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1.
J Colloid Interface Sci ; 592: 440-447, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33711646

RESUMO

The high cost and relative scarcity of platinum (Pt) restrict large-scale commercialization of fuel cells, which has spurred researchers to develop low-cost alternatives integrating with high hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) catalytic activity. Herein, we performed density functional theory (DFT) calculations to explore the electrocatalytic activity of graphyne nanotubes (GyNTs). Several GyNTs were found to be potential metal-free electrocatalysts, with both HER and ORR activity superior to Pt. Moreover, we revealed a linear relationship between the Gibbs free energy change of O2 adsorption (ΔGOOH) and binding energy of H adsorption (ΔEH), which could be attributed to the fact that both the CO bond of OOH adsorption and the CH bond of H adsorption are single bonds. Therefore, ΔEH is proposed as a general descriptor for the rational design of bifunctional graphyne materials toward HERs and ORRs. Our findings provide a simple strategy for the rational design of bifunctional materials.

2.
J Toxicol Sci ; 46(3): 125-129, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33642518

RESUMO

Cadmium (Cd) is a toxic heavy metal, long-term exposure to which causes renal damage associated with disruption in gene expression. Transcription factors whose activities were altered in the kidneys of mice exposed to Cd for 3 months were assessed using protein/DNA-binding assays. Female C57BL/6J mice were exposed to 300 ppm Cd in the diet for 3 months. Nuclear extracts of kidney were used for protein/DNA-binding assays. The concentration of Cd was approximately 100 ppm in mouse kidney, a level that did not induce renal toxicity. Among the 345 transcription factors evaluated, five transcription factors showed over a two-fold increase in their activities and 14 transcription factors showed a half-fold change in their activities after Cd exposure. These findings may provide new information about the causative transcription factors associated with Cd renal toxicity.

3.
J Prev Med Public Health ; 54(1): 8-16, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33618494

RESUMO

This article aims to introduce the inception and operation of the COVID-19 International Collaborative Research Project, the world's first coronavirus disease 2019 (COVID-19) open data project for research, along with its dataset and research method, and to discuss relevant considerations for collaborative research using nationwide real-world data (RWD). COVID-19 has spread across the world since early 2020, becoming a serious global health threat to life, safety, and social and economic activities. However, insufficient RWD from patients was available to help clinicians efficiently diagnose and treat patients with COVID-19, or to provide necessary information to the government for policy-making. Countries that saw a rapid surge of infections had to focus on leveraging medical professionals to treat patients, and the circumstances made it even more difficult to promptly use COVID-19 RWD. Against this backdrop, the Health Insurance Review and Assessment Service (HIRA) of Korea decided to open its COVID-19 RWD collected through Korea's universal health insurance program, under the title of the COVID-19 International Collaborative Research Project. The dataset, consisting of 476 508 claim statements from 234 427 patients (7590 confirmed cases) and 18 691 318 claim statements of the same patients for the previous 3 years, was established and hosted on HIRA's in-house server. Researchers who applied to participate in the project uploaded analysis code on the platform prepared by HIRA, and HIRA conducted the analysis and provided outcome values. As of November 2020, analyses have been completed for 129 research projects, which have been published or are in the process of being published in prestigious journals.


Assuntos
/prevenção & controle , Seguradoras/estatística & dados numéricos , Internacionalidade , /transmissão , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Avaliação de Resultados em Cuidados de Saúde/normas , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Qualidade da Assistência à Saúde/normas , Qualidade da Assistência à Saúde/estatística & dados numéricos , República da Coreia
4.
J Prev Med Public Health ; 54(1): 17-21, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33618495

RESUMO

In 2020, the coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented disruptions to global health systems. The Korea has taken full-fledged actions against this novel infectious disease, swiftly implementing a testing-tracing-treatment strategy. New obligations have therefore been given to the Health Insurance Review and Assessment Service (HIRA) to devote the utmost effort towards tackling this global health crisis. Thanks to the universal national health insurance and state-of-the-art information communications technology (ICT) of the Korea, HIRA has conducted far-reaching countermeasures to detect and treat cases early, prevent the spread of COVID-19, respond quickly to surging demand for the healthcare services, and translate evidence into policy. Three main factors have enabled HIRA to undertake pandemic control preemptively and systematically: nationwide data aggregated from all healthcare providers and patients, pre-existing ICT network systems, and real-time data exchanges. HIRA has maximized the use of data and pre-existing network systems to conduct rapid and responsive measures in a centralized way, both of which have been the most critical tactics and strategies used by the Korean healthcare system. In the face of new obligations, our promise is to strive for a more responsive and resilient health system during this prolonged crisis.


