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1.
J Am Chem Soc ; 146(6): 3622-3626, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38306245

RESUMO

A versatile synthetic strategy for the preparation of homo- and heterobimetallic complexes bearing an unprecedented mesoionic Janus-type diNHC is presented. Moreover, its electronic property is evaluated, and a preliminary catalytic application in the direct diarylation of 1-methylpyrrole is demonstrated.

2.
Chemistry ; 30(51): e202402127, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-38953274

RESUMO

The preparations of homo- and hetero-bimetallic complexes as well as thiourea and selenourea derivatives of a mesoionic Janus-type N-heterocyclic dicarbene (diNHC) are reported. Analogues of its monocationic intermediate NHC have also been obtained for comparison. Using the main group adducts, the π-acceptor properties of both NHCs were determined using low temperature 77Se NMR spectroscopy completing their stereoelectronic profiling. Moreover, catalytic investigations reveal that the mesoionic dipalladium Janus-diNHC complex can be used in the sequential C2- and C5-arylation of 1-methylpyrrole for the preparation of non-symmetrical 2,5-diarylpyrroles.

3.
Inorg Chem ; 63(39): 18242-18250, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39285687

RESUMO

The electronic properties of eight Buchwald-type phosphines were determined and ranked by 13C NMR spectroscopy, highlighting the sensitivity of the Huynh electronic parameter (HEP). Furthermore, the 13Ccarbene NMR signals of 19 known and new P-donor complexes in CDCl3 (HEP values) are found to be highly correlated to those in C6D6. This enables the donor strength determination of P-donors even where the complexes are unstable or undergo rapid isomerization due to transphobia in CDCl3.

4.
Inorg Chem ; 63(9): 4344-4354, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38387056

RESUMO

A detailed electronic study of the N-phosphine oxide functionalized imidazolin-2-ylidenes (PoxIms) and imidazolidin-2-ylidenes (SPoxIms) has been performed experimentally using IR, 13C, and 77Se NMR spectroscopies. While the net donor/acceptor properties of the (S)PoxIms could not be differentiated via IR spectroscopy (TEP), NMR spectroscopic methods (HEP, Se) reveal that the (S)PoxIms are slightly weaker σ-donors but stronger π-acceptors compared to common NHCs. Moreover, backbone and substituent-effects could also be resolved by the latter, allowing for a ranking of their electronic properties. Finally, the donicities of these well-designed NHC ligands in their bidentate κ2-C,O modes were evaluated using HEP2 and compared to those of classical chelators.

5.
Inorg Chem ; 63(18): 8286-8293, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38641432

RESUMO

Multi-interpenetrated metal-organic frameworks (MOFs) have exhibited excellent performance in selective adsorption due to the variable post-interspersed flexibility, but the design and control remain challenging. Herein, two anthracene-based ligands, 4,4'-(anthracene-9,10-diyl)dibenzoic acid (H2L1) and 9,10-di(pyridin-4-yl)anthracene (L2), are used to construct a new three-dimensional 6-fold interpenetrated MOF [Zn(L1)(L2)]n (NBU-X1), which exhibits multiple C-H···π interactions that enhance the structural rigidity, thereby entangling with a C2H2/C2H4 separation performance. In this material, the incorporation of abundant anthracene rings within the framework not only partitions and restricts the pore window size to a quasi-double pore but also stabilizes it through host-host interactions. The structural stability upon heating or guest displacement/removal has been investigated by single-crystal X-ray diffraction and in situ variable-temperature powder X-ray diffraction, in contrast to the extreme flexibility of most multi-interpenetrated MOFs. The performance of purifying C2H4 from C2H2/C2H4 mixtures has been proved by dynamic breakthrough tests.

