Publications by authors named "Hyun-Joong Kim"

155 Publications

Mucosal Vaccine Delivery Using Mucoadhesive Polymer Particulate Systems.

Tissue Eng Regen Med 2021 Jul 25. Epub 2021 Jul 25.

Lab. of Adhesion & Bio-Composites, Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.

Vaccination has been recently attracted as one of the most successful medical treatments of the prevalence of many infectious diseases. Mucosal vaccination has been interested in many researchers because mucosal immune responses play part in the first line of defense against pathogens. However, mucosal vaccination should find out an efficient antigen delivery system because the antigen should be protected from degradation and clearance, it should be targeted to mucosal sites, and it should stimulate mucosal and systemic immunity. Accordingly, mucoadhesive polymeric particles among the polymeric particles have gained much attention because they can protect the antigen from degradation, prolong the residence time of the antigen at the target site, and control the release of the loaded vaccine, and results in induction of mucosal and systemic immune responses. In this review, we discuss advances in the development of several kinds of mucoadhesive polymeric particles for mucosal vaccine delivery.
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http://dx.doi.org/10.1007/s13770-021-00373-wDOI Listing
July 2021

Programmable Dynamics of Exchange-Biased Domain Wall via Spin-Current-Induced Antiferromagnet Switching.

Adv Sci (Weinh) 2021 Jul 15:e2100908. Epub 2021 Jul 15.

Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno jungang-daero, Daegu, 42988, Republic of Korea.

Magnetic domain wall (DW) motion in perpendicularly magnetized materials is drawing increased attention due to the prospect of new type of information storage devices, such as racetrack memory. To augment the functionalities of DW motion-based devices, it is essential to improve controllability over the DW motion. Other than electric current, which is known to induce unidirectional shifting of a train of DWs, an application of in-plane magnetic field also enables the control of DW dynamics by rotating the DW magnetization and consequently modulating the inherited chiral DW structure. Applying an external bias field, however, is not a viable approach for the miniaturization of the devices as the external field acts globally. Here, the programmable exchange-coupled DW motion in the antiferromagnet (AFM)/ferromagnet (FM) system is demonstrated, where the role of an external in-plane field is replaced by the exchange bias field from AFM layer, enabling the external field-free modulations of DW motions. Interestingly, the direction of the exchange bias field can also be reconfigured by simply injecting spin currents through the device, enabling electrical and programmable operations of the device. Furthermore, the result inspires a prototype DW motion-based device based on the AFM/FM heterostructure, that could be easily integrated in logic devices.
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http://dx.doi.org/10.1002/advs.202100908DOI Listing
July 2021

Association between polyvascular disease and clinical outcomes in patients with cardiogenic shock: Results from the RESCUE registry.

Int J Cardiol 2021 Jul 8. Epub 2021 Jul 8.

Division of Cardiology, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.

Background: Clinical implications of systemic atherosclerosis in patients with cardiogenic shock (CS) remain unclear. This study investigated the association between polyvascular disease (PVD) and clinical outcome in CS patients.

Methods: A total of 1247 CS patients was enrolled from the RESCUE registry, a multicenter, observational cohort between January 2014 and December 2018. They were divided into two groups according to presence of PVD, defined as ≥2 coexistence of coronary artery disease, peripheral arterial disease, or cerebrovascular disease. Primary outcome was all-cause death during 12 months of follow-up.

Results: 136 (10.9%) patients were diagnosed with PVD. The risk of 12-month all-cause death was significantly higher in the PVD group than in the non-PVD group (54.4% versus 40.4%, adjusted hazard ratio [HR] 1.31, 95% confidence interval [CI] 1.02-1.69, p = 0.034). There was a significant interaction between PVD and vasoactive inotropic score (VIS) (p for interaction = 0.014). Among the 945 patients with VIS <84, PVD was associated with a higher risk of 12-month all-cause death (unadjusted HR 1.77, 95% CI 1.30-2.41, p = 0.030); among the 302 patients with VIS ≥84, the incidence of 12-month all-cause death was similar between the PVD and non-PVD groups (unadjusted HR 1.03, 95% CI 0.68-1.56, p = 0.301).

Conclusions: Presence of PVD was associated with 12-month all-cause mortality in patients with CS, especially for less severe forms of CS patients with VIS <84. Clinicaltrials.govnumber:NCT02985008.
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http://dx.doi.org/10.1016/j.ijcard.2021.07.008DOI Listing
July 2021

Comparison of in-hospital outcomes of patients with vs. without ischaemic cardiomyopathy undergoing veno-arterial-extracorporeal membrane oxygenation.

ESC Heart Fail 2021 Jun 18. Epub 2021 Jun 18.

Division of Cardiology, Department of Internal Medicine, Chungnam National University Hospital, 282 Munhwa-ro, Jung-gu, Daejeon, 35015, Republic of Korea.

Aims: This study aimed to investigate differences in baseline and treatment characteristics, and in-hospital mortality according to the aetiologies of cardiogenic shock in patients undergoing veno-arterial-extracorporeal membrane oxygenation (VA-ECMO).

Methods And Results: The RESCUE registry is a multicentre, observational cohort that includes 1247 patients with cardiogenic shock from 12 centres. A total of 496 patients requiring VA-ECMO were finally selected, and the study population was stratified by cardiogenic shock aetiology [ischaemic cardiomyopathy (ICM, n = 342) and non-ICM (NICM, n = 154)]. The primary outcome of interest was in-hospital mortality. Sensitivity analyses including propensity-score matching adjustments were performed. Mean age of the entire population was 61.8 ± 14.2, and 30.8% were women. There were significant differences in baseline characteristics; notable differences included the older age of patients with ICM (65.1 ± 13.7 vs. 58.2 ± 13.8, P < 0.001), preponderance of males [258 (75.4%) vs. 85 (55.2%), P < 0.001], and higher prevalence of diabetes mellitus [140 (40.9%) vs. 39 (25.3%), P = 0.001] compared with patients in the NICM aetiology group. Patients with ischaemic cardiogenic shock were more likely to have longer shock duration before VA-ECMO implantation (518.7 ± 941.4 min vs. 292.4 ± 707.8 min, P = 0.003) and were less likely to undergo distal limb perfusion than those with NICM [108 (31.6%) vs. 79 (51.3%), P < 0.001]. In-hospital mortality in the overall cohort was 52.2%; patients with ICM had a higher unadjusted risk of in-hospital mortality [203 (59.4%) vs. 56 (36.4%); unadjusted hazard ratio, 2.295; 95% confidence interval, 1.698-3.100; P < 0.001]. There were no significant differences in the primary outcome between the two aetiologies following propensity-score matching multiple adjustments (adjusted hazard ratio, 1.265; 95% confidence interval, 0.840-1.906; P = 0.260).