Assuntos
/prevenção & controle , Trocas de Seguro de Saúde/normas , Pandemias/prevenção & controle , /epidemiologia , Assistência à Saúde/normas , Assistência à Saúde/tendências , Trocas de Seguro de Saúde/tendências , Humanos , Pandemias/estatística & dados numéricos , República da Coreia
5.
Artigo em Inglês | MEDLINE | ID: mdl-33533585

RESUMO

A platform is introduced for bilayered coacervation of oppositely charged nanoplatelets (NPLs) at the oil-water interface. To this end, we synthesized two types of zirconium hydrogen phosphate (ZrHP) NPLs, cationically charged NPLs (CNPLs), and anionically charged NPLs (ANPLs) by conducting surface-initiated atom transfer radical polymerization. Taking advantage of the platelet geometry and controlled wettability, we demonstrated that ANPLs and CNPLs coacervate themselves to form a bilayered NPL membrane at the interface, which was directly confirmed by confocal laser scanning microscopy. Via theoretical consideration using the hit-and-miss Monte Carlo method, we determined that electrostatic attraction-driven coacervation of ANPLs and CNPLs at the interface shows a minimum attachment energy of ∼ -106 kBT, which is comparable to the cases where NPLs charged with the same type of ions are attached. Finally, this unique and novel interfacial coacervation behavior allowed us to develop a pH-responsive smart Pickering emulsion system.

6.
Dermatology ; : 1-8, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33556947

RESUMO

BACKGROUND: Emerging data suggest that inflammatory bowel disease (IBD) and psoriasis are associated, sharing common genetic predispositions and immunological mechanisms. However, concrete data on psoriasis risk in IBD patients compared to the general population are limited. OBJECTIVE: We investigated the risk of developing psoriasis in IBD patients compared to controls without IBD. METHODS: Using the Korean National Health Insurance Database, patients diagnosed with Crohn's disease (CD) or ulcerative colitis (UC) between 2005 and 2008 were age- and sex-matched 1:4 to non-IBD subjects from 2003 to 2018. IBD patients were defined by combining the International Classification of Diseases 10th revision code and at least one prescription of IBD-specific medications. Disease phenotypes, including psoriasis severity and psoriatic arthritis, were also identified. We investigated newly diagnosed psoriasis from 2009 to 2018. Incidence rates and risk of psoriasis were assessed with multivariate Cox regression models. Subgroup analyses for age and sex, and sensitivity analysis involving tumor necrosis factor (TNF) inhibitor-naïve patients were performed. RESULTS: During nearly a decade of follow-up, 20,152 IBD patients were identified (14,619 [72.54%] UC and 5,533 [27.46%] CD). Among them, 439 patients were newly diagnosed with psoriasis (incidence rate of 217.68 per 100,000 person-years and 228.62 per 100,000 person-years for UC and CD, respectively). The psoriasis risk was higher in IBD patients than in the matched controls (adjusted hazard ratio, aHR, 2.95, 95% confidence interval, CI, 2.60-3.33). Moreover, IBD patients aged <30 years were at an increased risk (aHR 3.35, 95% CI 2.58-4.35), a trend that was unchanged across all psoriasis phenotypes. Sensitivity analysis of TNF inhibitor-naïve patients revealed consistent results. CONCLUSIONS: IBD patients were more likely to develop psoriasis compared to non-IBD subjects, including younger patients at an elevated risk regardless of TNF inhibitor use. This advocates the interplay between IBD and psoriasis; thus, inspection of cutaneous manifestation and dermatological consultation may be helpful in IBD patients at risk.

