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Abstract To overcome memory bottleneck issues in memory‐centric chip technologies, in‐memory computing has been considered an alternative route involving simultaneous data storage and computing in a memory network. In the context of spintronics, a memory‐in‐logic device based on spin‐transfer‐torque or spin‐orbit‐torque magnetoresistive random‐access memory, and a magnetic domain wall (DW) racetrack has been studied. To expand the functionalities of a conventional magnetic DW racetrack, the study devises a reprogrammable exchange‐biased DW racetrack with local engineering of the exchange bias field (HE) in continuous magnetic films without requiring a lithography process for specific patterning of the films. Furthermore, current‐driven and field‐driven DW motion along the exchange‐biased racetrack is demonstrated. Additionally, within the route of the locally different exchange‐biased racetrack, a gate function can be performed to guide or stop DW motion by locally tuning HE. The complex maze racetrack is rewritable, and multiple input channels can be controlled.

Abstract In developing an organic light-emitting diode (OLED) panel for a foldable smartphone (specifically, a color filter on encapsulation) aimed at reducing power consumption, the use of a new optically clear adhesive (OCA) that blocks UV light was crucial. However, the incorporation of a UV-blocking agent within the OCA presented a challenge, as it restricted the traditional UV-curing methods commonly used in the manufacturing process. Although a visible-light curing technique for producing UV-blocking OCA was proposed, its slow curing speed posed a barrier to commercialization. Our study introduces a highly efficient photo-initiating system (PIS) for the rapid production of UV-blocking OCAs utilizing visible light. We have carefully selected the photocatalyst (PC) to minimize electron and energy transfer to UV-blocking agents and have chosen co-initiators that allow for faster electron transfer and more rapid PC regeneration compared to previously established amine-based co-initiators. This advancement enabled a tenfold increase in the production speed of UV-blocking OCAs, while maintaining their essential protective, transparent, and flexible properties. When applied to OLED devices, this OCA demonstrated UV protection, suggesting its potential for broader application in the safeguarding of various smart devices.

Abstract The clinical impact of different polymer technologies in newer-generation drug-eluting stents (DESs) for patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) remains poorly understood. We investigated the efficacy and safety of durable polymer DESs (DP-DESs) compared with biodegradable polymer DESs (BP-DESs). A total of 620 patients who underwent percutaneous coronary intervention with newer-generation DESs for AMI complicated by CS was divided into two groups based on polymer technology: the DP-DES group (n = 374) and the BP-DES group (n = 246). The primary outcome was target vessel failure (TVF) during a 12-month follow-up, defined as a composite of cardiac death, myocardial infarction, or target vessel revascularization. Both the DP-DES and BP-DES groups exhibited low stent thrombosis rates (1.3% vs. 1.6%, p = 0.660). The risk of TVF did not significantly differ between the two groups (34.2% vs. 28.5%, hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.69–1.29, p = 0.721). This finding remained consistent after adjustment with inverse probability of treatment weighting (28.1% vs. 25.1%, HR 0.98, 95% CI 0.77–1.27, p = 0.899). In AMI patients complicated by CS, the risk of a composite of cardiac death, myocardial infarction, or target vessel revascularization was not significantly different between those treated with DP-DESs and those treated with BP-DESs. Trial registration: RESCUE registry, https://clinicaltrials.gov/ct2/show/NCT02985008 , NCT02985008.

Upcycling is an eco-friendly method that turns waste into valuable items. Elemental sulfur, a waste substance produced in large amounts (70 million tons per year), can be converted into valuable polymers using inverse vulcanization. However, the traditional method had significant limitations, such as limited consumption and weak strength. To address this problem, we newly fabricated sulfur-based pressure-sensitive adhesives (PSAs). PSAs are soft and tacky materials that should have low modulus, and they are used extensively (3.1 million tons per year). We prepared sulfur-based PSAs in four steps: polymerization, dissolution, coating/drying, and curing. In the polymerization step, castor oil and oleic acid were employed to facilitate inverse vulcanization. The resulting polymer then underwent solvent-based depolymerization to be coated in a film form. After drying and ultra-violet (UV)-induced curing, the tapes were successfully produced. Significantly, we adjusted the PSA's crosslinking density by changing the oleic acid content and UV dose. As the amount of mono-functional oleic acid decreased or the UV dose increased, the resulting PSA's crosslinking density increased. The best conditions led to PSAs with excellent adhesion performances and creep resistance, similar to commercial tapes. Moreover, the prepared PSAs exhibited self-healing properties, suggesting the feasibility of high-performance PSAs like remoldable PSAs and conductive sensors.

Adhesives with excellent adhesion and high elongation at cryogenic temperatures are necessary for fields such as aerospace, transportation, superconductors, and medicine, but have difficult requirements. This study aimed to develop a solvent-free, two-component polyurethane (PU) adhesive with excellent adhesion and high elongation, especially in ultra-low temperature conditions. we incorporated bulky polydimethylsiloxane (PDMS) diol into the hard segment of the PU adhesive to enhance flexibility and improve physical cross-linking within the adhesive matrix. The resulting PDMS-based PU adhesive showed a tensile strength of 120 MPa at −170 °C and a high elongation of approximately 4 %. It showed a lap-shear strength of up to 13 MPa at −196 °C. Additionally, the adhesive was curable at 23 °C. In this study, the cryogenic applicability of the PU adhesive was evaluated at −170 °C (103 K, liquid natural gas) and −196 °C (77 K, liquid nitrogen). Future research on the polymer adhesive materials applicable to ultra-low temperatures, such as 20 K, may be necessary if storage and transportation of liquid hydrogen become feasible.

The evaluation of bridge safety is closely related to structural stiffness, with dynamic characteristics and displacement being key indicators. Displacement is a significant factor as it is a physical phenomenon that bridge users can directly perceive. However, accurately measuring displacement generally necessitates the installation of displacement meters within the bridge substructure and conducting load tests that require traffic closure, which can be cumbersome. This paper proposes a novel method that uses wireless accelerometers to measure ambient vibration data from bridges, extracts mode shapes and natural frequencies through the time domain decomposition (TDD) technique, and estimates static displacement under specific loads using the flexibility matrix. A field test on a 442.0 m cable-stayed bridge was conducted to verify the proposed method. The estimated displacement was compared with the actual displacement measured by a laser displacement sensor, resulting in an error rate of 3.58%. Additionally, an analysis of the accuracy of displacement estimation based on the number of measurement points indicated that securing at least seven measurement points keeps the error rate within 5%. This study could be effective for evaluating the safety of bridges in environments where load testing is difficult or for bridges that require periodic dynamic characteristics and displacement analysis due to repetitive vibrations, and it is expected to be applicable to various types of bridge structures.