Conclusions: Results of the current study indicated among patients with cardiogenic shock undergoing VA-ECMO, ischaemic aetiology does not seem to impact in-hospital mortality. These findings underline that early initiation and appropriate treatment strategies of VA-ECMO for patients with ICM shock are required.
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http://dx.doi.org/10.1002/ehf2.13481DOI Listing
June 2021

Clinical Characteristics and Predictors of In-Hospital Mortality in Patients With Cardiogenic Shock: Results From the RESCUE Registry.

Circ Heart Fail 2021 Jun 15;14(6):e008141. Epub 2021 Jun 15.

Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center (J.H.Y., K.H.C., T.K.P., J.M.L., Y.B.S., J.-Y.H., S.-H.C., H.-C.G.), Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.

Background: In the current era of mechanical circulatory support, limited data are available on prognosis of cardiogenic shock (CS) caused by various diseases. We investigated the characteristics and predictors of in-hospital mortality in Korean patients with CS.

Methods: The RESCUE study (Retrospective and Prospective Observational Study to Investigate Clinical Outcomes and Efficacy of Left Ventricular Assist Device for Korean Patients With CS) is a multicenter, retrospective, and prospective registry of patients that presented with CS. Between January 2014 and December 2018, 1247 patients with CS were enrolled from 12 major centers in Korea. The primary outcome was in-hospital mortality.

Results: In-hospital mortality rate was 33.6%. The main causes of shock were ischemic heart disease (80.7%), dilated cardiomyopathy (6.1%), myocarditis (3.2%), and nonischemic ventricular arrhythmia (2.5%). Vasopressors were used in 1081 patients (86.7%). The most frequently used vasopressor was dopamine (63.4%) followed by norepinephrine (57.3%). An intraaortic balloon pump was used in 314 patients (25.2%) and extracorporeal membrane oxygenator in 496 patients (39.8%). In multivariable analysis, age ≥70years (odds ratio [OR], 2.73 [95% CI, 1.89-3.94], <0.001), body mass index <25 kg/m (OR, 1.52 [95% CI, 1.08-2.16], =0.017), cardiac arrest at presentation (OR, 2.16 [95% CI, 1.44-3.23], <0.001), vasoactive-inotrope score >80 (OR, 3.55 [95% CI, 2.54-4.95], <0.001), requiring continuous renal replacement therapy (OR, 4.14 [95% CI, 2.88-5.95], <0.001), mechanical ventilator (OR, 3.17 [95% CI, 2.16-4.63], <0.001), intraaortic balloon pump (OR, 1.55 [95% CI, 1.07-2.24], =0.020), and extracorporeal membrane oxygenator (OR, 1.85 [95% CI, 1.25-2.76], =0.002) were independent predictors for in-hospital mortality.

Conclusions: The in-hospital mortality of patients with CS remains high despite the high utilization of mechanical circulatory support. Age, low body mass index, cardiac arrest at presentation, amount of vasopressor, and advanced organ failure requiring various support devices were poor prognostic factors for in-hospital mortality. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02985008.
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http://dx.doi.org/10.1161/CIRCHEARTFAILURE.120.008141DOI Listing
June 2021

Newly Found Digital Memory Characteristics of Pyrrolidone- and Succinimide-Based Polymers.

Macromol Rapid Commun 2021 Jul 14;42(14):e2100186. Epub 2021 May 14.

Ceko Corporation, Surface Technology Institute, 519 Dunchon-daero, Jungwon-gu, Seongnam, 13216, Republic of Korea.

This study reports for the first time the excellent nonvolatile and volatile digital memory characteristics of polymers bearing 2-pyrrolidone and succinimide moieties. A series of new polymers is synthesized from poly(ethylene-alt-maleic anhydride) and four alcohol derivatives with and without 2-pyrrolidone and succinimide moieties. All polymers, including polyvinylpyrrolidone, are found to be thermally stable up to 195 °C or higher, and characterized regarding their molecular orbital energy levels, bandgap, and resistive digital memory behaviors. Excitingly, the polymers bearing either 2-pyrrolidone or succinimide moiety demonstrate p-type digital memory behaviors with high ON/OFF current ratios and long reliabilities. Nonvolatile digital memory performance is achieved over the film thickness range of 10-80 nm, whereas volatile digital memory is demonstrated over a much narrower range of film thickness. All digital memory performances can be originated from the 2-pyrrolidone and succinimide moieties possessing high affinity and stabilization power to charges via charge traps and transformations based on a hopping conduction process. Hence, these new polymers are suitable for the production of high-performance p-type nonvolatile and volatile digital memory devices. Moreover, 2-pyrrolidone and succinimide can be used as new and economical electroactive building blocks for the development of advanced digital memory materials.
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http://dx.doi.org/10.1002/marc.202100186DOI Listing
July 2021

Detection of GM Canola MS11, DP-073496-4, and MON88302 events using multiplex PCR coupled with capillary electrophoresis.

Food Sci Biotechnol 2021 Apr 13;30(4):565-570. Epub 2021 Mar 13.

Institute of Life Sciences & Resources and Department of Food Science & Biotechnology, Kyung Hee University, Yongin, 17104 Republic of Korea.

As of 2020, 11 GM canola events have been authorized as food for humans in Korea. However, there are no simultaneous multiplex detection methods for 3 GM canola events (DP-073496-4, MON88302, and MS11). Thus, we established the multiplex polymerase chain reaction (PCR) method coupled with capillary electrophoresis to detect 3 GM canola events. To verify the specificity of event-specific primers, various GM crops of 3 GM soybean events, 6 GM maize events, 2 GM cotton events and 11 GM canola events were prepared. The limit of detection of the developed multiplex PCR was approximately 0.0125% for 3 GM canola events. Certified GM canola and stacked events were analyzed to validate the developed multiplex PCR. This study focuses on establishing multiplex PCR coupled with capillary electrophoresis for newly approved GM canola events and contributes to efficient monitoring GM canola samples in Korea.
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http://dx.doi.org/10.1007/s10068-021-00882-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8050189PMC
April 2021

Fructose-Based Production of Short-Chain-Length and Medium-Chain-Length Polyhydroxyalkanoate Copolymer by Arctic sp. B14-6.

Polymers (Basel) 2021 Apr 26;13(9). Epub 2021 Apr 26.

Department of Biological Engineering, College of Engineering, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul 05029, Korea.