7.
J Dermatol ; 48(4): 431-438, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33608949

RESUMO

Inflammatory bowel disease (IBD) presents with various extraintestinal manifestations. As part of them, various skin diseases are suggested to be related to IBD. We aimed to identify the epidemiology and risk of developing skin manifestations in patients with IBD. We used Korean insurance claims data and selected patients with IBD and age/sex-matched non-IBD subjects between 2013 and 2017 using the diagnosis code and prescription records of IBD-specific medications. The prevalence and risk of concurrent skin diseases were estimated. We identified 64 837 patients with IBD. Reactive skin eruptions including pyoderma gangrenosum and erythema nodosum were associated with IBD with highest odds ratios among three categories of reactive, inflammatory, and autoimmune skin diseases. Inflammatory skin diseases including rosacea, psoriasis, atopic dermatitis, hidradenitis suppurativa, and acne conglobata were significantly associated with IBD, but the association was less marked compared to reactive skin eruptions. The patients with IBD also had a higher risk of autoimmune skin diseases including vitiligo and alopecia areata than non-IBD subjects. We determined that IBD was related to various skin diseases including reactive, inflammatory, and autoimmune skin diseases. Considering these relationships can allow better management of patients with IBD and comorbid skin diseases.

8.
Phys Chem Chem Phys ; 23(5): 3543-3551, 2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33514955

RESUMO

A series of Ir- and Pt-based blue phosphorescent materials were theoretically investigated by means of density functional theory (DFT) calculations to improve their chemical stability in the excited state. High energy splitting between the lowest triplet state (T1 state), generally a metal-to-ligand charge transfer state (3MLCT), and the triplet metal-centred state (3MC) can prohibit ligand dissociation and suppress the decomposition reaction from the 3MC state to the dissociated S0. Here, we suggest a new design strategy to improve the chemical stability of blue phosphorescent materials in the excited state. Introducing inter- and intra-ligand interactions in Ir and Pt complexes can dramatically increase the ΔE(3MC-T1) because attractive or repulsive couplings arising from intra- or inter-ligand interactions can effectively prevent the out-of-plane bending vibrational mode in Ir complexes and the ring deformation vibrational mode in Pt complexes. A ΔE(3MC-T1) values of 18.62 kcal mol-1 for an Ir complex and 22.86 kcal mol-1 for a Pt complex from the T1 energy were obtained while the T1 energy was maintained in the blue region. To the best of our knowledge, these are the highest ΔE(3MC-T1) values reported to date. We believe that the present research provides profound insights into the excited state chemical stability of deep blue phosphorescent materials that could be implemented to improve device lifetimes.

9.
Chem Commun (Camb) ; 57(14): 1774-1777, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33475118

RESUMO

Nitrogen doped carbon functionalized CoSe2 nanowires (CoSe2@N-C NWs), which act as potential oxygen evolution reaction (OER) catalysts with a large current density and high stability have been reported. Owing to the collaborative optimization of electrical conductivity, free adsorption energy and binding strength of OER intermediates, the prepared CoSe2@N-C NWs exhibit an enhanced 6.61-fold catalytic activity compared to the pristine CoSe2 NW electrode in 1.0 M KOH solution at the overpotential of 340 mV.

10.
J Am Chem Soc ; 143(5): 2413-2422, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33507066

RESUMO

The development of activatable photosensitizers to allow for the reversible control of singlet oxygen (1O2) production for photodynamic therapy (PDT) faces great challenges. Fortunately, the flourishing field of supramolecular biotechnology provides more effective strategies for activatable PDT systems. Here, we developed a new reversible PDT on a switch that controls the 1O2 generation of self-assembled albumin nanotheranostics in vitro and in vivo. A new molecular design principle of aggregation-induced self-quenching photochromism and albumin on-photoswitching was demonstrated using a new asymmetric, synthetic diarylethene moiety DIA. The photosensitizer porphyrin and DIA were incorporated as building blocks in a glutaraldehyde-induced covalent albumin cross-linking nanoplatform, HSA-DIA-porphyrin nanoparticles (NPs). More importantly, the excellent photoswitching property of DIA enables the resultant nanoplatform to act as a facile, switchable strategy for photodynamic-immunotherapy.