Limited data are available regarding the effect of metabolic syndrome on heart failure (HF) development in young individuals. Utilizing data from the Korean National Health Insurance Service, we included a total of 1,958,284 subjects in their 40s who underwent health screening between January 2009 and December 2009 in Korea. Subjects were classified into three groups: normal, pre-metabolic syndrome (Pre-MetS), and metabolic syndrome (MetS). MetS was identified in 10.58% of males and 5.21% of females. The hazard ratio for HF in subjects with MetS was 1.968 (95% CI: 1.526–2.539) for males and 2.398 (95% CI: 1.466–3.923) for females. For those with Pre-MetS, the hazard ratio was 1.607 (95% CI: 1.293–1.997) in males and 1.893 (95% CI: 1.43–2.505) in females. Additionally, acute myocardial infarction and low hemoglobin levels were identified as significant risk factors for HF in both genders. MetS approximately doubled the risk of developing HF in individuals in their 40s. Pre-MetS was also a significant risk factor for HF in this population.

The physical and mechanical properties of biopolymers can be improved by heating technologies. In this research, we improved the properties of Polyvinyl alcohol (PVA)/Uncaria gambir extract (UGE) blend films by post-heating method. After post-heating, the blend film exhibited higher resistance to UV light and improved contact angle performance, while water vapor permeability and moisture absorption decreased. The tensile strength and toughness of the PVA/UGE blend film with a post-heating duration of 40 min were 68.8 MPa and 57.7 MPa, respectively, an increase of 131 % and 127 %, compared to films without post-heating. This facile and cost-effective fabrication method, with environmentally friendly properties, can be applied to biodegradable PVA/UGE blend films to achieve desired properties for optical devices or food packaging materials.

Background: Little is known about the association between seasonal variation and prognosis in patients with CS caused by AMI. Objectives: We investigated the 12-month clinical outcomes in patients treated with percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) according to season. Methods: A total of 695 patients undergoing PCI for AMI complicated by CS was enrolled from 12 centers in South Korea. The study patients were divided into four groups according to season in which the AMI with CS occurred (spring, n = 178 vs. summer, n = 155 vs. autumn, n = 182 vs. winter, n = 180). We compared major adverse cardiovascular events (MACEs; the composite of cardiac death, myocardial infarction, re-hospitalization due to heart failure, and any revascularization) between the four groups. Results: The risk of MACE during the 12 months after CS was similar in the four groups: spring, 68 patients, vs. summer, 69, vs. autumn, 73, vs. winter, 68 (p = 0.587). Multivariate Cox-regression analysis revealed no significant difference in 12-month MACE among groups compared to the spring group after inverse probability of treatment weighting adjustment (summer, HR 1.40, 95 % CI 0.98–1.99, p = 0.062; autumn, HR 1.26, 95 % CI 0.89–1.80, p = 0.193; winter, HR 1.18, 95 % CI 0.83–1.67, p = 0.356). The similarity of MACE between the four groups was consistent across a variety of subgroups. Conclusions: After adjusting for baseline differences, seasonal variation seems not to influence the mid-term risk of 12-month MACE in patients treated with PCI for AMI complicated by CS. Condensed abstract: Data are limited regarding the association between seasonal variation and prognosis in patients with cardiogenic shock (CS) caused by AMI. This study divided patients undergoing PCI for AMI complicated by CS into four groups based on the season of occurrence and found no significant differences in 12-month MACE between the groups after adjusting for bias and confounding factors. Multivariate analysis revealed consistent MACE similarity across subgroups. The study suggests that seasonal variation has no impact on the mid-term risk of 12-month MACE in patients with CS caused by AMI, after adjusting for baseline differences. Trial registration: ClinicalTrials.gov NCT02985008RESCUE (REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy of left ventricular assist device for Korean patients with cardiogenic shock), NCT02985008, Registered December 5, 2016 - retrospectively and prospectively. Irb information: This study was approved by the institutional review board of Samsung Medical Center (Reference number: 2016-03-130).

Abstract Limited knowledge exists regarding the predictors of mortality after successful weaning of venoarterial extracorporeal membrane oxygenation (ECMO). We aimed to identify predictors of in-hospital mortality in patients with cardiogenic shock (CS) after successful weaning from ECMO. Data were obtained from a multicenter registry of CS. Successful ECMO weaning was defined as survival with minimal mean arterial pressure (> 65 mmHg) for > 24 h after ECMO removal. The primary outcome was in-hospital mortality after successful ECMO weaning. Among 1247 patients with CS, 485 received ECMO, and 262 were successfully weaned from ECMO. In-hospital mortality occurred in 48 patients (18.3%). Survivors at discharge differed significantly from non-survivors in age, cardiovascular comorbidities, cause of CS, left ventricular ejection fraction, and use of adjunctive therapy. Five independent predictors for in-hospital mortality were identified: use of continuous renal replacement therapy (odds ratio 5.429, 95% confidence interval [CI] 2.468–11.940; p

Abstract In recent years, polymer-based tissue adhesives (TAs) have been developed as an alternative to sutures to close and seal incisions or wounds owing to their ease of use, rapid application time, low cost, and minimal tissue damage. Although significant research is being conducted to develop new TAs with improved performances using different strategies, the applications of TAs are limited by several factors, such as weak adhesion strength and poor mechanical properties. Therefore, the next-generation advanced TAs with biomimetic and multifunctional properties should be developed. Herein, we review the requirements, adhesive performances, characteristics, adhesive mechanisms, applications, commercial products, and advantages and disadvantages of proteins- and synthetic polymer-based TAs. Furthermore, future perspectives in the field of TA-based research have been discussed.