Arctic bacteria employ various mechanisms to survive harsh conditions, one of which is to accumulate carbon and energy inside the cell in the form of polyhydroxyalkanoate (PHA). Whole-genome sequencing of a new Arctic soil bacterium sp. B14-6 revealed two PHA-production-related gene clusters containing four PHA synthase genes (). sp. B14-6 produced poly(6% 3-hydroxybutyrate--94% 3-hydroxyalkanoate) from various carbon sources, containing short-chain-length PHA (scl-PHA) and medium-chain-length PHA (mcl-PHA) composed of various monomers analyzed by GC-MS, such as 3-hydroxybutyrate, 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, 3-hydroxydodecenoic acid, 3-hydroxydodecanoic acid, and 3-hydroxytetradecanoic acid. By optimizing the PHA production media, we achieved 34.6% PHA content using 5% fructose, and 23.7% PHA content using 5% fructose syrup. Differential scanning calorimetry of the scl--mcl PHA determined a glass transition temperature (T) of 15.3 °C, melting temperature of 112.8 °C, crystallization temperature of 86.8 °C, and 3.82% crystallinity. In addition, gel permeation chromatography revealed a number average molecular weight of 3.6 × 10, weight average molecular weight of 9.1 × 10, and polydispersity index value of 2.5. Overall, the novel sp. B14-6 produced a polymer with high medium-chain-length content, low T, and low crystallinity, indicating its potential use in medical applications.
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http://dx.doi.org/10.3390/polym13091398DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8123457PMC
April 2021

Tung Oil-Based Production of High 3-Hydroxyhexanoate-Containing Terpolymer Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate-co-3-Hydroxyhexanoate) Using Engineered .

Polymers (Basel) 2021 Mar 29;13(7). Epub 2021 Mar 29.

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Korea.

Polyhydroxyalkanoates (PHAs) are attractive new bioplastics for the replacement of plastics derived from fossil fuels. With their biodegradable properties, they have also recently been applied to the medical field. As poly(3-hydroxybutyrate) produced by wild-type has limitations with regard to its physical properties, it is advantageous to synthesize co- or terpolymers with medium-chain-length monomers. In this study, tung oil, which has antioxidant activity due to its 80% α-eleostearic acid content, was used as a carbon source and terpolymer P(53 mol% 3-hydroxybytyrate-co-2 mol% 3-hydroxyvalerate-co-45 mol% 3-hydroxyhexanoate) with a high proportion of 3-hydroxyhexanoate was produced in Re2133/pCB81. To avail the benefits of α-eleostearic acid in the tung oil-based medium, we performed partial harvesting of PHA by using a mild water wash to recover PHA and residual tung oil on the PHA film. This resulted in a film coated with residual tung oil, showing antioxidant activity. Here, we report the first application of tung oil as a substrate for PHA production, introducing a high proportion of hydroxyhexanoate monomer into the terpolymer. Additionally, the residual tung oil was used as an antioxidant coating, resulting in the production of bioactive PHA, expanding the applicability to the medical field.
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http://dx.doi.org/10.3390/polym13071084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8036412PMC
March 2021

Adsorptive removal of crude petroleum oil from water using floating pinewood biochar decorated with coconut oil-derived fatty acids.

Sci Total Environ 2021 Aug 21;781:146636. Epub 2021 Mar 21.

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea. Electronic address:

The present investigation deals with the adsorptive removal of crude petroleum oil from the water surface using coconut oil-modified pinewood biochar. Biochar generated at higher pyrolysis temperature (700 °C) revealed higher fatty acid-binding efficiency responsible for the excellent hydrophobicity of the biochar. Fatty acids composition attached to the biochar produced at 700 °C was (mg g BC) lauric acid (9.024), myristic acid (5.065), palmitic acid (2.769), capric acid (1.639), oleic acid (1.362), stearic acid (1.114), and linoleic acid (0.130). Simulation of the experimental adsorption data of pristine and modified pinewood biochar generated at 700 °C offered the best fit to pseudo-first-order kinetics (R > 0.97) and Langmuir isotherm model (R > 0.99) based on the highest regression coefficients. Consequently, the adsorption process was mainly driven by surface hydrophobic interactions including π-π electron-donor-acceptor between electron-rich (π-donor) polycyclic aromatic hydrocarbons from the crude oil and biochar (π-acceptor). A maximum adsorption capacity (Q) of 5.315 g g was achieved by modified floating biochar within 60 min. Whereas the reusability testing revealed 49.39% and 51.40% was the adsorption efficiency of pristine and modified biochar at the fifth adsorption-desorption cycle.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146636DOI Listing
August 2021

Transparent Electromagnetic Shielding Film Utilizing Imprinting-Based Micro Patterning Technology.

Polymers (Basel) 2021 Feb 27;13(5). Epub 2021 Feb 27.

R&D Center of JB Lab Corporation, Seoul 08826, Korea.

Utilization of methods involving component integration has accelerated, owing to the growth of the smart mobile industry. However, this integration leads to interference issues between the components, thereby elucidating the importance of the electromagnetic interference (EMI) shielding technology to solve such issues. EMI shielding technology has been previously implemented via the reflection or absorption of electromagnetic waves by using conductive materials. Nevertheless, to tackle the recent changes in the industry, a transparent and flexible EMI shielding technology is necessitated. In this study, a transparent and flexible EMI shielding material was fabricated by filling a conductive binder in a film comprising an intaglio pattern; this was achieved by using the ultraviolet (UV) imprinting technology to realize mass production. Subsequently, changes in the aperture ratio and shielding characteristics were analyzed according to the structure of the pattern. Based on this analysis, a square pattern was designed and a film with an intaglio pattern was developed through a UV imprinting process. Furthermore, it was confirmed that the transmittance, conductivity, and EMI shielding rate of the film were altered while changing the coating thickness of the conductive particles in the intaglio pattern. The final film prepared in this study exhibited characteristics that satisfied the required EMI shielding performance for electric and electronic applications, while achieving flexible structural stability and transparency.
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http://dx.doi.org/10.3390/polym13050738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7956853PMC
February 2021

Mechanical Characterization of Core-Shell Rubber/Epoxy Polymers for Automotive Structural Adhesives as a Function of Operating Temperature.

Polymers (Basel) 2021 Feb 27;13(5). Epub 2021 Feb 27.

Laboratory of Adhesion and Bio-Composites, Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea.