6.
Inorg Chem ; 63(14): 6116-6121, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38518373

RESUMO

Obtaining compounds with large nonlinear-optical (NLO) coefficients and wide band gaps is challenging due to their competitive requirements for chemical bonds. Herein, the first member with mixed cations on the A site in the A-M3-Q5 or A-Ag-M6-Q10 (A = alkali metal; M = Ga, In; Q = S, Se, Te) family, viz. Na0.45Ag0.55Ga3Se5 (NAGSe), was obtained by a solid-state reaction. Its structure features [GaSe4] tetrahedra built three-dimensional {[Ga3Se5]-}∞ network, with Na and Na/Ag cations located at the octahedral cavities. Noncentrosymmetric (R32) NAGSe can also be transformed from centrosymmetric RbGa3S5 (P21/c) via multiple-site cosubstitution. NAGSe exhibits the highest NLO response (1.9 × AGS) in the A-Ag-M-Q family. Crystal structure analysis and theoretical calculations suggest that the NLO response is mainly contributed by the regularly arranged [GaSe4] units. This work enriches the exploration of the undeveloped A-M3-Q5 or A-Ag-M6-Q10 family as potential infrared NLO materials.

7.
Biochem Genet ; 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38877158

RESUMO

Endophytic fungi associated with plants may contain undiscovered bioactive compounds. Under standard laboratory conditions, most undiscovered compounds are inactive, whereas their production could be stimulated under different cultivation conditions. In this study, six endophytic fungi were isolated from the bark of Koelreuteria paniculata in Quancheng Park, Jinan City, Shandong Province, one of which was identified as a new subspecies of Aureobasidium pullulans, named A. pullulans KB3. Additionally, metabolomic tools were used to screen suitable media for A. pullulans KB3 fermentation, and the results showed that peptone dextrose medium (PDM) was more beneficial to culture A. pullulans KB3 for isolation of novel compounds. Sphaerolone, a polyketone compound, was initially isolated from A. pullulans KB3 via scaled up fermentation utilizing PDM. Additionally, the whole-genome DNA of A. pullulans KB3 was sequenced to facilitate compound isolation and identify the biosynthesis gene clusters (BGCs). This study reports the multi-omics (metabolome and genome) analysis of A. pullulans KB3, laying the foundation for discovering novel compounds of silent BGCs and identifying their biosynthesis pathway.

8.
Sensors (Basel) ; 24(17)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39275425

RESUMO

Ensuring safety in autonomous driving is crucial for effective motion planning and navigation. However, most end-to-end planning methodologies lack sufficient safety measures. This study tackles this issue by formulating the control optimization problem in autonomous driving as Constrained Markov Decision Processes (CMDPs). We introduce an innovative, model-based approach for policy optimization, employing a conditional Value-at-Risk (VaR)-based soft actor-critic (SAC) to handle constraints in complex, high-dimensional state spaces. Our method features a worst-case actor to ensure strict compliance with safety requirements, even in unpredictable scenarios. The policy optimization leverages the augmented Lagrangian method and leverages latent diffusion models to forecast and simulate future trajectories. This dual strategy ensures safe navigation through environments and enhances policy performance by incorporating distribution modeling to address environmental uncertainties. Empirical evaluations conducted in both simulated and real environments demonstrate that our approach surpasses existing methods in terms of safety, efficiency, and decision-making capabilities.