Background Clinical outcome of ischemic cardiogenic shock (CS) requiring extracorporeal membrane oxygenation is highly variable, necessitating appropriate assessment of prognosis. However, a systemic predictive model estimating the mortality of refractory ischemic CS is lacking. The PRECISE (Prediction of In‐Hospital Mortality for Patients With Refractory Ischemic Cardiogenic Shock Requiring Veno‐Arterial Extracorporeal Membrane Oxygenation Support) score was developed to predict the prognosis of refractory ischemic CS due to acute myocardial infarction. Methods and Results Data were obtained from the multicenter CS registry RESCUE (Retrospective and Prospective Observational Study to Investigate Clinical Outcomes and Efficacy of Left Ventricular Assist Device for Korean Patients With Cardiogenic Shock) that consists of 322 patients with acute myocardial infarction complicated by refractory ischemic CS requiring extracorporeal membrane oxygenation support. Fifteen parameters were selected to assess in‐hospital mortality. The developed model was validated internally and externally using an independent external cohort (n=138). Among 322 patients, 138 (42.9%) survived postdischarge. Fifteen predictors were included for model development: age, diastolic blood pressure, hypertension, chronic kidney disease, peak lactic acid, serum creatinine, lowest left ventricular ejection fraction, vasoactive inotropic score, shock to extracorporeal membrane oxygenation insertion time, extracorporeal cardiopulmonary resuscitation, use of intra‐aortic balloon pump, continuous renal replacement therapy, mechanical ventilator, successful coronary revascularization, and staged percutaneous coronary intervention. The PRECISE score yielded a high area under the receiver‐operating characteristic curve (0.894 [95% CI, 0.860–0.927]). External validation and calibration resulted in competent sensitivity (area under the receiver‐operating characteristic curve, 0.895 [95% CI, 0.853–0.930]). Conclusions The PRECISE score demonstrated high predictive performance and directly translates into the expected in‐hospital mortality rate. The PRECISE score may be used to support clinical decision‐making in ischemic CS (www.theprecisescore.com). Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02985008.

Non-collinear spin structures can exhibit unusual magnetic properties that cannot be expected in an ordinary collinear ferromagnet (FM) due to the chiral alignment of magnetic moments, offering new opportunities for applications in the field of spintronics. In the present study, we demonstrate that exchange bias pinning can be applied to a single FM layer in two different directions simultaneously, resulting in modified magnetic behaviors due to the formation of non-collinear helical spin structures in the multilayers of Co0.7Ni0.3O (antiferromagnet, AFM)/Co0.7Ni0.3 (FM)/Co0.7Ni0.3O (AFM)/Pt (heavy metal, HM). The pinning of spins at one interface between FM and AFM/HM was controlled by spin Hall current originating from the electrical current through the HM layer at room temperature, while the spins at the other interface between FM and AFM were pinned in a fixed direction, hence allowing for the formation of a helical spin structure along the FM layer thickness with controllable chirality at room temperature. Modified magnetic behaviors of a helical spin structure were confirmed from measurements of magnetic hysteresis and magnetoresistance, as well as direct observation of magnetic domains.

In this study, we synthesized a gallol-functionalized PSA and generated micropatterns on its surface to improve its underwater adhesion. Compared to the adhesive-substrate interactions of benzyl and phenol-functionalized PSAs in water, Gallol PSA exhibited greater interactions with the substrate. Furthermore, the micropattern on the PSA surface provided a drainage channel for water during the bonding process so that water is not trapped at the substrate-adhesive interface. Moreover, the drainage channel allows the formation of small and uniform adhesion defects, which minimize the deterioration in adhesion caused by water. And the adhesive manufacturing process is also simple, without any gallol protection and deprotection steps, and can be achieved using the current adhesive industry infrastructure. This facile fabrication strategy and its adhesive properties could promote the commercialization of gallol-functionalized PSAs with underwater adhesion.

Abstract Background Limited data are available for risk stratification in patients with atrial fibrillation (AF) and combined heart failure with preserved ejection fraction (HFpEF). We aimed to explore the prognostic utility of high-sensitivity cardiac troponin I (hs-cTnI) in patients with newly detected AF and concomitant HFpEF. Methods From August 2014 to December 2016, 2,361 patients with newly detected AF were polled in a retrospective single-center registry. Of which, 634 patients were eligible for HFpEF diagnosis (HFA-PEFF score ≥ 5) and 165 patients were excluded with exclusion criteria. Finally, 469 patients are classified into elevated or non-elevated hs-cTnI groups based on the 99th percentile upper reference limit (URL). The primary outcome was the incidence of major adverse cardiac and cerebrovascular events (MACCE) during follow-up. Results In 469 patients, 295 were stratified into the non-elevated hs-cTnI group (

Background: Early risk stratification is necessary for optimal determination of the treatment strategy in cardiogenic shock (CS) complicating acute coronary syndrome (ACS). Therefore, we evaluated the prognostic impact of an intra-aortic balloon pump on the cardiogenic shock (IABP-SHOCK) II score according to the treatment strategies in ACS complicated by CS using the RESCUE (REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy of left ventricular assist device for Korean patients with cardiogenic shock) registry. Methods: The RESCUE registry contains multicenter observational retrospective and prospective cohorts that include 1247 patients with CS from 12 centers in Korea. A total of 865 patients with ACS complicated by CS were selected and stratified into low-, intermediate- and high-risk categories according to their IABP-SHOCK II scores and then according to treatment: non-mechanical support, IABP, and extracorporeal membrane oxygenators (ECMOs). The primary outcome was all-cause mortality during follow-up. Results: The observed mortality rates for the low-, intermediate-, and high-IABP-SHOCK II score risk categories were 28.8%, 52.4%, and 69.8%, respectively (p < 0.01). Patients in the non-mechanical support and IABP groups showed an increasingly elevated risk of all-cause mortality as their risk scores increased from low to high. In the ECMO group, the risk of all-cause mortality did not differ between the intermediate- and high-risk categories (HR = 1.21, 95% CI: 0.81–1.81, p = 0.33). The IABP-SHOCK II scores for the non-mechanical support and IABP groups showed a better predictive performance (area under curve [AUC] = 0.70, 95% CI: 0.65–0.76) for mortality compared with the EMCO group (AUC = 0.61, 95% CI 0.54–0.67; p-value for comparison = 0.02). Conclusions: Risk stratification using the IABP-SHOCK II score is useful for predicting mortality in ACS complicated by CS when patients are treated with non-mechanical support or IABP. However, its prognostic value may be unsatisfactory in severe cases where patients require ECMOs.