Automotive structural adhesives must show a steady toughness performance in the temperature range of -40 °C to 80 °C, considering their actual usage environments. Core-shell rubber (CSR) nanoparticles are known to enhance the toughness of epoxy systems. In this study, a CSR, pre-dispersed, diglycidyl epoxy of bisphenol A (DGEBA) mixture at 35 wt % (KDAD-7101, Kukdo Chemical, Seoul, Korea) was used as a toughener for an automotive structural epoxy adhesive system. A simple, single-component, epoxy system of DGEBA/dicyandiamide with a latent accelerator was adopted, where the CSR content of the system was controlled from 0 to 50 phr by the CSR mixture. To determine the curing conditions, we studied the curing behavior of the system by differential scanning calorimetry (DSC). Modulus variations of the cured bulk epoxies were studied using a dynamic mechanical analyzer (DMA) in the dual cantilever mode. The flexural modulus of the cured epoxies at various temperatures (-40, -10, 20, 50, and 80 °C) showed the same tendency as the DMA results, and as the flexural strength, except at 0 phr. On the other hand, the strain at break exhibited the opposite tendency to the flexural modulus. To study the adhesion behavior, we performed single-lap joint (SLJ) and impact wedge-peel (IWP) tests. As the CSR content increased, the strength of the SLJ and dynamic resistance to the cleavage of the IWP improved. In particular, the SLJ showed excellent strength at low temperatures (32.74 MPa at 50 phr @ -40 °C (i.e., an 190% improvement compared to 17.2 MPa at 0 phr @ -40 °C)), and the IWP showed excellent energy absorption at high temperatures (21.73 J at 50 phr @ 80 °C (i.e., a 976% improvement compared to 2.07 J at 0 phr @ 80 °C)). The results were discussed in relation to the changes in the properties of the bulk epoxy depending on the temperature and CSR content. The morphology of the fracture surface was also provided, which offered useful information for composition studies using the CSR/epoxy system.
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http://dx.doi.org/10.3390/polym13050734DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7956831PMC
February 2021

Differential Prognostic Implications of Vasoactive Inotropic Score for Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock According to Use of Mechanical Circulatory Support.

Crit Care Med 2021 May;49(5):770-780

Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.

Objectives: To identify whether the prognostic implications of Vasoactive Inotropic Score according to use of mechanical circulatory support differ in the treatment of acute myocardial infarction complicated by cardiogenic shock.

Design: A multicenter retrospective and prospective observational cohort study.

Setting/patient: The REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy registry includes 1,247 patients with cardiogenic shock from 12 centers in Korea. A total of 836 patients with acute myocardial infarction complicated by cardiogenic shock were finally selected, and the study population was stratified by quartiles of Vasoactive Inotropic Score (< 10, 10-30, 30-90, and > 90) for the present study.

Interventions: None.

Measurements And Main Results: Primary endpoint was in-hospital mortality and secondary endpoint was follow-up mortality. Among the study population, 326 patients (39.0%) received medical treatment alone, 218 (26.1%) received intra-aortic balloon pump, and 292 (34.9%) received extracorporeal membrane oxygenation. In-hospital mortality occurred in 305 patients (36.5%) and was significantly higher in patients with higher Vasoactive Inotropic Score (15.6%, 20.8%, 40.2%, and 67.3%, for < 10, 10-30, 30-90, and > 90; p < 0.001). Vasoactive Inotropic Score showed better ability to predict in-hospital mortality in acute myocardial infarction patients with cardiogenic shock who received medical treatment alone (area under the curve: 0.797; 95% CI, 0.728-0.865) than in those who received intra-aortic balloon pump (area under the curve, 0.704; 95% CI, 0.625-0.783) or extracorporeal membrane oxygenation (area under the curve, 0.644; 95% CI, 0.580-0.709). The best cutoff value of Vasoactive Inotropic Score for the prediction of in-hospital mortality also differed according to the use of mechanical circulatory support (16.5, 40.1, and 84.0 for medical treatment alone, intra-aortic balloon pump, and extracorporeal membrane oxygenation, respectively). There was a significant interaction between Vasoactive Inotropic Score as a continuous value and the use of mechanical circulatory support including intra-aortic balloon pump (interaction-p = 0.006) and extracorporeal membrane oxygenation (interaction-p < 0.001) for all-cause mortality during follow-up.

Conclusions: High Vasoactive Inotropic Score was associated with significantly higher in-hospital and follow-up mortality in patients with acute myocardial infarction complicated by cardiogenic shock. The predictive value of Vasoactive Inotropic Score for mortality was significantly higher in acute myocardial infarction patients with cardiogenic shock treated by medical treatment alone than in those treated by mechanical circulatory support such as intra-aortic balloon pump or extracorporeal membrane oxygenation.
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http://dx.doi.org/10.1097/CCM.0000000000004815DOI Listing
May 2021

Improvement of cadaverine production in whole cell system with baker's yeast for cofactor regeneration.

Bioprocess Biosyst Eng 2021 Apr 24;44(4):891-899. Epub 2021 Jan 24.

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, 05029, Republic of Korea.

Cadaverine, 1,5-diaminopentane, is one of the most promising chemicals for biobased-polyamide production and it has been successfully produced up to molar concentration. Pyridoxal 5'-phosphate (PLP) is a critical cofactor for inducible lysine decarboxylase (CadA) and is required up to micromolar concentration level. Previously the regeneration of PLP in cadaverine bioconversion has been studied and salvage pathway pyridoxal kinase (PdxY) was successfully introduced; however, this system also required a continuous supply of adenosine 5'-triphosphate (ATP) for PLP regeneration from pyridoxal (PL) which add in cost. Herein, to improve the process further a method of ATP regeneration was established by applying baker's yeast with jhAY strain harboring CadA and PdxY, and demonstrated that providing a moderate amount of adenosine 5'-triphosphate (ATP) with the simple addition of baker's yeast could increase cadaverine production dramatically. After optimization of reaction conditions, such as PL, adenosine 5'-diphosphate, MgCl, and phosphate buffer, we able to achieve high production (1740 mM, 87% yield) from 2 M L-lysine. Moreover, this approach could give averaged 80.4% of cadaverine yield after three times reactions with baker's yeast and jhAY strain. It is expected that baker's yeast could be applied to other reactions requiring an ATP regeneration system.
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http://dx.doi.org/10.1007/s00449-020-02497-0DOI Listing
April 2021

Visible-Light-Curable Solvent-Free Acrylic Pressure-Sensitive Adhesives via Photoredox-Mediated Radical Polymerization.

Molecules 2021 Jan 13;26(2). Epub 2021 Jan 13.

Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Korea.

