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1.
J Org Chem ; 89(5): 3102-3110, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38364274

RESUMO

An approach to 2,3-benzotropone from 1-benzosuberone via palladium(II)-catalyzed aerobic dehydrogenation was developed. This method first provided a catalytic route to various 2,3-benzotropones from their corresponding 1-benzosuberones in good yields. In addition, the reaction could be applied to a one-pot Diels-Alder reaction with maleimide, providing a complex benzobicyclo[3.2.2]nonenone in ≤90% yield. Kinetic analysis supporting our proposed mechanism was also performed, underscoring the robustness of the developed synthetic pathway.

2.
Chem Biol Interact ; 391: 110903, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38331335

RESUMO

This study delves into the intricate mechanisms underlying drug-induced liver injury (DILI) with a specific focus on bromfenac, the withdrawn nonsteroidal anti-inflammatory drug. DILI is a pervasive concern in drug development, prompting market withdrawals and posing significant challenges to healthcare. Despite the withdrawal of bromfenac due to DILI, the exact role of its microsomal metabolism in inducing hepatotoxicity remains unclear. Herein, employing HepG2 cells with human liver microsomes and UDP-glucuronic acid (UDPGA), our investigation revealed a substantial increase in bromfenac-induced cytotoxicity in the presence of UDPGA, pointing to the significance of UDP-glucuronosyltransferase (UGT)-dependent metabolism in augmenting toxicity. Notably, among the recombinant UGTs examined, UGT2B7 emerged as a pivotal enzyme in the metabolic activation of bromfenac. Metabolite identification studies disclosed the formation of reactive intermediates, with bromfenac indolinone (lactam) identified as a potential mediator of hepatotoxic effects. Moreover, in cytotoxicity experiments, the toxicity of bromfenac lactam exhibited a 34-fold increase, relative to bromfenac. The toxicity of bromfenac lactam was mitigated by nicotinamide adenine dinucleotide phosphate-dependent metabolism. This finding underscores the role of UGT-dependent metabolism in generating reactive metabolites that contribute to the observed hepatotoxicity associated with bromfenac. Understanding these metabolic pathways and the involvement of specific enzymes, such as UGT2B7, provides crucial insights into the mechanisms of bromfenac-induced liver injury. In conclusion, this research sheds light on the metabolic intricacies leading to cytotoxicity induced by bromfenac, especially emphasizing the role of UGT-dependent metabolism and the formation of reactive intermediates like bromfenac lactam. These findings offer insight into the mechanistic basis of DILI and emphasize the importance of understanding metabolism-mediated toxicity.


Assuntos
Benzofenonas , Bromobenzenos , Doença Hepática Induzida por Substâncias e Drogas , Uridina Difosfato Ácido Glucurônico , Humanos , Uridina Difosfato Ácido Glucurônico/metabolismo , Uridina Difosfato Ácido Glucurônico/farmacologia , Microssomos Hepáticos/metabolismo , Glucuronosiltransferase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Lactamas/metabolismo , Lactamas/farmacologia , Glucuronídeos/metabolismo
3.
PLoS One ; 19(1): e0297057, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38241416