Abstract Background Combination therapies comprising multiple methods, such as photodynamic therapy have been applied to be complements chemotherapy as they increase the therapeutic efficiency by enabling the intelligent drug delivery to target sites by exposing the photosensitizer to light and activating it in the tumor tissue. This study evaluated in vitro photodynamic therapy of methylene blue (MB)-loaded acetyl resistant starch (ARS) nanoparticles (NPs). Methods ARS was synthesized by the reaction between resistant starch (RS) and acetic anhydride. MB-loaded ARS NPs and ARS NPs were prepared by a single emulsion method. Synthesized ARS was measured by NMR. Prepared ARS NPs and MB-loaded ARS NPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction, UV/Vis, and circular dichroism (CD). MB-loaded ARS NPs were treated in mouse colon cancer cells (CT-26) and they were treated under near-infrared (NIR) laser irradiation. Results Synthesis of ARS was confirmed by NMR and the degree of substitutions in the ARS was 7.1. The morphologies of ARS NPs observed by TEM were spherical shapes and the particle sizes of ARS NPs were 173.4 nm with a surface charge of − 17.24 mV. The d-spacing of ARS NPs was smaller than those of RS and the conformational changes of RS occurred by the formation of self-assembled polymeric NPs with induction of CD of the MB by chiral ARS NPs. The phototoxicity of CT-26 cells treated by MB-loaded ARS NPs dramatically decreased in a dose-dependent manner under NIR laser irradiation compared to free MB. Conclusion This study demonstrated the ordered nanosized structures in the ARS NPs and conformational change from random coil structure of RS to alpha-helices one of ARS occurred and CD of the achiral MB was induced. The MB-loaded ARS NPs showed a higher generation of reactive oxygen species (ROS) in the CT-26 cells than free MB with the NIR laser irradiation and resulting in phototoxicity under irradiation.

Background Despite the benefit of culprit‐only percutaneous coronary intervention (PCI) in the CULPRIT‐SHOCK (Culprit Lesion Only PCI Versus Multi‐vessel PCI in Cardiogenic Shock) trial, the optimal revascularization strategy for refractory cardiogenic shock (CS) requiring mechanical circulatory support devices remains controversial. This study aimed to compare clinical outcomes between the culprit‐only and immediate multivessel PCI strategies in patients with acute myocardial infarction complicated by CS who underwent venoarterial‐extracorporeal membrane oxygenation before revascularization. Methods and Results This study included patient‐pooled data from the RESCUE (Retrospective and Prospective Observational Study to Investigate Clinical Outcomes and Efficacy of Left Ventricular Assist Devices for Korean Patients With Cardiogenic Shock) and SMC‐ECMO (Samsung Medical Center–Extracorporeal Membrane Oxygenation) registries. A total of 315 patients with acute myocardial infarction with multivessel disease who underwent venoarterial‐extracorporeal membrane oxygenation before revascularization attributable to refractory CS were included in this analysis. The study population was classified into culprit‐only versus immediate multivessel PCI according to nonculprit lesion treatment strategies. The primary end point was 30‐day mortality or renal‐replacement therapy, and the key secondary end point was 12‐month follow‐up mortality. Among the study population, 175 (55.6%) underwent culprit‐only PCI and 140 (44.4%) underwent immediate multivessel PCI. Compared with culprit‐only PCI, immediate multivessel PCI was associated with significantly lower risks of 30‐day mortality or renal‐replacement therapy (68.0% versus 54.3%; P=0.018) and all‐cause mortality during 12 months of follow‐up (59.5% versus 47.5%; hazard ratio [HR], 0.689 [95% CI, 0.506–0.939]; P=0.018) in patients with acute myocardial infarction and CS who underwent venoarterial‐extracorporeal membrane oxygenation before revascularization. These results were also consistent in the 99 pairs of propensity score–matched population (60.6% versus 43.6%; HR, 0.622 [95% CI, 0.420–0.922]; P=0.018). Conclusions Among patients with acute myocardial infarction with multivessel disease complicated by advanced CS requiring venoarterial‐extracorporeal membrane oxygenation before revascularization, immediate multivessel PCI was associated with lower incidences of 30‐day mortality or renal replacement therapy and 12‐month follow‐up mortality, compared with culprit‐only PCI. Registration Information clinicaltrials.gov. Identifier: NCT02985008.

Abstract To overcome the limitations of the conventional vacuum thermoforming manufacturing method, direct 3D printing of clear aligners has been developed. The present study investigated the thermo-mechanical and viscoelastic properties of a photocurable resin TC-85, which is a new material for the direct 3D printed clear aligners, comparing to a conventional thermoplastic material polyethylene terephthalate glycol. Dynamic mechanical analysis was performed to analyse the mechanical behaviours of the two materials at 37 °C and 80 °C, respectively. Furthermore, the shape memory property of the two materials was evaluated using a U-shape bending test, and the shape recovery ratio for 60 min at 37 °C was calculated. The results indicate that TC-85 can constantly apply a light force to the teeth when used for the 3D printed clear aligners, owing to its flexibility and viscoelastic properties. In addition, it is expected that the force decay induced by repeated insertion of the clear aligners will be reduced and a constant orthodontic force will be maintained. Furthermore, its geometric stability at high temperatures and the shape memory properties provide advantages for the clinical application.

