of the right atrium or left atrium was observed. Atrioventricular nodal conduction from the nondissociated atrium to the ventricle was preserved in all patients, while the conduction from the dissociated atrium was blocked. In patient 7, the pacing of the ventricle by tracking of atrial tachycardia from the nondissociated left atrium/coronary sinus mimicked ventricular tachycardia during pacemaker interrogation. A total of 5 patients received new permanent pacemaker implantations during the index hospitalization for the surgery (n=2) or as a deferred procedure (n=3) according to the treatment for sick sinus syndrome. Conclusions Pseudo-atrioventricular block or pseudo-ventricular tachycardia may occur because of inter/intra-atrial dissociation after a maze procedure. The selection of patients for permanent pacemaker implantation should be determined based on the patient's symptoms and the status of the escape pacemaker and not on the apparent atrioventricular block. Proper diagnosis is important to avoid unnecessary implantation of a pacemaker or a defibrillator.
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http://dx.doi.org/10.1161/JAHA.120.018241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7763795PMC
December 2020

Highly Transparent, Flexible, and Self-Healable Thermoacoustic Loudspeakers.

ACS Appl Mater Interfaces 2020 Nov 15;12(47):53184-53192. Epub 2020 Nov 15.

School of Energy and Chemical Engineering, Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea.

Thermoacoustic (TA) loudspeakers have garnered significant attention in recent times as a novel film speaker that utilizes temperature oscillation to vibrate the surrounding air. Conventional film-type TA loudspeakers are known to experience problems when external environments damage their conductive networks, causing them to malfunction. Therefore, introducing self-healing polymers in TA loudspeakers could be an effective way to restore the surface damage of conductive networks. In this study, we present transparent, flexible, and self-healable TA loudspeakers based on silver nanowire (AgNW)-poly(urethane-hindered urea) (PUHU) conductive electrodes. Our self-healable AgNW/PUHU electrodes exhibit significant self-healing for repairing the surface damages that are caused due to the dynamic reconstruction of reversible bulky urea bonds in PUHU. The fabricated self-healable TA loudspeakers generate a sound pressure level of 61 dB at 10 kHz frequency (alternating current (AC) 7 V/direct current (DC) 1 V). In particular, the TA speakers are able to recover the original sound after healing the surface damages of electrodes at 95 °C and 80% relative humidity within 5 min. We believe that the technique proposed in this study provides a robust and powerful platform for the fabrication of transparent and flexible TA loudspeakers with excellent self-healing, which can be applied in flexible and wearable acoustic electronics.
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http://dx.doi.org/10.1021/acsami.0c12199DOI Listing
November 2020

Long-range ballistic transport of Brown-Zak fermions in graphene superlattices.

Nat Commun 2020 Nov 13;11(1):5756. Epub 2020 Nov 13.

Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.

In quantizing magnetic fields, graphene superlattices exhibit a complex fractal spectrum often referred to as the Hofstadter butterfly. It can be viewed as a collection of Landau levels that arise from quantization of Brown-Zak minibands recurring at rational (p/q) fractions of the magnetic flux quantum per superlattice unit cell. Here we show that, in graphene-on-boron-nitride superlattices, Brown-Zak fermions can exhibit mobilities above 10 cm V s and the mean free path exceeding several micrometers. The exceptional quality of our devices allows us to show that Brown-Zak minibands are 4q times degenerate and all the degeneracies (spin, valley and mini-valley) can be lifted by exchange interactions below 1 K. We also found negative bend resistance at 1/q fractions for electrical probes placed as far as several micrometers apart. The latter observation highlights the fact that Brown-Zak fermions are Bloch quasiparticles propagating in high fields along straight trajectories, just like electrons in zero field.
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http://dx.doi.org/10.1038/s41467-020-19604-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666116PMC
November 2020

Photoautotrophic hydrogen production of Rhodobacter sphaeroides in a microbial electrosynthesis cell.

Bioresour Technol 2021 Jan 29;320(Pt A):124333. Epub 2020 Oct 29.

School of Chemical and Biomolecular Engineering, Pusan National University, Busan 46241, Republic of Korea. Electronic address:

Conventional photoheterotrophic H production by purple sulfur bacteria requires additional organic substrates as the carbon and energy sources. This study examined the novel photoautotrophic H production of Rhodobacter sphaeroides with concomitant CO uptake in microbial electrosynthesis (MES). Under an applied potential of -0.9 V vs. Ag/AgCl to the cathode, Rhodobacter sphaeroides produced hydrogen with CO as the sole carbon source under illumination. The initial planktonic cells decreased rapidly in suspension, whereas biomass formation on the cathode surface increased gradually during MES operation. The electron and carbon flow under photoautotrophic conditions in MES were estimated. Glutamate, as the nitrogen source, enhanced hydrogen production significantly (328 mL/L/day) compared to NHCl (67 mL/L/day) during seven days of operation. The photoautotrophic condition with 6000 lx presented CO consumption and simultaneous biomass formation on the cathode electrode. MES-driven electron and proton transfer enabled the simultaneous production of hydrogen and CO uptake
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http://dx.doi.org/10.1016/j.biortech.2020.124333DOI Listing
January 2021