RESUMO

BACKGROUND: Recently, we developed a chest compression device that can move the chest compression position without interruption during CPR and be remotely controlled to minimize rescuer exposure to infectious diseases. The purpose of this study was to compare its performance with conventional mechanical CPR device in a mannequin and a swine model of cardiac arrest. MATERIALS AND METHODS: A prototype of a remote-controlled automatic chest compression device (ROSCER) that can change the chest compression position without interruption during CPR was developed, and its performance was compared with LUCAS 3 in a mannequin and a swine model of cardiac arrest. In a swine model of cardiac arrest, 16 male pigs were randomly assigned into the two groups, ROSCER CPR (n = 8) and LUCAS 3 CPR (n = 8), respectively. During 5 minutes of CPR, hemodynamic parameters including aortic pressure, right atrial pressure, coronary perfusion pressure, common carotid blood flow, and end-tidal carbon dioxide partial pressure were measured. RESULTS: In the compression performance test using a mannequin, compression depth, compression time, decompression time, and plateau time were almost equal between ROSCER and LUCAS 3. In a swine model of cardiac arrest, coronary perfusion pressure showed no difference between the two groups (p = 0.409). Systolic aortic pressure and carotid blood flow were higher in the LUCAS 3 group than in the ROSCER group during 5 minutes of CPR (p < 0.001, p = 0.008, respectively). End-tidal CO2 level of the ROSCER group was initially lower than that of the LUCAS 3 group, but was higher over time (p = 0.022). A Kaplan-Meier survival analysis for ROSC also showed no difference between the two groups (p = 0.46). CONCLUSION: The prototype of a remote-controlled automated chest compression device can move the chest compression position without interruption during CPR. In a mannequin and a swine model of cardiac arrest, the device showed no inferior performance to a conventional mechanical CPR device.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca , Masculino , Animais , Suínos , Projetos Piloto , Manequins , Parada Cardíaca/terapia , Pressão , Hemodinâmica
4.
Bioeng Transl Med ; 8(6): e10472, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38023714

RESUMO

Recent studies on osteosarcoma regimens have mainly focused on modifying the combination of antineoplastic agents rather than enhancing the therapeutic efficacy of each component. Here, an albumin nanocluster (NC)-assisted methotrexate (MTX), doxorubicin (DOX), and cisplatin (MAP) regimen with improved antitumor efficacy is presented. Human serum albumin (HSA) is decorated with thiamine pyrophosphate (TPP) to increase the affinity to the bone tumor microenvironment (TME). MTX or DOX (hydrophobic MAP components) is adsorbed to HSA-TPP via hydrophobic interactions. MTX- or DOX-adsorbed HSA-TPP NCs exhibit 20.8- and 1.64-fold higher binding affinity to hydroxyapatite, respectively, than corresponding HSA NCs, suggesting improved targeting ability to the bone TME via TPP decoration. A modified MAP regimen consisting of MTX- or DOX-adsorbed HSA-TPP NCs and free cisplatin displays a higher synergistic anticancer effect in HOS/MNNG human osteosarcoma cells than conventional MAP. TPP-decorated NCs show 1.53-fold higher tumor accumulation than unmodified NCs in an orthotopic osteosarcoma mouse model, indicating increased bone tumor distribution. As a result, the modified regimen more significantly suppresses tumor growth in vivo than solution-based conventional MAP, suggesting that HSA-TPP NC-assisted MAP may be a promising strategy for osteosarcoma treatment.

5.
Org Lett ; 25(19): 3471-3475, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37140886

RESUMO

A novel persulfate-mediated oxidative glycosylation system using p-methoxyphenyl (PMP) glycosides as bench-stable glycosyl donors is developed. This study shows that both K2S2O8 as an oxidant and Hf(OTf)4 as a Lewis acid catalyst play important roles in the oxidative activation of the PMP group into a potential leaving group. This convenient glycosylation protocol proceeds under mild conditions and delivers a wide range of biologically and synthetically valuable glycoconjugates, including glycosyl fluorides.

6.
J Org Chem ; 87(5): 2640-2650, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-35020397

RESUMO

The three-component alkylfluorination of olefins via an oxidative radical-polar crossover under visible light-induced photocatalysis is disclosed. A key feature of this reaction is the incorporation of two synthetically meaningful components involving a three-dimensional alkyl group and a fluorine atom using easily preparable N-hydroxyphthalimide esters as the alkyl donors and a low-cost hydrogen fluoride as the fluorine source. Furthermore, a one-step procedure using commercially available carboxylic acids demonstrated the versatility of this new method.