Abstract Background Patellofemoral pain syndrome (PFPS) is defined as pain around the patella while performing activities such as squats, running, and climbing steps. One of the inherent risk factors for PFPS is an excessively pronated foot posture. The aim of this study was to investigate the effect of foot intervention, talonavicular joint mobilization (TJM) and foot core strengthening (FCS), on PFPS. Methods Forty-eight patients with PFPS (mean age, 21.96 ± 2.34 years; BMI, 22.77 ± 2.95 kg/m2) were enrolled in the study. Participants were randomly assigned in a 1:1:1 ratio to three groups, and received 12 sessions of TJM, FCS, and blended intervention at university laboratory for 4 weeks. The primary outcomes were pain while the secondary outcomes were lower extremity function, valgus knee, foot posture, and muscle activity ratio measured at baseline, after 12 sessions, and at the 4-week follow-up. Results The two-way repeated-measures ANOVA revealed significant interactions in all groups (p

ObjectivesWe evaluated the clinical impact of residual non-culprit left main coronary artery disease (LMCAD) on prognosis in patients undergoing emergent percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) complicated by cardiogenic shock (CS).MethodsA total of 429 patients who underwent PCI for AMI complicated by CS was enrolled from 12 centers in the Republic of Korea. The patients were divided into two groups according to presence of non-culprit LMCAD or not: the LMCAD non-culprit group (n = 43) and the no LMCAD group (n = 386). Primary outcome was major adverse cardiac event (MACE, defined as a composite of cardiac death, myocardial infarction, or repeat revascularization). Propensity score matching analysis was performed to reduce selection bias and potential confounding factors.ResultsDuring a 12-month follow-up, a total of 168 MACEs occurred (LMCAD non-culprit group, 17 [39.5%] vs. no LMCAD group, 151 [39.1%]). Multivariate analysis revealed no significant difference in the incidence of MACE at 12 months between the LMCAD non-culprit and no LMCAD groups (adjusted hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.58 to 1.62, p = 0.901). After propensity score matching, the incidence of MACE was still similar between the two groups (HR 0.64; 95% CI 0.33 to 1.23; p = 0.180). The similarity of MACEs between the two groups was consistent across a variety of subgroups.ConclusionsAfter adjusting for baseline differences, residual non-culprit LMCAD does not appear to increase the risk of MACEs at 12 months in patients undergoing emergent PCI for AMI complicated by CS.

Pressure-sensitive adhesives (PSAs) are used in various industries, and have been widely applied in smart devices. In this study, the adhesion properties, viscoelastic properties, and gel fraction of PSAs were investigated after primary and secondary curing to understand their UV-curing behavior. In addition, the impact of concentration of crosslinking agent on the crosslinking density and the degree of crosslinking was investigated. In general, as more crosslinking agent was added, the hardness increased, but this result can be explained by the difference between “crosslinking density” and “degree of crosslinking” at the highest concentration of crosslinking agent actually led to a decrease in “degree of crosslinking”.

Displays in electronic devices visualize digital information, which is essential for humans to ultimately understand and use the Internet of Things (IoT) technology. Along with the evolution of several electrical components for flexible displays, developing flexible pressure-sensitive adhesives (PSA) is also important. In this study, a pattern of crosslinking density was applied to a PSA during the ultraviolet (UV) curing process to secure adhesion, transparency, stress relaxation, and supplement the strain recovery performance. We measured the modulus of each pattern region by atomic force microscopy (AFM) and confirmed whether the UV pattern PSA was prepared through the implementation of differential crosslinking density. Additionally, we measured dynamic mechanical analysis (DMA) strain recovery test, rheometer, peel strength, probe tack, and transmittance to confirm the effect of the given crosslinking density pattern on the overall physical properties of PSA.

Abstract Background Limited data are available on the clinical significance of lactate clearance (LC) in patients with cardiogenic shock (CS). This study investigated the prognostic role of LC in CS patients. Methods We analyzed data from 628 patients in the RESCUE registry, a multicenter, observational cohort enrolled between January 2014 and December 2018. Univariable logistic regression analysis was performed to determine the prognostic implications of 24 h LC, and then patients were divided into two groups according to the cut-off value of 24 h LC (high lactate clearance [HLC] group vs. low lactate clearance [LLC] group). The primary outcome was in-hospital mortality. We also assessed all-cause mortality at 12 month follow-up and compared the prognostic performance of 24 h LC according to initial serum lactate level. Results In the univariable logistic regression analysis, 24 h LC was associated with in-hospital mortality (odds ratio 0.989, 95% confidence interval [CI] 0.985–0.993, p 5 mmol/L than in those with serum lactate ≤ 5 mmol/L (c-statistics of initial serum lactate > 5 mmol/L = 0.782 vs. c-statistics of initial serum lactate ≤ 5 mmol/L = 0.660, p = 0.011). Conclusions Higher LC during the early phase of CS was associated with reduced risk of in-hospital and 12 month all-cause mortalities. Patients with LC ≥ 64% during the 24 h after CS onset could expect a favorable prognosis, especially those with an initial serum lactate > 5 mmol/L. Trial registration: RESCUE (REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy of left ventricular assist device for Korean patients with cardiogenic shock), NCT02985008, Registered December 5, 2016—retrospectively and prospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT02985008

OBJECTIVES Although an association is known to exist between metabolic syndrome (MetS) and heart failure (HF) risk, large longitudinal studies are limited. We investigated metabolic status as a risk factor for HF in middle-aged male and female and considered sex differences in various risk factors for HF using nationwide real-world data. METHODS Data obtained from the Korean National Health Insurance Service from 2009 to 2016 were analyzed. A total of 2,151,597 middle-aged subjects (between 50 and 59 years old) were enrolled. Subjects were divided into 3 groups (normal, pre-MetS, and MetS). Cox proportional hazard models were used to estimate the association between MetS and incident HF after adjusting for clinical risk factors. RESULTS At baseline, MetS existed in 23.77% of male and 10.58% of female. Pre-MetS and MetS increased the risk of HF: the hazard ratios of pre-MetS for incident HF were 1.508 (95% confidence interval [CI], 1.287 to 1.767) in male and 1.395 (95% CI, 1.158 to 1.681) in female, and those of MetS were 1.711 (95% CI, 1.433 to 2.044) in male and 2.144 (95% CI, 1.674 to 2.747) in female. Current smoking, a low hemoglobin level, underweight (body mass index