9.
Zhongguo Zhong Yao Za Zhi ; 49(5): 1225-1239, 2024 Mar.
Artigo em Zh | MEDLINE | ID: mdl-38621969

RESUMO

Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was employed to investigate the impacts of Pruni Semen processed with different methods(raw and fried) on the liver and spleen metabolism in mice. A total of 24 male mice were randomly assigned to three groups: raw Pruni Semen group, fried Pruni Semen group, and control(deionized water) group. Mice in the three groups were orally administrated with 0.01 g·mL~(-1) Pruni Semen decoction or deionized water for one week. After that, the liver and spleen tissues were collected, and liquid chromatography-mass spectrometry(LC-MS)-based metabolomic analysis was carried out to investigate the impact of Pruni Semen on the liver and spleen metabolism in mice. Compared with thte control group, the raw Pruni Semen group showed up-regulation of 11 metabolites and down-regulation of 57 metabolites in the spleen(P<0.05), as well as up-regulation of 15 metabolites and down-regulation of 58 metabolites in the liver(P<0.05). The fried Pruni Semen group showed up-regulation of 31 metabolites and down-regulation of 10 metabolites in the spleen(P<0.05), along with up-regulation of 26 metabolites and down-regulation of 61 metabolites in the liver(P<0.05). The differential metabolites identified in the raw Pruni Semen group were primarily associated with alanine, aspartate, and glutamate metabolism, purine metabolism, amino sugar and nucleotide sugar metabolism, and D-glutamine and D-glutamate metabolism. The differential metabolites identified in the fried Pruni Semen group predominantly involved riboflavin metabolism, amino sugar and nucleotide sugar metabolism, purine metabolism, alanine, aspartate, and glutamate metabolism, D-glutamine and D-glutamate metabolism, and glutathione metabolism. The findings suggest that both raw and fried Pruni Semen have the potential to modulate the metabolism of the liver and spleen in mice by influencing the glutamine and glutamate metabolism.


Assuntos
Ácido Glutâmico , Baço , Camundongos , Masculino , Animais , Sêmen , Glutamina , Ácido Aspártico , Metabolômica/métodos , Fígado/metabolismo , Alanina/metabolismo , Amino Açúcares/metabolismo , Água/metabolismo , Nucleotídeos/metabolismo , Purinas/metabolismo , Açúcares , Cromatografia Líquida de Alta Pressão , Biomarcadores/metabolismo
10.
Inorg Chem ; 62(1): 295-303, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36563313

RESUMO

A library of 12 palladium(II) complexes of the type [PdBr(iPr2-bimy)(L∧X)] comprising 10 dithiocarbamato (R2NCS2-) and two xanthato (ROCS2-) ligands have been prepared and fully characterized. With these complexes in hand, the electronic and steric properties of the bidentate, monoanionic ligands were evaluated using the HEP2 and %Vbur methodologies. Moreover, the construction of the first stereoelectronic map for dithiocarbamates enabled the in-principle identification of optimal ligand parameters for enhanced cytotoxic activities of their gold(III) complexes. This application of the stereoelectronic map showcases its viability as a useful tool to establish structure-activity relationships for rational ligand design.


Assuntos
Antineoplásicos , Ligantes , Relação Estrutura-Atividade , Antineoplásicos/farmacologia , Ouro , Paládio
11.
Inorg Chem ; 62(34): 13902-13909, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37572060

RESUMO

14 new gold(I) NHC complexes of the type [AuX(iPr2-bimy)] (iPr2-bimy = 1,3-diisopropylbenzimidazolin-2-ylidene) have been prepared and fully characterized. These complexes and their reported analogues were used to systematically compare and rank the donating abilities of overall 34 anionic X-type donors by 13C NMR spectroscopy. Specifically, the carbene chemical shift of the iPr2-bimy ligand was found to be responsive to the ligand X spanning an overall range Δδ > 37 ppm between the strongest and weakest donor in this study.

12.
Inorg Chem ; 62(11): 4606-4617, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36872911

RESUMO

14 mono-, di-, and tetranuclear palladium complexes were prepared to study the coordination chemistry of symmetrical and unsymmetrical azole-derived diimines and their anions. The diverse range of complexes obtained highlights the structural and electronic diversities imposed by these ligands. Using the monopalladium species, the electronic properties of selected bidentate ligands were determined, ranked, and compared by 13C NMR spectroscopy, extending the scope of the HEP2 (Huynh electronic parameter 2) scale, which can detect even subtle differences. Moreover, the %Vbur (percentage volume buried) values as an estimate for the steric bulk of some ligands were determined using the solid-state molecular structures of their complexes, and a preliminary stereoelectronic map was established.