Owing to their excellent properties, such as transparency, resistance to oxidation, and high adhesivity, acrylic pressure-sensitive adhesives (PSAs) are widely used. Recently, solvent-free acrylic PSAs, which are typically prepared via photopolymerization, have attracted increasing attention because of the current strict environmental regulations. UV light is commonly used as an excitation source for photopolymerization, whereas visible light, which is safer for humans, is rarely utilized. In this study, we prepared solvent-free acrylic PSAs via visible light-driven photoredox-mediated radical polymerization. Three α-haloesters were used as additives to overcome critical shortcomings, such as the previously reported low film curing rate and poor transparency observed during additive-free photocatalytic polymerization. The film curing rate was greatly increased in the presence of α-haloesters, which lowered the photocatalyst loadings and, hence, improved the film transparency. These results confirmed that our method could be widely used to prepare general-purpose solvent-free PSAs-in particular, optically clear adhesives for electronics.
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http://dx.doi.org/10.3390/molecules26020385DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7828379PMC
January 2021

Bioprospecting of exopolysaccharide from marine Sphingobium yanoikuyae BBL01: Production, characterization, and metal chelation activity.

Bioresour Technol 2021 Mar 7;324:124674. Epub 2021 Jan 7.

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, Republic of Korea; Institute for Ubiquitous Information Technology and Applications (CBRU), Konkuk University, Seoul, Republic of Korea. Electronic address:

In the present study, an exopolysaccharide (EPS)-producing bacterial strain was isolated from the Eastern Sea (Sokcho Beach) of South Korea and identified as Sphingobium yanoikuyae BBL01. Media optimization was performed using response surface design, and a yield of 2.63 ± 0.02 g/L EPS was achieved. Purified EPS produced using lactose as the main carbon source was analyzed by GC-MS and found to be composed of α-D-xylopyranose (28.6 ± 2.0%), β-D-glucopyranose (21.0 ± 1.6%), α-D-mannopyranose (18.5 ± 1.2%), β-d-mannopyranose (13.1 ± 1.4%), β-D-xylopyranose (10.2 ± 2.1%), α-d-talopyranose (5.9 ± 1.1%), and β-d-galacturonic acid (2.43 ± 0.8%). Interestingly, different carbon sources (glucose, galactose, glycerol, lactose, sucrose, and xylose) showed no effect on EPS monomer composition, with a slight change in the mass percentage of various monosaccharides. Purified EPS was stable up to 233 °C, indicating its possible suitability as a thickening and gelling agent for food-related applications. EPS also showed considerable emulsifying, flocculating, free-radical scavenging, and metal-complexion activity, suggesting various biotechnological applications.
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http://dx.doi.org/10.1016/j.biortech.2021.124674DOI Listing
March 2021

Effects of a Δ-9-fatty acid desaturase and a cyclopropane-fatty acid synthase from the novel psychrophile Pseudomonas sp. B14-6 on bacterial membrane properties.

J Ind Microbiol Biotechnol 2020 Dec 1;47(12):1045-1057. Epub 2020 Dec 1.

Department of Biological Engineering, College of Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 05029, Republic of Korea.

Psychrophilic bacteria, living at low and mild temperatures, can contribute significantly to our understanding of microbial responses to temperature, markedly occurring in the bacterial membrane. Here, a newly isolated strain, Pseudomonas sp. B14-6, was found to dynamically change its unsaturated fatty acid and cyclic fatty acid content depending on temperature which was revealed by phospholipid fatty acid (PLFA) analysis. Genome sequencing yielded the sequences of the genes Δ-9-fatty acid desaturase (desA) and cyclopropane-fatty acid-acyl-phospholipid synthase (cfa). Overexpression of desA in Escherichia coli led to an increase in the levels of unsaturated fatty acids, resulting in decreased membrane hydrophobicity and increased fluidity. Cfa proteins from different species were all found to promote bacterial growth, despite their sequence diversity. In conclusion, PLFA analysis and genome sequencing unraveled the temperature-related behavior of Pseudomonas sp. B14-6 and the functions of two membrane-related enzymes. Our results shed new light on temperature-dependent microbial behaviors and might allow to predict the consequences of global warming on microbial communities.
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http://dx.doi.org/10.1007/s10295-020-02333-0DOI Listing
December 2020

Revealing of sugar utilization systems in Halomonas sp. YLGW01 and application for poly(3-hydroxybutyrate) production with low-cost medium and easy recovery.

Int J Biol Macromol 2021 Jan 27;167:151-159. Epub 2020 Nov 27.

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul 05029, Republic of Korea. Electronic address:

Poly(3-hydroxybutyrate) (PHB) is a common polyhydroxyalkanoate (PHA) with potential as an alternative for petroleum-based plastics. Previously, we reported a new strain, Halomonas sp. YLGW01, which hyperproduces PHB with 94% yield using fructose. In this study, we examined the PHB production machinery of Halomonas sp. YLGW01 in more detail by deep-genome sequencing, which revealed a 3,453,067-bp genome with 65.1% guanine-cytosine content and 3054 genes. We found two acetyl-CoA acetyltransferases (Acetoacetyl-CoA thiolase, PhaA), one acetoacetyl-CoA reductase (PhaB), two PHB synthases (PhaC1, PhaC2), PHB depolymerase (PhaZ), and Enoyl-CoA hydratase (PhaJ) in the genome, along with two fructose kinases and fructose transporter systems, including the phosphotransferase system (PTS) and ATP-binding transport genes. We then examined the PHB production by Halomonas sp. YLGW01 using high-fructose corn syrup (HFCS) containing fructose, glucose, and sucrose in sea water medium, resulting in 7.95 ± 0.11 g/L PHB (content, 67.39 ± 0.34%). PHB was recovered from Halomonas sp. YLGW01 using different detergents; the use of Tween 20 and SDS yielded micro-sized granules with high purity. Overall, these results reveal the distribution of PHB synthetic genes and the sugar utilization system in Halomonas sp. YLGW01 and suggest a possible method for PHB recovery.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.11.163DOI Listing
January 2021

Free Volume Effect via Various Chemical Structured Monomers on Adhesion Property and Relative Permittivity in Acrylic Pressure Sensitive Adhesives.

Polymers (Basel) 2020 Nov 10;12(11). Epub 2020 Nov 10.

Samsung Display Co., Ltd., Yongin 17113, Korea.