Assuntos
Alcenos , Flúor , Catálise , Estrutura Molecular , Estresse Oxidativo
7.
Prep Biochem Biotechnol ; 52(2): 144-153, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33950798

RESUMO

Ginseng flower bud (GFB), as an inexpensive part of Panax ginseng, attracted significant attention as a beneficial functional food with medicinal potentials due to its high content of ginsenosides. A few studies focused on the utilization of heat treatment and citric acid treatment to process ginseng flowers, converting its polar ginsenosides into rare ginsenosides to improve its biological activities. Thus, in this study, we compared the changes of ginsenosides in GFB after citric acid and heat treatment by HPLC method. The results revealed that less-polar ginsenoside, Rg6 and F4, increased to 1.01 and 0.27% by heat treatment, respectively. Further, ginsenoside F2 increased to 1.13% with 1 M citric acid treatment. Furthermore, based on the combination of these two processing methods for the first time, the conversion rate of less-polar ginsenosides surged to 80%. The content of ginsenoside Rg3(s) and Rg5 increased to 1.509 and 1.871%, respectively, by simultaneous heat and citric acid treatment. Therefore, a processing approach that simultaneously performs heat and citric acid treatments has been proposed, and this considerably inexpensive and convenient processing method could be applied to the processing of GFBs and produce less-polar ginsenosides.


Assuntos
Ácido Cítrico/farmacologia , Flores/metabolismo , Ginsenosídeos/metabolismo , Temperatura Alta , Panax/metabolismo , Cromatografia Líquida de Alta Pressão
8.
Molecules ; 26(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34641481

RESUMO

Pladienolides, an emerging class of naturally occurring spliceosome modulators, exhibit interesting structural features, such as highly substituted 12-membered macrocycles and epoxide-containing diene side chains. The potential of pladienolides as anti-cancer agents is confirmed by H3B-8800, a synthetic analog of this natural product class, which is currently under Phase I clinical trials. Since its isolation in 2004 and the first total synthesis in 2007, a dozen total syntheses and synthetic approaches toward the pladienolide class have been reported to date. This review focuses on the eight completed total syntheses of naturally occurring pladienolides or their synthetic analogs, in addition to a synthetic approach to the main framework of the natural product.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Produtos Biológicos/farmacologia , Compostos de Epóxi/farmacologia , Macrolídeos/farmacologia , Neoplasias/tratamento farmacológico , Spliceossomos/efeitos dos fármacos , Animais , Humanos , Neoplasias/patologia
9.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360871

RESUMO

The root of Pueraria lobata (Willd.) is a widely used herbal medicine worldwide, whereas the stem of the plant is discarded or used as feed for livestock. To reuse and exploit the stem of P. lobata as a resource, we investigated its potential as a skin-whitening agent. We found that the developed, enriched P. lobata stem (PLS) extract significantly inhibited melanin production in the 3-isobutyl-1-methylxanthine-induced B16/F10 cells at a concentration of 50 µg/mL. To further confirm the mechanism of the antimelanogenic effect of the enriched PLS extracts, we examined the mRNA expression of tyrosinase, which was suppressed by the extracts. To standardize and implement effective quality control of the enriched PLS extracts, its major chemical constituents were identified by high-performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry. In total, 12 constituents were identified. In silico analysis showed that the main constituents, puerarin and daidzin, had excellent binding affinities for human tyrosinase. Collectively, our results suggest that the PLS extracts could be used as anti-pigmentation agents.


Assuntos
Melaninas/biossíntese , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Caules de Planta/química , Pueraria/química , Preparações Clareadoras de Pele/farmacologia , Linhagem Celular Tumoral , Humanos , Isoflavonas/farmacologia , Melanoma Experimental , Monofenol Mono-Oxigenase/metabolismo
10.
Int J Mol Sci ; 22(5)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803380

RESUMO

γ-Butyrolactone, a five-membered lactone moiety, is one of the privileged structures of diverse natural products and biologically active small molecules. Because of their broad spectrum of biological and pharmacological activities, synthetic methods for γ-butyrolactones have received significant attention from synthetic and medicinal chemists for decades. Recently, new developments and improvements in traditional methods have been reported by considering synthetic efficiency, feasibility, and green chemistry. In this review, the pharmacological activities of natural and synthetic γ-butyrolactones are described, including their structures and bioassay methods. Mainly, we summarize recent advances, occurring during the past decade, in the construction of γ-butyrolactone classified based on the bond formation in γ-butyrolactone between (i) C5-O1 bond, (ii) C4-C5 and C2-O1 bonds, (iii) C3-C4 and C2-O1 bonds, (iv) C3-C4 and C5-O1 bonds, (v) C2-C3 and C2-O1 bonds, (vi) C3-C4 bond, and (vii) C2-O1 bond. In addition, the application to the total synthesis of natural products bearing γ-butyrolactone scaffolds is described.