13.
Brain ; 145(1): 305-323, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35022692

RESUMO

Mitochondrial defects are a hallmark of early pathophysiology in Alzheimer's disease, with pathologically phosphorylated tau reported to induce mitochondrial toxicity. Mitophagy constitutes a key pathway in mitochondrial quality control by which damaged mitochondria are targeted for autophagy. However, few details are known regarding the intersection of mitophagy and pathologies in tauopathy. Here, by applying biochemical and cell biological approaches including time-lapse confocal imaging in live tauopathy neurons, combined with gene rescue experiments via stereotactic injections of adeno-associated virus particles into tauopathy mouse brains, electrophysiological recordings and behavioural tests, we demonstrate for the first time that mitochondrial distribution deficits at presynaptic terminals are an early pathological feature in tauopathy brains. Furthermore, Parkin-mediated mitophagy is extensively activated in tauopathy neurons, which accelerates mitochondrial Rho GTPase 1 (Miro1) turnover and consequently halts Miro1-mediated mitochondrial anterograde movement towards synaptic terminals. As a result, mitochondrial supply at tauopathy synapses is disrupted, impairing synaptic function. Strikingly, increasing Miro1 levels restores the synaptic mitochondrial population by enhancing mitochondrial anterograde movement and thus reverses tauopathy-associated synaptic failure. In tauopathy mouse brains, overexpression of Miro1 markedly elevates synaptic distribution of mitochondria and protects against synaptic damage and neurodegeneration, thereby counteracting impairments in learning and memory as well as synaptic plasticity. Taken together, our study reveals that activation of the Parkin pathway triggers an unexpected effect-depletion of mitochondria from synaptic terminals, a characteristic feature of early tauopathy. We further provide new mechanistic insights into how parkin activation-enhanced Miro1 degradation and impaired mitochondrial anterograde transport drive tauopathy-linked synaptic pathogenesis and establish a foundation for future investigations into new therapeutic strategies to prevent synaptic deterioration in Alzheimer's disease and other tauopathies.


Assuntos
Doença de Alzheimer , Mitofagia , Doença de Alzheimer/metabolismo , Animais , Humanos , Camundongos , Mitocôndrias/metabolismo , Mitofagia/genética , Neurônios/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
14.
Inorg Chem ; 61(14): 5479-5483, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35344370

RESUMO

Second-order nonlinear optical (NLO) materials are extensively applied in laser-related techniques. For developing IR NLO materials, chalcogenides are the main candidates. Here, NaGa3Se5 was explored as inspired by its unique anionic structure. It crystallizes with the orthorhombic chiral P212121 structure, featuring 12 types of GaSe4 tetrahedra built into a three-dimensional {[Ga3Se5]-}∞ anionic network, representing a new NLO-functional motif. NaGa3Se5 exhibits large and phase-matchable NLO response 1.37 × AgGaS2. It has the largest band gap among the noncentrosymmetric A-MIII-Se (A = alkali metal; M = Ga, In) compounds. The NLO properties' origin is explored via theoretical analysis. The success of NaGa3Se5 contributes a practical case for exploring new NLO materials.

15.
CNS Spectr ; : 1-22, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33706820

RESUMO

Cognitive impairment is common in bipolar disorder and is emerging as a therapeutic target to enhance quality of life and function. A systematic search was conducted on PubMed, PsycInfo, Cochrane, clinicaltrials.gov, and Embase databases for blinded or open-label randomized controlled trials evaluating the pro-cognitive effects of pharmacological, neurostimulation, or psychological interventions for bipolar disorder. Twenty-two trials were identified, evaluating a total of 16 different pro-cognitive interventions. The methodological quality of the identified trials were assessed using the Cochrane Risk of Bias tool. Currently, no intervention (i.e., pharmacologic, neurostimulation, cognitive remediation) has demonstrated robust and independent pro-cognitive effects in adults with bipolar disorder. Findings are preliminary and methodological limitations limit the interpretation of results. Methodological considerations including, but not limited to, the enrichment with populations with pre-treatment cognitive impairment, as well as the inclusion of individuals who are in remission are encouraged. Future trials may also consider targeting interventions to specific cognitive subgroups and the use of biomarkers of cognitive function.