Acrylic pressure-sensitive adhesives (PSAs) are used as fixatives between layers of a display. PSAs' function is an important factor that determines the performance of the display. Of the various display types available, the touch screen panel (TSP) of smart devices is firmly related to the relative permittivity of the elementals. Therefore, adjusting the relative permittivity of the PSA is indispensable for driving the TSP. Accordingly, selected acrylic pre-polymers were polymerized and the pre-polymer was blended and cross-linked with monomers with different chemical structure to adjust the relative permittivity. The monomers were hexametyldisiloxane (HMDS), N-vinylcaprolactam (NVC), tert-butyl acrylate (TBA), and isooctadecyl acrylate (ISTA). The gel fraction and transmittance as a function of the monomers show a similar result to the pure acrylic PSA. However, the gel fraction value decreased to about 90% and the transmittance decreased to about 85%, due to the immiscibility between nonpolar HMDS and acrylic PSA. On the other hand, the adhesion properties were improved when NVC was added because of the polarity of the nitrogen group. In addition, the relative permittivity of the PSA decreased regardless of the monomer chosen. There was, however, a difference in the optimal content of each monomer, and NVC decreased from 4 phr content to about 3.4 in reducing relative permittivity. Through the above results, it was confirmed that NVC having a nitrogen group is most advantageous in lowering adhesion properties and relative permittivity, and necessitates further research based on the findings.
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http://dx.doi.org/10.3390/polym12112633DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7698313PMC
November 2020

Clinical Significance of Low-Flow Time in Patients Undergoing Extracorporeal Cardiopulmonary Resuscitation: Results from the RESCUE Registry.

J Clin Med 2020 Nov 7;9(11). Epub 2020 Nov 7.

Division of Cardiology, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.

Limited data are available on the association between low-flow time and survival in patients with in-hospital cardiac arrest (IHCA) who undergo extracorporeal cardiopulmonary resuscitation (ECPR). We evaluated data from 183 IHCA patients who underwent ECPR as a rescue procedure. Patients were divided into two groups: patients undergoing extracorporeal membrane oxygenation as an adjunct to standard cardiopulmonary resuscitation for less than 38 min ( = 110) or for longer than 38 min ( = 73). The ECPR ≤ 38 min group had a significantly greater incidence of survival to discharge compared to the ECPR > 38 min group (40.0% versus 24.7%, = 0.032). The incidence of good neurologic outcomes at discharge tended to be greater in the ECPR ≤ 38 min group than in the ECPR > 38 min group (35.5% versus 24.7%, = 0.102). The incidences of limb ischemia ( = 0.354) and stroke ( = 0.805) were similar between the two groups, but major bleeding occurred less frequently in the ECPR ≤ 38 min group compared to the ECPR > 38 min group ( = 0.002). Low-flow time ≤ 38 min may reduce the risk of mortality and fatal neurologic damage and could be a measure of optimal management in patients with IHCA.
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http://dx.doi.org/10.3390/jcm9113588DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7695027PMC
November 2020

NaCl Concentration-Dependent Aminoglycoside Resistance of CKY01 and Identification of Related Genes.

J Microbiol Biotechnol 2021 Feb;31(2):250-258

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea.

Among various species of marine bacteria, those belonging to the genus have several promising applications and have been studied well. However, not much information has been available on their antibiotic resistance. In our efforts to learn about the antibiotic resistance of strain CKY01, which showed production of various hydrolases and growth promotion by osmolytes in previous study, we found that it exhibited resistance to multiple antibiotics including kanamycin, ampicillin, oxacillin, carbenicillin, gentamicin, apramycin, tetracycline, and spectinomycin. However, the CKY01 resistance pattern to kanamycin, gentamicin, apramycin, tetracycline, and spectinomycin differed in the presence of 10% NaCl and 1% NaCl in the culture medium. To determine the mechanism underlying this NaCl concentration-dependent antibiotic resistance, we compared four aminoglycoside resistance genes under different salt conditions while also performing time-dependent reverse transcription PCR. We found that the gene encoding aminoglycoside phosphotransferase showed increased expression under the 10% rather than 1% NaCl conditions. When these genes were overexpressed in an strain, pETDuet-1:: showed a smaller inhibition zone in the presence of kanamycin, gentamicin, and apramycin than the respective control, suggesting was involved in aminoglycoside resistance. Our results demonstrated a more direct link between NaCl and aminoglycoside resistance exhibited by the CKY01 strain.
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http://dx.doi.org/10.4014/jmb.2009.09017DOI Listing
February 2021

Application of macroalgal biomass derived biochar and bioelectrochemical system with Shewanella for the adsorptive removal and biodegradation of toxic azo dye.

Chemosphere 2021 Feb 5;264(Pt 2):128539. Epub 2020 Oct 5.

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, 05029, South Korea. Electronic address:

The present study aimed towards adsorptive removal of the toxic azo dye onto biochar derived from Eucheuma spinosum biomass. Characterization of the produced biochar was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). Eucheuma spinosum biochar (ES-BC) produced at 600 °C revealed a maximum adsorption capacity of 331.97 mg/g towards reactive red 120 dye. The adsorption data fitted best to the pseudo-second order kinetics (R > 0.99) and Langmuir isotherm (R > 0.98) models. These adsorption models signified the chemisorption mechanism with monolayer coverage of the adsorbent surface with dye molecules. Furthermore, the adsorption process was mainly governed by electrostatic interaction, ion exchange, metal complexation, and hydrogen bonding as supported by the solution pH, FTIR, XPS, and XRD investigation. Nevertheless, alone adsorption technology could not offer a complete solution for eliminating the noxious dyes. Therefore, the bioelectrochemical system (BES) equipped with previously isolated marine Shewanella marisflavi BBL25 was intended for the complete remediation of azo dye. The BES II demonstrated highest dye decolorization (97.06%) within 48 h at biocathode where the reductive cleavage of the azo bond occurred. Cyclic voltammetry (CV) studies of the BES revealed perfect redox reactions taking place where the redox mediators shuttled the electrons to the dye molecule to accelerate the dye decolorization. Besides, the GC-MS analysis revealed biotransformation of the dye into less toxic metabolites as tested using a phyto and cytogenotoxicity.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128539DOI Listing
February 2021

Increased Antibiotic Resistance of Methicillin-Resistant USA300 Δ Mutants and a Complementation Study of Δ Mutants Using Synthetic Phenol-Soluble Modulins.

J Microbiol Biotechnol 2021 Jan;31(1):115-122

Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea.