Assuntos
4-Butirolactona/química , 4-Butirolactona/síntese química , 4-Butirolactona/farmacologia , Animais , Química Verde , Humanos , Estrutura Molecular
11.
Eur J Med Chem ; 216: 113318, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33730624

RESUMO

Identifying a pharmacological agent that targets only one of more than 500 kinases present in humans is an important challenge. One potential solution to this problem is the development of bivalent kinase inhibitors, which consist of two connected fragments, each bind to a dissimilar binding site of the bisubstrate enzyme. The main advantage of bivalent (type V) kinase inhibitors is generating more interactions with target enzymes that can enhance the molecules' selectivity and affinity compared to single-site inhibitors. Earlier type V inhibitors were not suitable for the cellular environment and were mostly used in in vitro studies. However, recently developed bivalent compounds have high kinase affinity, high biological and chemical stability in vivo. This review summarized the hetero-bivalent kinase inhibitors described in the literature from 2014 to the present. We attempted to classify the molecules by serine/threonine and tyrosine kinase inhibitors, and then each target kinase and its hetero-bivalent inhibitor was assessed in depth. In addition, we discussed the analysis of advantages, limitations, and perspectives of bivalent kinase inhibitors compared with the monovalent kinase inhibitors.


Assuntos
Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Receptor EphA1/antagonistas & inibidores , Receptor EphA1/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
12.
J Org Chem ; 85(21): 13779-13792, 2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33049140

RESUMO

A collective synthetic route for tricyclic guaiane sesquiterpenes and total syntheses of (+)-dysodensiol F, (+)-10ß,14-dihydroxy-allo-aromadendrane, and (-)-dendroside C aglycon starting from a versatile hydroazulene intermediate were accomplished. The key features of these syntheses involve late-stage carbene-mediated diastereoselective cyclopropanation, construction of an unusual cis-fused-hydroazulene skeleton via intramolecular Dieckmann condensation, and highly stereoselective tandem conjugate addition/intramolecular allylic alkylation to afford a 5/7/3 tricyclic skeleton of guaiane natural products. The synthesis of (-)-dendroside C aglycon and the first total synthesis of (+)-dysodensiol F and (+)-10ß,14-dihydroxy-allo-aromadendrane are described in detail. Activation of the Nrf2/ARE signaling pathway by (-)-dendroside C aglycon is also disclosed via our synthesis.

13.
Medicine (Baltimore) ; 99(37): e22123, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32925762

RESUMO

RATIONALE: Peroneal neuropathy is the most common type of peripheral neuropathy in the lower extremities. The peroneal nerve is usually compressed at the lateral aspect of the fibular head. Compression by ganglion cysts are one of the numerous underlying etiologies for peroneal nerve neuropathy and are most frequently located around the fibular neck and proximal tibiofibular joint. To the best of our knowledge, this is the first report of an extraneural ganglion cyst located at the level of the distal thigh that resulted in compressive peroneal neuropathy. PATIENT CONCERNS: We report a case of a 56-year-old man with sudden onset of left foot drop and gait disturbance caused by an extraneural ganglion cyst located in the popliteal fossa. DIAGNOSIS: Electrodiagnosis (EDX) suggested a peroneal nerve lesion. Subsequently, diagnostic ultrasonography (USG) revealed a cystic mass located within the left side of the supracondylar area of femur. Further magnetic resonance imaging confirmed that the mass was located at the proximal of popliteal fossa. INTERVENTIONS: Surgical excision was performed using a direct posterior approach. The cystic mass was compressing the common peroneal nerve, and was carefully and completely removed ensuring that all nerve branches were protected. OUTCOMES: A histopathologic evaluation confirmed the diagnosis of a ganglion cyst. There were no postoperative complications. Two months after the surgery, follow-up USG revealed no evidence of cyst recurrence or residual lesions. Six months after the surgery, the ankle dorsiflexor motor power improved and he experienced less pain and hypoesthesia. LESSONS: Physicians should bear in mind that the peroneal neuropathy can occur because of the ganglion cyst in the distal thigh. The thorough evaluation of EDX and USG is crucial for the early diagnosis and surgical intervention, although there is no abnormal finding around the fibular neck.