Abstract 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

Background Several studies have shown that obesity is associated with better outcomes in patients with cardiogenic shock (CS). Although this phenomenon, the “obesity paradox,” reportedly manifests differently based on sex in other disease entities, it has not yet been investigated in patients with CS. Methods and Results A total of 1227 patients with CS from the RESCUE (Retrospective and Prospective Observational Study to Investigate Clinical Outcomes and Efficacy of Left Ventricular Assist Device for Korean Patients With Cardiogenic Shock) registry in Korea were analyzed. The study population was classified into obese and nonobese groups according to Asian Pacific criteria (BMI ≥25.0 kg/m2 for obese). The clinical impact of obesity on in‐hospital mortality according to sex was analyzed using logistic regression analysis and restricted cubic spline curves. The in‐hospital mortality rate was significantly lower in obese men than nonobese men (34.2% versus 24.1%, respectively; P=0.004), while the difference was not significant in women (37.3% versus 35.8%, respectively; P=0.884). As a continuous variable, higher BMI showed a protective effect in men; conversely, BMI was not associated with clinical outcomes in women. Compared with patients with normal weight, obesity was associated with a decreased risk of in‐hospital death in men (multivariable‐adjusted odds ratio [OR], 0.63; CI, 0.43–0.92 [P=0.016]), but not in women (multivariable‐adjusted OR, 0.94; 95% CI, 0.55–1.61 [P=0.828]). The interaction P value for the association between BMI and sex was 0.023. Conclusions The obesity paradox exists and apparently occurs in men among patients with CS. The differential effect of BMI on in‐hospital mortality was observed according to sex. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02985008.

Background: Limited data is available between metabolic syndrome (MetS) and the development of peripheral arterial disease (PAD) or venous thromboembolism (VTE) in the Asian population. We investigated the incidence of PAD and VTE according to the prevalence of MetS and evaluated the impact of individual components in MetS on the development of PAD and VTE using Korean national data. Methods: Data obtained from national health screening examinations of the Korean National Health Insurance Service from January 1, to December 31, 2009. In total, 9,927,538 participants, 7,830,602 participants were included in this study and the incidence rate of PAD and VTE was investigated retrospectively during a 7-year follow-up. Using the National Cholesterol Education Program Adult Treatment Panel III criteria, patients were placed into one of three groups depending on MetS component numbers: 0 (normal), 1–2 (Pre-MetS), or 3–5 (MetS). Results: The incidence rates of PAD and VTE in MetS were 2.25% and 0.71%, respectively. After multivariable adjustment, the risk of PAD was significantly associated with MetS (hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.42–1.49), the risk of VTE was not associated with MetS (HR 1.01, 95% CI 0.96–1.05). When subgroup analyses were conducted according to MetS components, elevated fasting glucose (HR 1.26, 95% CI 1.23–1.27), abdominal obesity (HR 1.15, 95% CI 1.12–1.17), and elevated blood pressure (HR 1.13, 95% CI 1.12–1.15) were the most related to PAD. Abdominal obesity (HR 1.104, 95% CI 1.064–1.146) was associated with an increased risk of VTE. Conclusions: MetS was significantly associated with an increased incidence rate of PAD among the general Korean population. On the other hand, MetS was not associated with the VTE incidence rate. Of the MetS components, only abdominal obesity was a significant predictor of VTE.

Background: Elevated soluble suppression of tumorigenicity 2 (sST2) levels may predict mortality in heart failure (HF) patients. The AFIAS ST2 assay (AFIAS ST2, Boditech Med Inc., Chuncheon, Korea) and ichroma ST2 assay (ichroma ST2, Boditech Med Inc.) are newly developed point-of-care (POC) assays for measuring sST2 level. We evaluated the performance of these assays, in terms of cut-off validation and prognosis, and compared them with that of the Presage ST2 assay (Presage ST2, Critical Diagnostics, San Diego, CA, USA). Methods: We validated the US FDA-claimed sST2 clinical cut-off of 35 ng/mL using 420 serum samples (298 samples from the universal sample bank of the American Association for Clinical Chemistry and 122 samples from reference individuals from Konkuk University Medical Center). We compared AFIAS ST2 and ichroma ST2 with Presage ST2, using 206 samples from patients with HF. We assessed prognosis using the three assays in 252 samples from the Barcelona ambulatory HF cohort subsets. Results: The upper reference limits of AFIAS ST2 and ichroma ST2 were within the clinical cut-off of Presage ST2. The results of AFIAS ST2 and ichroma ST2 were highly correlated with those of Presage ST2 (r = 0.82 and 0.81, respectively). Based on this cut-off, all three assays predicted cardiovascular death. Conclusions: The new POC assays, AFIAS ST2 and ichroma ST2, would be useful in clinical practice for managing HF patients, with performances equivalent to that of Presage ST2.

Deteriorated facility maintenance is a critical social issue in advanced countries. Its cost increases when considering the social consequences in terms of asset value and direct maintenance costs. Data from Korea’s Ministry of Land, Infrastructure, and Transport shows that there were 3454 bridges aged 30 years or over in Korea in 2017; this number will increase to 10,961 by 2027. In thirty years, maintenance costs will be incurred for more than 32,000 old bridges in Korea. These trends are also observed in the US, Japan, and Korea. Diverse studies have been conducted to predict the residual life of old bridges via bridge performance evaluation and load-carrying capacity assessments. However, criteria for evaluating bridge performance and verifying the effect of bridge maintenance are yet to be established due to two reasons. First, most studies on performance evaluation, maintenance, and rehabilitation techniques have been performed on limited specimens from building elements or through small-scale simulations that do not reflect the deterioration factors of complex materials in diverse environments. Second, the performance evaluation of bridges is difficult compared to quantitative state evaluations. As a method of predicting the future performance of aged concrete bridges, it is effective to understand the actual aged bridges through experiments, and this study intends to propose the method.

The era of the Internet of Things (IoT) is becoming a reality, and the display equipment is at its center. The display device is the window that connects the IoT and humans, and is evolving into various form factors convenient to human use, such as foldable mobile phone, flexible wearable device, paper-like display, and rollable TV. Even though transparent flexible electrodes and substrates have been developed, their assembly remains a challenge. Therefore, the importance of optically clear acrylic pressure-sensitive adhesives (PSAs) that ensure device integrity by easily stretched and mitigating the stress during repeated stretching and bending process is being emphasized. In this study, elongation and recovery features were identifiable as key flexible properties of PSAs. These properties were estimated by measuring shear strain and strain recovery using a universal testing machine and by dynamic mechanical analytics respectively. Compared to conventional UV metal halide curing, a newly introduced ultraviolet light-emitting diode (UV LED) curing process resulted in different PSA property variables, namely UV exposure intensity and UV exposure time. Fully cured acrylic PSA realized under UV LED exposure level 30 for 8 s demonstrated the highest shear strain with excellent strain recovery of ~23,500% and 94% respectively. Under these conditions, effective material adhesion performance was achieved while retaining optical transparency and thus fulfilling the dual property requirement for non-opaque material adhesiveness necessary for use in flexible displays.