Phenol-soluble modulins (PSMs) are responsible for regulating biofilm formation, persister cell formation, expression, host cell lysis, and anti-bacterial effects. To determine the effect of deletion on methicillin-resistant , we investigated deletion mutants including Δ, Δ, and Δ;. These mutants exhibited increased β-lactam antibiotic resistance to ampicillin and oxacillin that was shown to be caused by increased Nacetylmannosamine kinase () mRNA expression, which regulates persister cell formation, leading to changes in the pattern of phospholipid fatty acids resulting in increased anteiso-C, and increased membrane hydrophobicity with the deletion of PSMs. When synthetic PSMs were applied to Δ and Δ mutants, treatment of Δ with PSMα1-4 and Δ with PSMβ1-2 restored the sensitivity to oxacillin and slightly reduced the biofilm formation. Addition of a single fragment showed that α1, α2, α3, and β2 had an inhibiting effect on biofilms in Δ; however, β1 showed an enhancing effect on biofilms in Δ. This study demonstrates a possible reason for the increased antibiotic resistance in mutants and the effect of PSMs on biofilm formation.
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http://dx.doi.org/10.4014/jmb.2007.07034DOI Listing
January 2021

Universal field-tunable terahertz emission by ultrafast photoinduced demagnetization in Fe, Ni, and Co ferromagnetic films.

Sci Rep 2020 Sep 28;10(1):15843. Epub 2020 Sep 28.

Department of Physics, Chungbuk National University, Cheongju, 28644, South Korea.

We report a universal terahertz (THz) emission behavior from simple Ni, Fe, and Co metallic ferromagnetic films, triggered by the femtosecond laser pulse and subsequent photoinduced demagnetization on an ultrafast time scale. THz emission behavior in ferromagnetic films is found to be consistent with initial magnetization states controlled by external fields, where the hysteresis of the maximal THz emission signal is observed to be well-matched with the magnetic hysteresis curve. It is experimentally demonstrated that the ultrafast THz emission by the photoinduced demagnetization is controllable in a simple way by external fields as well as pump fluences.
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http://dx.doi.org/10.1038/s41598-020-72855-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7522994PMC
September 2020

Relationship of breastfeeding duration with joint pain and knee osteoarthritis in middle-aged Korean women: a cross-sectional study using the Korea National Health and Nutrition Examination Survey.

BMC Womens Health 2020 09 24;20(1):213. Epub 2020 Sep 24.

Jaseng Spine and Joint Research Institute, Jaseng Medical Foundation, 3F JS tower, 538 Gangnam-daero, Gangnam-gu, Seoul, 06110, Republic of Korea.

Background: The effect of joint health on the quality of life of middle-aged and older women is becoming more widely recognized with the aging of the world's population. However, the association of long-term breastfeeding with joint pain and knee osteoarthritis has not been fully examined. The aim of this study was to determine the association of prior breastfeeding duration with current joint pain and knee osteoarthritis in middle-aged Korean women.

Methods: This cross-sectional study was conducted among 3454 women aged ≥50 years who underwent knee radiography and answered a questionnaire on breastfeeding and joint pain for the 5th Korea National Health and Nutrition Examination Survey (2010-2011). After adjusting for confounding sociodemographic, medical history, and obstetric and gynecologic variables, logistic regression analysis was conducted to analyze the prevalence of joint pain and knee osteoarthritis according to breastfeeding and its duration.

Results: Among the 3454 participants, 298 had not breastfed and 1042, 815, and 1299 had breastfed for 1-24, 25-48, and ≥ 49 months, respectively. Of all participants, 1731 had joint pain and 739 were diagnosed with knee osteoarthritis after radiography. Using the non-breastfeeding group as a reference, the odds ratio (OR) for joint pain among women who breastfed ≥1 month was 1.49 (95% confidence interval [CI] 1.01-2.21). As the breastfeeding duration increased, the OR of joint pain prevalence also increased (p for trend; p = 0.002). For knee osteoarthritis, the OR was 2.30 in the 25-48 months group (95% CI 1.09-4.86). The OR of knee osteoarthritis in the ≥49 months group was 2.17 (95% CI 1.01-4.64). Sensitivity analysis after selecting only participants aged ≥60 years showed that the prevalence of joint pain and knee osteoarthritis was more positively correlated with extended breastfeeding duration (joint pain, p for trend; p = 0.005) (knee osteoarthritis, p for trend; p = 0.012).

Conclusions: Long-term feeding for more than 25 months was associated with an increased prevalence of joint pain and degenerative arthritis in Korean women aged ≥50 years.
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http://dx.doi.org/10.1186/s12905-020-01078-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7517693PMC
September 2020

Comparison of efficacies of unipedicular kyphoplasty and bipedicular kyphoplasty for treatment of single-level osteoporotic vertebral compression fractures: A STROBE-compliant retrospective study.

Medicine (Baltimore) 2020 Sep;99(38):e22046

Department of Anesthesiology and Pain Medicine, Korea University Medical Center, Guro Hospital, Seoul, Republic of Korea.

Kyphoplasty (KP) is an effective method for treating osteoporotic vertebral compression fractures (OVCFs). Although the bipedicular approach is considered the main treatment approach, the unipedicular approach has also been shown to be effective. This study aimed to retrospectively compare the radiological and clinical outcomes of unipedicular and bipedicular KP in the treatment of single-level OVCFs.In total, 96 patients with single-level OVCF who received KP were divided into 2 groups: the unipedicular group, in which 28 patients underwent KP via the unipedicular approach, and the bipedicular group, in which 68 patients underwent KP via the bipedicular approach. Clinical results, radiological findings, and complications were compared between the groups. The clinical results were evaluated for up to 1 year after surgery using a numerical rating scale score. The radiological findings were compared in terms of recovery of the lowest vertebral body height at the same location on radiographs taken both 1 day and 1 year after surgery. The degrees of recovery of the kyphotic angle (KA) were simultaneously compared. The surgical time, amount of cement used, and any postoperative complications were also compared.Both groups showed significant improvements in all clinical and radiological parameters until 1 year after surgery. The unipedicular group required significantly lower amounts of cement than the bipedicular group (unipedicular: 4.4 ± 0.8 mL, bipedicular: 5.6 ± 1.0 mL, P = .00), but there were no significant differences in the clinical and radiological results for up to 1 year after surgery. There were no significant differences in leakage of intradiscal cement, appearance of adjacent vertebral compression fractures within 1 year of surgery, and surgical time.Unipedicular and bipedicular KP significantly reduced the pain experienced by patients with single-level OVCF, restored vertebral height, and corrected the KA, which remained stable for at least 1 year after treatment. Unipedicular KP required lower amounts of cement than bipedicular KP and was as effective as bipedicular KP in terms of radiological and clinical outcomes. The results of this study have level three evidence and grade B recommendation.
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http://dx.doi.org/10.1097/MD.0000000000022046DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7505346PMC
September 2020

Enhancement of pipecolic acid production by the expression of multiple lysine cyclodeaminase in the Escherichia coli whole-cell system.

Enzyme Microb Technol 2020 Oct 6;140:109643. Epub 2020 Aug 6.