Assuntos
Cistos Ósseos/complicações , Cistos Ósseos/diagnóstico , Fêmur , Cistos Glanglionares/complicações , Cistos Glanglionares/diagnóstico , Neuropatias Fibulares/etiologia , Cistos Ósseos/cirurgia , Cistos Glanglionares/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade
14.
Ann Rehabil Med ; 44(3): 181-194, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32475098

RESUMO

OBJECTIVE: To investigate the usefulness of goal attainment scaling (GAS) in intensive stroke rehabilitation during the subacute stage. METHODS: Medical records of subacute post-stroke patients who had undergone intensive rehabilitation under hospitalization, before and after the application of GAS, were collected. GAS was conducted at the initial evaluation of each patient. Specific goals were suggested by physical and occupational therapists and were determined by the responsible physiatrist. A 5-point scale was used for the GAS score after 4 weeks of rehabilitation according to the preset criteria of each goal. To evaluate the influence of GAS in rehabilitation practice, functional improvements were compared between two patient groups before (n=121) and after (n=141) GAS. To assess progress in GAS practice, the standard GAS score was calculated, and the changes were observed over a 3-year period. The standard GAS score converged to 50 points when the goal was achieved. The therapists who used GAS also completed a survey regarding its usefulness. RESULTS: There were no statistical differences in the motor and cognitive outcomes of the patient groups before and after applying GAS scoring. Successive yearly changes in the standard GAS scores showed progressive convergence to 50 points, signaling that the patient's goal-setting abilities improved. According to the survey, most therapists felt that GAS enhanced the quality of therapies (84.6%). CONCLUSION: GAS improved goal-setting for the rehabilitation of subacute post-stroke patients and might have a positive effect on rehabilitation.

15.
Molecules ; 25(8)2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32340245

RESUMO

A concise and scalable synthetic route for optically pure (4S) and (4R)-5-(3',4'-dihydroxyphenyl)-γ-valerolactones (DHPVs), catechin metabolites, has been developed via the efficient construction of a γ-valerolactone moiety from hexenol. Noticeably, the different skin wrinkle-reducing activities of each metabolite were revealed via our unique syntheses of DHPVs in an enantiomerically pure form.


Assuntos
Catequina/síntese química , Catequina/farmacologia , Lactonas/síntese química , Lactonas/farmacologia , Pele/efeitos dos fármacos , Humanos , Estrutura Molecular , Oxirredução , Envelhecimento da Pele/efeitos dos fármacos
16.
J Phys Condens Matter ; 32(24): 245501, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32079011

RESUMO

A new first-principles computation scheme to calculate 'branching ratio' has been applied to various 5d, 4d, and 3d transition metal elements and compounds. This recently suggested method is based on a theory which assumes the atomic core hole interacts barely with valence electrons. While it provides an efficient way to calculate the experimentally measurable quantity without generating spectrum itself, its reliability and applicability should be carefully examined especially for the light transition metal systems. Here we select 36 different materials and compare the calculation results with experimental data. It is found that our scheme well describes 5d and 4d transition metal systems whereas, for 3d materials, the difference between the calculation and experiment is quite significant. It is attributed to the neglect of core-valence interaction whose energy scale is comparable with the spin-orbit coupling of core p orbitals.