11.
Lab Chip ; 21(2): 378-384, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33313636

RESUMO

A microfluidic chip integrated with a microelectrode and a cathodic photoelectrochemical (PEC) biosensor for the ultrasensitive detection of non-small cell lung cancer cytokeratin fragments based on a signal amplification strategy was designed. The mechanism for signal amplification is developed based on the p-n junction of AgI/Bi2Ga4O9, with dissolved O2 as an electron acceptor to produce the superoxide anion radical (˙O2-) as the working microelectrode. By combining this with a novel superoxide-dismutase-loaded honeycomb manganese oxide nanostructure (SOD@hMnO2) as the co-catalyst signal amplification label, ˙O2- can be catalyzed by SOD via a disproportionation reaction to produce O2 and H2O2; then, hMnO2 is able to trigger the decomposition of H2O2 to generate O2 and H2O. Therefore, the increased O2 promotes the separation of electron-hole pairs via consuming more electrons, leading to an effective enhancement of the cathodic PEC behavior. Under optimum conditions, with the cytokeratin 19 fragments 21-1 (CYFRA 21-1) as the targeted detection objects, the microfluidic cathodic PEC biosensor chip exhibited excellent linearity from 0.1 pg mL-1 to 100 ng mL-1, with a detection limit of 0.026 pg mL-1 (S/N = 3). The exciting thing that this work offers is a new strategy for the detection of other important cancer biomarkers for disease diagnosis and prognosis.

12.
FASEB J ; 35(1): e21236, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33337552

RESUMO

Cadmium (Cd) is an environmental contaminant that causes renal toxicity. We have previously demonstrated that Cd induces renal toxicity by altering transcriptional activities. In this study, we show that Cd markedly inhibited the activity of transcription factor MEF2A in HK-2 human proximal tubule cells, which generated significant cytotoxicity in the cells. This reduction in the nuclear levels of MEF2A protein may be involved in the Cd-induced inhibition of MEF2A activity. We also demonstrate that one of the glucose transporters, GLUT4, was downregulated not only by Cd treatment but also by MEF2A knockdown. Knockdown of SLC2A4, encoding GLUT4, eliminated both cell viability and Cd toxicity. Cd treatment or SLC2A4 deficiency reduced the cellular concentration of glucose. Therefore, the suppression of SLC2A4 expression, which mediates the reduction in cellular glucose, is involved in Cd toxicity. The Cd toxicity induced by the reduction in GLUT4 may be associated with a reduction of cellular ATP levels in HK-2 cells. The levels of Slc2a4 mRNA in the kidney of mice exposed to Cd for 6 or 12 months were significantly lower than those in the control group. These results demonstrate that Cd exerts its cytotoxicity through the suppression in SLC2A4 expression and the subsequent inhibition of MEF2A transcriptional activity. Cd-induced suppression of SLC2A4 expression also reduces cellular ATP levels, partly by reducing glucose levels. This study suggests that the glucose transporter plays an important role in the renal toxicity of Cd, and provides a crucial breakthrough in our understanding of the mechanism of Cd toxicity.

13.
Artigo em Inglês | MEDLINE | ID: mdl-33319448

RESUMO

Electrochemical CO 2 reduction (CO 2 RR) to value-added chemicals offers an efficient way to mitigate global warming and energy supply issues. However, the development of highly efficient electrocatalysts for CO 2 RR to boost reaction efficiency and guide understanding of catalytic mechanism remains a huge challenge. Herein, we demonstrate a NiSn atomic pair electrocatalyst (NiSn-APC) on a hierarchical integrated electrode, which exhibits a synergistic effect in simultaneously promoting the activity and selectivity of CO 2 RR to formate. The NiSn atomic pair consist of adjacent Ni and Sn coordinated with four nitrogen atoms (N 4 -Ni-Sn-N 4 ) respectively, which is confirmed by high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) and extended X-ray absorption fine structure (EXAFS). Typically, the as-prepared NiSn-APC displays an exceptional activity toward CO 2 RR to formate with a turnover frequency of 4752 h -1 , a formate productivity of 36.7 mol h -1 g Sn -1 and an utilization degree of active sites (57.9%), which are superior to the previously reported single-atomic catalysts (SACs). Moreover, both in situ attenuated total reflection-infrared (ATR-IR) spectroscopy and density functional theory (DFT) calculation verify the electron redistribution of Sn imposed by adjacent Ni, which reduces the energy barrier of *OCHO intermediate and makes this potential-determining step thermodynamically spontaneous. The NiSn synergistic catalysis for CO 2 RR in this work provides a successful paradigm for rational design and preparation of atomic pair electrocatalysts with largely enhanced performance.