Department of Biological Engineering, College of Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 05029, Republic of Korea. Electronic address:

Pipecolic acid, a non-proteinogenic amino acid, is a metabolite in lysine metabolism and a key chiral precursor in local anesthesia and macrolide antibiotics. To replace the environmentally unfriendly chemical production or preparation procedure of pipecolic acid, many biological synthetic routes have been studied for a long time. Among them, synthesis by lysine cyclodeaminase (LCD), encoded by pipA, has several advantages, including stability of enzyme activity and NAD self-regeneration. Thus, we selected this enzyme for pipecolic acid biosynthesis in a whole-cell bioconversion. To construct a robust pipecolic acid production system, we investigated important conditions including expression vector, strain, culture conditions, and other reaction parameters. The most important factor was the introduction of multiple pipA genes into the whole-cell system. As a result, we produced 724 mM pipecolic acid (72.4 % conversion), and the productivity was 0.78 g/L/h from 1 M l-lysine after 5 days. This is the highest production reported to date.
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http://dx.doi.org/10.1016/j.enzmictec.2020.109643DOI Listing
October 2020

Effects of cranial electrotherapy stimulation on preoperative anxiety and blood pressure during anesthetic induction in patients with essential hypertension.

J Int Med Res 2020 Aug;48(8):300060520939370

Department of Anesthesiology and Pain Medicine, Korea University Ansan Hospital, Korea University College of Medicine, Gyeonggi-do, Republic of Korea.

Objective: Cranial electrotherapy stimulation (CES) is a non-invasive treatment that improves symptoms such as anxiety and pain. The purpose of this study was to analyze the effect of CES pretreatment on levels of preoperative anxiety, pain, and hemodynamic responses-especially changes in blood pressure-during anesthetic induction in patients with essential hypertension.

Methods: Eighty patients undergoing general anesthesia were randomly assigned to receive either no pretreatment (control group, n = 40) or CES pretreatment (CES group, n = 40). Anxiety scores, systolic and diastolic blood pressures, mean arterial pressure, and heart rate were measured in the general ward the evening before surgery, as well as in the preoperative holding area, operating room, and after intubation. Withdrawal responses to rocuronium injection were also measured.

Results: Anxiety scores in the operating room were significantly lower in the CES group. Withdrawal responses to rocuronium injection were also significantly lower in the CES group. There were no significant differences in hemodynamic values between the two groups.

Conclusions: CES pretreatment reduces both preoperative anxiety levels and withdrawal responses to rocuronium injection. However, it does not have a significant effect on hemodynamic responses.
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http://dx.doi.org/10.1177/0300060520939370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7469723PMC
August 2020

Mesorhizobium terrae sp. nov., a novel species isolated from soil in Jangsu, Korea.

Antonie Van Leeuwenhoek 2020 Sep 20;113(9):1279-1287. Epub 2020 Jun 20.

Biological Resources Utilization Department, National Institute of Biological Resources, Incheon, 22689, Republic of Korea.

A gram-negative, white-pigmented, aerobic, rod-shaped bacterium, designated as strain NIBRBAC000500504, was isolated from soil in Jangsu, Korea. Optimal growth of this strain was observed at 25 °C, pH 7.0, and in the presence of 0% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain NIBRBAC000500504 belonged to the genus Mesorhizobium and was closely related to Mesorhizobium shangrilense LMG 24762 (98.3% sequence similarity), Mesorhizobium australicum LMG 24608 (98.2%), Mesorhizobium qingshengii LMG 26793 (98.1%), Mesorhizobium ciceri ATCC 51585 (98.0%), Mesorhizobium loti DSM 2626 (98.0%), Mesorhizobium sophorae LMG 28223 (97.9%), Mesorhizobium waitakense LMG 28227 (97.8%), and Mesorhizobium cantuariense LMG 28225 (97.8%). Next-generation sequencing analysis indicated that the genome of strain NIBRBAC000500504 comprised a circular chromosome (5,731,152 bp, G+C content: 63.26%) and a plasmid (293,638 bp, G+C content: 61.39%) with 5672 coding sequences, 50 tRNAs, and 6 rRNAs. The major respiratory isoprenoid quinone was Q10; the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine; the major fatty acids were summed feature 8 (comprising C18:1 ω7c/C18:1 ω6c), C19:0 cyclo ω8c, C16:0, and C18:1 ω7c 11-methyl; and the G+C content of the genomic DNA was 62.9 mol%. The DNA-DNA relatedness values between NIBRBAC000500504 and its closest type strains were low. On the basis of these polyphasic taxonomic data, it is proposed that strain NIBRBAC000500504 represents a novel species of the genus Mesorhizobium, with the type strain being NIBRBAC000500504 (= KCTC 72278 = JCM 33432).
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http://dx.doi.org/10.1007/s10482-020-01435-0DOI Listing
September 2020

Absolute Change in High-Sensitivity Cardiac Troponin I at Three Hours After Presentation is Useful for Diagnosing Acute Myocardial Infarction in the Emergency Department.

Ann Lab Med 2020 11 17;40(6):474-480. Epub 2020 Jun 17.

Division of Cardiology, Department of Internal Medicine, Konkuk University School of Medicine, Konkuk University Medical Center, Seoul, Korea.

Background: A rise and/or fall in cardiac troponin value with at least one value above the 99th percentile upper reference limit is essential for acute myocardial infarction (AMI) diagnosis. We evaluated the clinical usefulness of serial high-sensitivity cardiac troponin I (hs-cTnI) measurements in AMI diagnosis, in terms of the predictability of absolute and relative changes.

Methods: For this retrospective, forward observational study, we enrolled 281 patients older than 18 years who presented with chest pain at the emergency department (ED) between August 2015 and December 2016. The patients were grouped as AMI and non-AMI, and 73 (26%) were diagnosed as having AMI. Hs-cTnI (Abbott Diagnostics, Abbott Park, IL, USA) was measured at presentation and 3 hours later. We assessed the diagnostic performance of the absolute and relative changes in hs-cTnI.

Results: The cut-off values to predict AMI were 16.2 ng/L and 42.1% for the absolute and relative hs-cTnI changes, respectively. The area under the curve of hs-cTnI for AMI diagnosis was larger for absolute changes than for relative changes [0.96 (95% confidence interval [CI], 0.92-0.98) vs 0.89 (95% CI, 0.85-0.93)] (P=0.014).

Conclusions: The absolute hs-cTnI change at 3 hours after presentation was superior to the relative change, and a rise and/or fall in hs-cTnI of >16.2 ng/L at 3 hours after presentation was useful to identify AMI in patients presenting at the ED.
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http://dx.doi.org/10.3343/alm.2020.40.6.474DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7295960PMC
November 2020
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