Abstract 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.

Cellulose-based nanopaper with high moisture and thermal resistance and high tensile properties has many applications in the food packaging industry, electronics, and biosensors. The objective of the present work is to produce and characterize the disintegrated bacterial cellulose-based nanopaper film and its ZnO bionanocomposite prepared without and with compression. Addition of ZnO nanoparticles into nanopaper and compression improved the tensile and thermal properties and moisture resistance of the bionanocomposite. Compressed nanopaper film with 1.2 wt% ZnO had the highest tensile strength (TS) of 94.2 MPa and tensile modulus (TM) of 10.1 GPa. These TS and TM values were 109% and 172% higher than those of non-compressed film due to an increase in the crystal structure. Surprisingly this bionanocomposite also demonstrates higher elongation at break in comparison to the nanopaper film. All samples show good rollability and bendability. Compressed bionanocomposite had higher moisture resistance than non-compressed one. This work promotes an environmentally friendly bionanocomposite film which has good potential for food packaging applications.

UV-polymerizable and UV-crosslinkable pressure-sensitive adhesive acrylic compositions are widely applied for high-quality carrier-free films, one-sided or double-sided self-adhesive tapes. Comprehensive studies of the properties of novel acrylic PSAs for carrier-free films or adhesive tapes were carried out. Solvent-free acrylic pressure-sensitive adhesive layers were UV-crosslinked using various photoreactive crosslinking agents. Polymer content during UV-polymerization, prepolymers viscosity, temperature changes of prepolymer during UV-initiated polymerization process were investigated. The chemical structure of prepolymer and polymerized acrylic film were examined using FTIR spectroscopy. Prepolymer mixtures were transferred on the transparent carriers to form 1 mm thick polymer films, and then UV-crosslinked after the addition of the selected acrylic crosslinker. Final adhesive films were then tested to evaluate their functional properties as the tack, peel adhesion, and shear strength at 20 °C and 70 °C. From the results reveal that both concentrations of acrylic acid in the prepolymer, and cross-linking agent in the final polymer layer, have a significant influence on the functional properties of the produced PSA films.

Developing a conductive cellulose film without any metal compounds remains challenging, though in great demand. However, cellulose film prepared from bacterial cellulose (BC) powder without any metal compounds has poor tensile, physical, and electrical properties, thus limiting its application. Herein, this study aims to prepare and characterize an all-cellulose film from 2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized bacterial cellulose (TOBC) powders without adding metal compounds and treated by ultrasonication. TOBC powders are sonicated with various powers of 250, 500, and 750 W for 20 min without any other substance. It was proved that increasing the ultrasonication power level resulted in a significant improvement in the properties of the film. The ultrasonication of 750 W increased tensile strength by 85%, toughness by 308%, light transmittance by 542%, and electrical conductivity by 174% compared to the nonsonicated film. A light-emitting diode connected to a power source through this sonicated film was much brighter than that connected via a nonsonicated film. For the first time, this study reports the preparation of electrically conductive, transparent, strong, and bendable pure TOBC films by increasing ultrasonic power for environmentally friendly electronic devices application.

Abstract 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.

Background Length of hospitalization for patients with lower back pain sustained in road traffic accidents was assessed clinically. Methods In total, 170 patients with lower back pain injury sustained in road traffic accidents, were included in the study. They were divided into 2 groups: Group A with a shorter hospitalization period (1?7 days) and Group B with a longer hospitalization period (8?14 days). Each group was treated daily with traditional Korean medicine including: acupuncture, herbal acupuncture, herbal decoction medicine, and chuna treatment. To compare the treatment effects between the 2 groups, health-related quality of life, Oswestry disability index, and numeric rating scale were used. Statistical analysis between the 2 groups was assessed using Chi-square test, independent t test, and paired t test. Results After hospitalization, Group A and Group B both showed a significant increase in their health-related quality of life scores and significant decreases in Oswestry disability index and numeric rating scale scores. In addition, Group B, with a longer hospitalization period than Group A, showed a significant improvement over Group A in its health-related quality of life and numeric rating scale scores. Conclusions This study suggests that control of pain caused by lower back injury sustained in a road traffic accident, may be more effectively achieved in patients receiving 8-14 days of hospitalization and traditional Korean medicine treatment, compared to those receiving < 7 days of hospitalization treatment. In the future, more systematic and large-scale studies are needed to ascertain the effects of other variables.

The use of ultraviolet radiation (UV) technology for the crosslinking of acrylic pressure-sensitive adhesives (PSA) is the one of various crosslinking methods, being the alternative to the conventional crosslinking process of solvent-based acrylic systems. It also requires a photoinitiator to absorb the impinging UV and induce photocrosslinking. As previously mentioned, a photoinitiator is one of the important and necessary components in UV-inducted crosslinking of acrylic pressure-sensitive adhesives. The activity of multifunctional conventional saturated photoinitiators of type I and type II, especially benzophenone-based in the photoreactive UV-crosslinkable acrylic PSA was described. The effect of the multifunctional type-II photoinitiators on the acrylic PSA, such as tack, peel adhesion and shear strength were summarized.

The objectives of this study are to improve the thermal and mechanical properties of epoxy/fumed silica composite with different surface treatments of fumed silica. The addition of silica nanoparticles improved the thermal stability of the composite and slowed down the pyrolysis process. The crosslinking density and Tg of the epoxy/fumed silica composites increased because of the interfacial interaction between the PDMS-treated fumed silica particles and the epoxy matrix. The flexural strength of the epoxy nanocomposite was very high even at a low silica content because of the strong interactions between the PDMS-treated fillers and the epoxy matrix. These strong interfacial interactions originate from the attractive forces between the polymer and the filler. Therefore, the polymer nanocomposite containing the PDMS-treated fumed silica is shown to be sufficiently commercially promising.