16.
Chemistry ; 25(61): 13956-13963, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31414703

RESUMO

The suitability and accuracy of the Huynh electronic parameter (HEP) was further tested to reveal remote substituent effects in pyridines, which are located five or six bonds away from the reporter probe. These values show an excellent correlation to Hammett σ-constants of the respective substituents with coefficients of R2 =0.9856 (σm ) and R2 =0.9857 (σp ). Based on this observation, a methodology for the re-evaluation of certain Hammett constants with larger uncertainties has been proposed and demonstrated. Moreover, the scope of HEP was extended to various neutral pnictogen and chalcogen donors during which "transphobia effects" were revealed for mixed NHC complexes containing phosphites, arsine and stibine for the first time.

17.
Med Rev (2021) ; 4(4): 312-325, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39135602

RESUMO

Incretins are gut-produced peptide-hormones that potentiate insulin secretion, especially after food intake. The concept of incretin was formed more than 100 years ago, even before insulin was isolated and utilized in the treatment of subjects with type 1 diabetes. The first incretin, glucose-dependent insulinotropic polypeptide (GIP), was identified during later 1960's and early 1970's; while the second one, known as glucagon-like peptide-1 (GLP-1), was recognized during 1980's. Today, GLP-1-based therapeutic agents [also known as GLP-1 receptor (GLP-1R) agonists, GLP-1RAs] are among the first line drugs for type 2 diabetes. In addition to serving as incretin, extra-pancreatic functions of GLP-1RAs have been broadly recognized, including those in the liver, despite the absence of GLP-1R in hepatic tissue. The existence of insulin-independent or gut-pancreas-liver axis-independent hepatic function of GLP-1RAs explains why those therapeutic agents are effective in subjects with insulin resistance and their profound effect on lipid homeostasis. Following a brief review on the discovery of GLP-1, we reviewed literature on the exploration of hepatic function of GLP-1 and GLP-1RAs and discussed recent studies on the role of hepatic hormone fibroblast growth factor 21 (FGF21) in mediating function of GLP-1RAs in animal models. This was followed by presenting our perspective views.

18.
Autophagy ; : 1-26, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39171695

RESUMO

Hyperphosphorylation and aggregation of MAPT (microtubule-associated protein tau) is a pathogenic hallmark of tauopathies and a defining feature of Alzheimer disease (AD). Pathological MAPT/tau is targeted by macroautophagy/autophagy for clearance after being sequestered within autophagosomes, but autophagy dysfunction is indicated in tauopathy. While mitochondrial bioenergetic deficits have been shown to precede MAPT/tau pathology in tauopathy brains, it is unclear whether energy metabolism deficiency is involved in the pathogenesis of autophagy defects. Here, we reveal that stimulation of anaplerotic metabolism restores defective oxidative phosphorylation (OXPHOS) in tauopathy neurons which, strikingly, leads to pronounced MAPT/tau clearance by boosting autophagy functionality through enhancements of mitochondrial biosynthesis and supply of phosphatidylethanolamine for autophagosome biogenesis. Furthermore, early anaplerotic stimulation of OXPHOS elevates autophagy activity and attenuates MAPT/tau pathology, thereby counteracting memory impairment in tauopathy mice. Taken together, our study sheds light on a pivotal role of mitochondrial bioenergetic deficiency in tauopathy-related autophagy defects and suggests a new therapeutic strategy to prevent the buildup of pathological MAPT/tau in AD and other tauopathy diseases.Abbreviation: AA: antimycin A; AD, Alzheimer disease; ATP, adenosine triphosphate; AV, autophagosome/autophagic vacuole; AZ, active zone; Baf-A1: bafilomycin A1; CHX, cycloheximide; COX, cytochrome c oxidase; DIV, days in vitro; DRG, dorsal root ganglion; ETN, ethanolamine; FRET, Förster/fluorescence resonance energy transfer; FTD, frontotemporal dementia; Gln, glutamine; HA: hydroxylamine; HsMAPT/Tau, human MAPT; IMM, inner mitochondrial membrane; LAMP1, lysosomal-associated membrane protein 1; LIs, lysosomal inhibitors; MDAV, mitochondria-derived autophagic vacuole; MmMAPT/Tau, murine MAPT; NFT, neurofibrillary tangle; OCR, oxygen consumption rate; Omy: oligomycin; OXPHOS, oxidative phosphorylation; PPARGC1A/PGC-1alpha: peroxisome proliferative activated receptor, gamma, coactivator 1 alpha; PE, phosphatidylethanolamine; phospho-MAPT/tau, hyperphosphorylated MAPT; PS, phosphatidylserine; PISD, phosphatidylserine decarboxylase;SQSTM1/p62, sequestosome 1; STX1, syntaxin 1; SYP, synaptophysin; Tg, transgenic; TCA, tricarboxylic acid; TEM, transmission electron microscopy.