17.
Org Lett ; 22(3): 1046-1051, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-31940210

RESUMO

DNA-encoded library (DEL) technology has emerged as a novel interrogation modality for ligand discovery in the pharmaceutical industry. Given the increasing demand for a higher proportion of C(sp3)-hybridized centers in DEL platforms, a photoredox-mediated cross-coupling and defluorinative alkylation process is introduced using commercially available alkyl bromides and structurally diverse α-silylamines. Notably, no protecting group strategies for amines are necessary for the incorporation of a variety of amino-acid-based organosilanes, providing crucial branching points for further derivatization.


Assuntos
Aminas/síntese química , DNA/química , Hidrocarbonetos Bromados/química , Alquilação , Aminas/química , Estrutura Molecular , Oxirredução , Processos Fotoquímicos , Estereoisomerismo
18.
Front Neurol ; 10: 1264, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31866926

RESUMO

Objectives: The purposes of this study are to determine whether there is a correlation between the Mann Assessment of Swallowing Ability (MASA) and modified MASA (mMASA) according to various cognitive status and to investigate whether the cognitive status of patients with brain damage affects the prediction of aspiration using the MASA. Methods: We retrospectively assessed 146 dysphagic patients with brain lesion due to various causes. Dysphagia was assessed using the MASA and mMASA. According to the videofluoroscopic swallowing study results, patients were divided into two groups: aspirators and non-aspirators. Patients were classified into four groups according to cognitive function according to the Korean version of Mini-mental State Examination scores: normal (>24), mild (21-24), moderate (10-20), and severe (<10) cognitive impairment. The correlation between the MASA and mMASA scores according to cognitive function were analyzed. The sensitivity, specificity, and positive and negative predictive values of the MASA scores for predicting aspiration were assessed. Results: The MASA and mMASA scores showed a significant positive correlation in all cognition groups. In patients with more severe cognitive impairment MASA scores had high sensitivity and low specificity for prediction of aspiration. On the other hand, the MASA scores had low sensitivity and high specificity for prediction of aspiration in the normal and mild cognitive impairment groups. Conclusions: The MASA and mMASA scores correlated with each other in patients with various levels of cognitive function. Interestingly, this study results demonstrated that patients with good cognitive function may have false negative results of MASA screening due to low sensitivity. Thus, when interpreting the MASA results, the impact of cognitive status should be taken into consideration.

19.
ACS Catal ; 9(2): 1558-1563, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31588366

RESUMO

A mild, metal-free, regioselective carbofluorination of dehydroalanine derivatives has been developed. Alkyl radicals resulting from visible-light photoredox catalysis engage in a radical conjugate addition to dehydroalanine, with subsequent fluorination of the newly generated radical to afford an α-fluoro-α-amino acid. By using a highly oxidizing organic photocatalyst, this process incorporates non-stabilized primary, secondary, and tertiary alkyl radicals derived from commercially available alkyltrifluoroborates to furnish a wide range of fluorinated unnatural amino acids.

20.
J Phys Condens Matter ; 31(40): 405503, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31220821

RESUMO

We report a successful combination of magnetic force linear response theory with quasiparticle self-consistent GW method. The self-consistently determined wavefunctions and eigenvalues can just be used for the conventional magnetic force calculations. While its formulation is straightforward, this combination provides a way to investigate the effect of GW self-energy on the magnetic interactions which can hardly be quantified due to the limitation of current GW methodology in calculating the total energy difference in between different magnetic phases. In ferromagnetic 3d elements, GW self-energy slightly reduces the d bandwidth and enhances the interactions while the same long-range feature is maintained. In antiferromagnetic transition-metal monoxides, QSGW significantly reduces the interaction strengths by enlarging the gap. Orbital-dependent magnetic force calculations show that the coupling between e g and the nominally-empty 4s orbital is noticeably large in MnO which is reminiscent of the discussion for cuprates regarding the role of Cu-4s state. This combination of magnetic force theory with quasiparticle self-consistent GW can be a useful tool to study various magnetic materials.

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