Background This study was designed to evaluate the clinical effectiveness of traditional Korean medicine treatment for lumbar spinal stenosis as assessed by radiological criteria. Methods This was an observational study of 122 patients who were diagnosed with lumbar spinal stenosis and admitted to Jaseng Hospital between January 2016 and June 2017. They were analyzed according to sex, age, cause of disease, disease stage, length of admission, type of stenosis, morphological grade, and dural sac cross-sectional area. All patients were treated with traditional Korean medicine. Patients were assessed with the Numeric Rating Scale (NRS), Oswestry Disability Index (ODI) and EQ-5D before and after treatment. Results Regarding the distribution of the factors analyzed, these were of note: more females than males (1:3.52); and highest proportions were age more than 70 years (37.70%), cause of lumbar spinal stenosis unknown (67.21%), and subacute stage (42.62%). Comparing before and after treatment, the NRS score for low back and pelvic pain decreased from 6.14 ± 1.71 to 4.28 ± 1.91 (p < 0.001), and the NRS score for radiating pain and numbness decreased from 6.27 ± 1.61 to 2.02 ± 1.54 (p < 0.001). ODI decreased from 46.86 ± 19.40 to 33.63 ± 18.66 (p < 0.001), and gait-related ODI decreased from 3.34 ± 1.23 to 2.80 ± 1.11 (p < 0.001). There were no statistically significant differences in improvement of the NRS, ODI, gait-related ODI, and EQ-5D for morphological grade and dural sac cross-sectional area. Conclusions Traditional Korean medicine is effective treatment for patients with lumbar spinal stenosis. Even in patients with severe radiological findings, it is possible to reduce pain and improve quality of life.

There are various thin coating technologies, among which the UV coating technology is attracting attention in next-generation industries. In order to utilize the UV coating system stably, it is necessary to analyze and address the problems of surface oxygen inhibition and UV penetration, which lead to irregular curing characteristics. For this, three different UV-curing resins were selected. The effects of the structural difference of the material and change in the initiator content along the thickness direction during UV curing were evaluated by the sliding cutting technique (which involves cutting the coated surface at a superfine angle). Thus, it was confirmed that the effect of surface oxygen inhibition during UV curing is very large on the surface. Here, surface curing could be induced by increasing the functional group concentration and introducing a hybrid curing system. With increasing initiator content, the formation of a material with a high curing density on the surface and an irregular hardening structure in the deep part was confirmed. Therefore, the sliding cutting technique is a very effective approach to control the thickness profile of a UV coating system. Keywords: Depth profile, UV coating, Slide cutting, Surface and interfacial cutting analysis system, Complementary curing, Initiator effect

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 Pseudomonas sp. B14-6 revealed two PHA-production-related gene clusters containing four PHA synthase genes (phaC). Pseudomonas sp. B14-6 produced poly(6% 3-hydroxybutyrate-co-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-co-mcl PHA determined a glass transition temperature (Tg) 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 × 104, weight average molecular weight of 9.1 × 104, and polydispersity index value of 2.5. Overall, the novel Pseudomonas sp. B14-6 produced a polymer with high medium-chain-length content, low Tg, and low crystallinity, indicating its potential use in medical applications.

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 Ralstonia eutropha 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 R. eutropha 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.

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.

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.

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.

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.

Carbon fiber reinforced plastic (CFRP) is currently used as a lightweight material in various parts of automobiles. However, fiber reinforced plastic (FRP) material may be damaged at the time of joining via mechanical bonding; therefore, adhesion is important. When bonding is conducted without surface CFRP treatment, interfacial destruction occurs during which the adhesive falls off along with the CFRP. Mechanical strength and fracture shape were investigated depending on the surface treatment (pristine, plasma treatment times, and plasma treatment times plus epoxy modified primer coating). The plasma treatment effect was verified using the contact angle and X-ray photoelectron spectroscopy. The wettability of the epoxy modified primer (EMP) coating was confirmed through surface morphology analysis, followed by observation of mechanical properties and fracture shape. Based on test data collected from 10 instances of plasma treatment, the EMP coating showed 115% higher strength than that of pristine CFRP. The adhesive failure shape also changed from interfacial failure to mixed-mode failure. Thus, applying an EMP coating during the automotive parts stage enhances the effect of CFRP surface treatment.

The prognostic values of the left ventricular ejection fraction (LVEF) and end-diastolic dimension (LVEDD) have primarily been shown among patients with chronic heart failure (HF), with little representation of patients with acute HF (AHF). Therefore, we investigated the value of these echocardiographic parameters in predicting clinical outcomes among patients in the Korean Heart Failure (KorHF) Registry.The KorHF Registry consists of 3,200 patients who were hospitalized with AHF from 2005 to 2009. The Kaplan-Meier method was used to estimate survival and readmission, and differences were assessed using the log-rank test. Predictors of survival were identified using univariate and multivariate Cox proportional hazards regression analyses.Echocardiograms from 2,910 of the 3,200 patients (90.9%) were evaluated. The median LVEF and LVEDD (37% and 56 mm, respectively) were used as cut-offs for the binary transformation of each parameter. The cumulative death-free survival rates for all patients did not significantly differ based on LVEF or LVEDD quartiles; however, an LVEF greater than the median was associated with a better prognosis in ischemic HF patients (log-rank test; p = 0.039). Among ischemic HF patients, LVEF (dichotomized) was a significant predictor of death in a Cox model after adjusting for a history of HF, age, systolic blood pressure (SBP), serum sodium, sex, diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), chronic kidney disease (CKD), acute myocardial infarction (AMI), atrial fibrillation (Af) and anemia (hazard ratio (HR) 1.475, 95% confidence interval (CI) 1.099-1.979, p = 0.010). The cumulative readmission-free survival rates significantly differed among ischemic HF patients only when based on LVEDD quartiles (log-rank test; p = 0.001). In multivariate Cox proportional hazards regression analyses, LVEDD (dichotomized) remained a significant variable only among patients with ischemic HF after adjusting for sex, age, AMI, DM, COPD, serum sodium, SBP, blood urea nitrogen (BUN) and anemia (HR 1.401, 95% CI 1.067-1.841, p = 0.015).Among ischemic AHF patients in the KorHF Registry, LVEF is associated with mortality, whereas LVEDD is only associated with readmission in a binary transformed form.