19.
bioRxiv ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38405759

RESUMO

Hyperphosphorylation and aggregation of microtubule-associated tau is a pathogenic hallmark of tauopathies and a defining feature of Alzheimer's disease (AD). Pathological tau is targeted by autophagy for clearance, but autophagy dysfunction is indicated in tauopathy. While mitochondrial bioenergetic failure has been shown to precede the development of tau pathology, it is unclear whether energy metabolism deficiency is involved in tauopathy-related autophagy defects. Here, we reveal that stimulation of anaplerotic metabolism restores defective oxidative phosphorylation (OXPHOS) in tauopathy which, strikingly, leads to enhanced autophagy and pronounced tau clearance. OXPHOS-induced autophagy is attributed to increased ATP-dependent phosphatidylethanolamine biosynthesis in mitochondria. Excitingly, early bioenergetic stimulation boosts autophagy activity and reduces tau pathology, thereby counteracting memory impairment in tauopathy mice. Taken together, our study sheds light on a pivotal role of bioenergetic dysfunction in tauopathy-linked autophagy defects and suggests a new therapeutic strategy to prevent toxic tau buildup in AD and other tauopathies.

20.
Artigo em Inglês | MEDLINE | ID: mdl-39208603

RESUMO

Magnolia bark is a traditional Chinese medicine used for hypoglycaemia. With the widespread use of Magnolia bark, its resources are facing a serious shortage. To address this issue, a strategy based on high-coverage mass spectrometry (HCMS) and multidimensional chemical-biological analysis (MCBA) was proposed for the comprehensive exploration of Magnolia officinalis which is the main source of Magnolia bark. The strategy is divided into three main steps. In the first step, the stem bark, stem xylem, root bark, root xylem, leaf and rootlet of Magnolia officinalis were comprehensively analyzed using high-coverage mass spectrometry. In the second step, multivariate statistical analysis was used to explore the heterogeneity of the six parts and detect differential chemical components. In the third step, a combination of experimental screening and molecular docking was used to explore α-glucosidase inhibitors from Magnolia officinalis. Multidimensional chemical-biological analysis (MCBA) of Magnolia officinalis was achieved by combining the last two steps. Finally, a total of 103 compounds were identified from the whole plant of Magnolia officinalis. Differential components of stem bark, stem xylem, leaf, root bark, root xylem and rootlet were systematically revealed. A pair of positional isomers, namely magnolol and honokiol, were found to be α-glucosidase inhibitors. The activity of their combination is superior to that of each single compound, indicating that magnolol and honokiol are in a synergistic relationship. This strategy contributes to comprehensive exploitation of functional plants and effective alleviation of resource shortage. This study also provides a research paradigm for other similar traditional Chinese medicinal plants.


Assuntos
Magnolia , Espectrometria de Massas , Magnolia/química , Espectrometria de Massas/métodos , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/análise , Simulação de Acoplamento Molecular , Plantas Medicinais/química , Inibidores de Glicosídeo Hidrolases/análise , Inibidores de Glicosídeo Hidrolases/química
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