14.
J Korean Med Sci ; 35(45): e396, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33230987

RESUMO

BACKGROUND: Following the coronavirus disease 2019 (COVID-19) outbreak in Wuhan, China, a total of 637 patients had been diagnosed with the disease in Seoul as of May 2, 2020. Our study aimed to describe the impact of the 3T strategies (preemptive testing, prompt tracing and proper treatment) on the epidemiological characteristics of COVID-19 in Seoul. METHODS: The descriptive and explanatory analysis was carried out on critical indicators such as epidemiological characteristics and key duration of patient status change from January 24 to May 2 in Seoul before and after preemptive testing for patients under investigation associated with COVID-19 clusters. RESULTS: Preemptive testing increased the positive test rate (3.9% to 4.2%), an asymptomatic case at diagnosis (16.9% to 30.6%), and reduced the time from symptom onset to quarantine (4.0 to 3.0 days). Prompt tracing decreased unknown sources of infection (6.9% to 2.8%), the mean number of contacts (32.2 to 23.6), and the time-varying reproduction number R(t) (1.3 to 0.6). With proper treatment, only 2 cases of mortality occurred, resulting in a fatality rate of just 0.3%. CONCLUSION: In the first wave of the COVID-19 pandemic lasting 100 days, the effect of the 3T strategies flattened the curve and decreased the time during which infected individuals were contagious, thereby lowering the R(t) below 1 in Seoul.

15.
Phys Chem Chem Phys ; 22(45): 26605-26613, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33201950

RESUMO

Time-resolved circular dichroism signals (TRCD) in the X-ray regime can directly probe the magnitude and the direction of ring currents in molecules. The electronic ring currents in Mg-porphyrin, generated by a coherent superposition of electronic states induced by a circularly polarized UV pulse, are tracked by a time-delayed circularly polarized attosecond X-ray pulse. The signals are calculated using the minimal coupling Hamiltonian, which directly makes use of transition current densities. The TRCD signals obtained from the left and right circularly polarized light pump have opposite signs, revealing the direction of the ring current. Molecular aromaticity and its role in photochemical reactions such as ring opening or closure can be studied using this technique.

16.
AIDS Care ; : 1-5, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33172283

RESUMO

The epidemiological characteristics of women living with human immunodeficiency virus (HIV) infection have gained little attention as the numbers are small compared with men living with HIV in the Republic of Korea. However, these data are important to achieve effective HIV infection control and to consider the influence of socioeconomic status on HIV transmission. This study utilized the claims database of the Korean National Health Insurance system to analyze women with a newly diagnosed HIV infection during the period 2009-2016. Adherence to antiretroviral agents was calculated using the medication possession ratio. Among 677 women with a newly diagnosed HIV infection, 219 (32.4%) were over 50 years of age; 291 (43.0%) were identified as having acquired immune deficiency syndrome (AIDS). A total of 99 women (14.6%) were National Medical Aid beneficiaries. Optimal medical adherence >95% was found in 62.2% of subjects. Teenage years (odds ratio(OR) 14.9, 95% confidence interval (95CI) 4.9-44.8), AIDS (OR 1.7, 95CI 1.2-2.3), and low economic status requiring National Medical Aid (OR 3.0, 95CI 2.0-4.6) were associated to adherence. Diagnosis prior to 2012 was also associated with poor adherence. In women, particularly young patients with low economic status, extra attention is required to enhance adherence to prescribed medication.

17.
Artigo em Inglês | MEDLINE | ID: mdl-33155344

RESUMO

Despite being a clinically approved intervention for cancer, photodynamic therapy (PDT) still suffers from limitations. Prime among these is a therapeutic response that is mostly oxygen dependent. This limits the utility of PDT in treating hypoxic tumors since lower levels of cytotoxic reactive oxygen species (ROS) are generated in regions of low oxygen tension. Glutathione-pi (GST-pi) is a key enzyme that militates against ROS-mediated apoptosis. We report here a new construct, EA-BPS, that contains both a brominated BODIPY photosensitizer (BPS) and an ethacrynic acid (EA) GST-pi inhibitor. Photoirradiation of EA-BPS induces a synergistic antitumor effect that results from the combination of ROS production and GST-pi inhibition. Relative to BPS alone, an enhanced cell-killing effect is seen under hypoxic conditions both in vitro and in vivo. We conclude that by making better use of the available oxygen in tumor environments, improved therapeutic PDT outcomes should be achievable even under hypoxic conditions.

18.
ACS Chem Neurosci ; 11(22): 3814-3822, 2020 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-33147004

RESUMO

Histidine tautomerism is considered a crucial component that affects the constitutional and accumulation characteristics of the tau267-312 monomer in the neutral condition, which are connected with the pathobiology of Alzheimer's disease (AD). Interpreting the organizational characteristics and accumulation procedure is a challenging task because two tautomeric conformations (the Nε-H or Nδ-H tautomer) can occur in the open neutral condition. In the current work, replica-exchange molecular dynamics (REMD) simulations were performed to investigate the structural properties of the tau267-312 monomer considering the histidine tautomeric effect. Based on the simulation outcomes, the histidine 268 (H268) (δ)-H299 (δ) (δδ) isomer had the highest ß-sheet content with a value of 26.2%, which acquires a sheet-governing toxic conformer with the first abundant conformational state of 22.6%. In addition, δδ displayed notable antiparallel ß-sheets between lysine 8 (K8)-asparagine 13 (N13) and valine 40 (V40)-tyrosine 44 (Y44) as well as between K32-H33 and V40-Y44 (ß-meander supersecondary structure), indicating this tautomeric isomer may exist to stimulate tau oligomerization. Furthermore, H299 was found to play an essential role in the structural stabilization of the δδ isomer compared with H268. The present research will aid in obtaining insight into the organizational and accumulation properties of tau protein in the presence of histidine tautomerism to control AD.

19.
Sci Rep ; 10(1): 13830, 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32778693

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

20.
Inorg Chem ; 59(17): 12471-12485, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32786395

RESUMO

To study the effect of a stable radical on the photophysical properties of a phosphorescent Pt(II) coordination framework and the intramolecular magnetic interaction between radical ligands in the N^N Pt(II) bisacetylide complexes, we prepared a series of N^N Pt(II) bis(acetylide) complexes with oxoverdazyl radical acetylide ligands. The linker between the Pt(II) center and the spin carrier was systematically varied, to probe the effect on the sign and magnitude of the spin exchange interactions between the radical ligands and photophysical properties. The complexes were studied with steady-state and femtosecond/nanosecond transient absorption spectroscopy, continuous-wave electron paramagnetic resonance (EPR) spectroscopy, and density functional theory (DFT) computations. The transient absorption spectral studies show that the doublet excited state of the radicals are short-lived (τD ≈ 2 ps) and nonfluorescent. Moreover, the intrinsic long-lived triplet excited state (τT = 1.2 µs) of the Pt(II) coordination center was efficiently quenched by the radical (τT = 6.9 ps for one representative radical Pt(II) complex). The intramolecular magnetic interaction between the radical ligands through the diamagnetic Pt(II) atom was studied with temperature-dependent EPR spectroscopy; antiferromagnetic exchange interaction (-J S1S2, J = -5.4 ± 0.1 cm-1) for the complex with the shortest radical-radical distance through bridge fragments was observed. DFT computations give similar results for the sign and magnitude of the J values. For complexes with larger inter-radical distance, however, very weak coupling between the radical ligands was observed (|J| < 0.7 cm-1). Our results are useful for the study of the effect of a radical on the photophysical properties of the phosphorescent transition-metal complexes.

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