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1.
EMBO Rep ; 23(1): e53231, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34726300

RESUMO

The exon junction complex controls the translation, degradation, and localization of spliced mRNAs, and three of its core subunits also play a role in splicing. Here, we show that a fourth subunit, Barentsz, has distinct functions within and separate from the exon junction complex in Drosophila neuromuscular development. The distribution of mitochondria in larval muscles requires Barentsz as well as other exon junction complex subunits and is not rescued by a Barentsz transgene in which residues required for binding to the core subunit eIF4AIII are mutated. In contrast, interactions with the exon junction complex are not required for Barentsz to promote the growth of neuromuscular synapses. We find that the Activin ligand Dawdle shows reduced expression in barentsz mutants and acts downstream of Barentsz to control synapse growth. Both barentsz and dawdle are required in motor neurons, muscles, and glia for normal synapse growth, and exogenous Dawdle can rescue synapse growth in the absence of barentsz. These results identify a biological function for Barentsz that is independent of the exon junction complex.


Assuntos
Proteínas de Drosophila , Proteínas de Ligação a RNA , Animais , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Éxons/genética , Proteínas de Ligação a RNA/metabolismo , Sinapses/metabolismo
2.
Mol Microbiol ; 117(5): 1173-1195, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35344242

RESUMO

Aluminum salts have been successfully utilized as adjuvants to enhance the immunogenicity of vaccine antigens since the 1930s. However, the cellular mechanisms behind the immune adjuvanticity effect of these materials in antigen-presenting cells are poorly understood. In this study, we investigated the uptake and trafficking of aluminum oxy-hydroxide (AlOOH), in RAW 264.7 murine and U-937 human macrophages-like cells. Furthermore, we determined the impact that the adsorption to AlOOH particulates has on the trafficking of a Bordetella pertussis vaccine candidate, the genetically detoxified pertussis toxin (gdPT). Our results indicate that macrophages internalize AlOOH by constitutive macropinocytosis assisted by the filopodial protrusions that capture the adjuvant particles. Moreover, we show that AlOOH has the capacity to nonspecifically adsorb IgG, engaging opsonic phagocytosis, which is a feature that may allow for more effective capture and uptake of adjuvant particles by antigen-presenting cells (APCs) at the site of vaccine administration. We found that AlOOH traffics to endolysosomal compartments that hold degradative properties. Importantly, while we show that gdPT escapes degradative endolysosomes and traffics toward the retrograde pathway, as reported for the wild-type pertussis toxin, the adsorption to AlOOH diverts gdPT to traffic to the adjuvant's lysosome-type compartments, which may be key for MHC-II-driven antigen presentation and activation of CD4+ T cell. Thus, our findings establish a direct link between antigen adsorption to AlOOH and the intracellular trafficking of antigens within antigen-presenting cells and bring to light a new potential mechanism for aluminum adjuvancy. Moreover, the in-vitro single-cell approach described herein provides a general framework and tools for understanding critical attributes of other vaccine formulations.


Assuntos
Hidróxido de Alumínio , Alumínio , Adjuvantes Imunológicos/farmacologia , Alumínio/farmacologia , Hidróxido de Alumínio/farmacologia , Animais , Humanos , Lisossomos , Macrófagos , Camundongos , Toxina Pertussis/genética , Toxina Pertussis/farmacologia , Vacina contra Coqueluche/farmacologia
3.
Catheter Cardiovasc Interv ; 102(1): 155-158, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37210620

RESUMO

A 70-year-old man with history of transcatheter aortic valve-in-valve implantation was admitted because of suspected infective endocarditis (IE). Transesophageal echocardiogram did not reveal any vegetations, as the metallic stent frames caused significant artifacts. Position emission tomography was also negative. Intracardiac echocardiogram (ICE) was performed retrogradely through the ascending aorta, which showed clear vegetations over the stent frame of the transcatheter heart valve. Endocarditis after transcatheter aortic valve implantation was not uncommon. With increasing use of valve-in-valve procedures, echocardiographic diagnosis of IE would be more challenging. This case demonstrated the advantage of ICE over conventional echocardiography in visualizing the neo-aortic valve complex for diagnosing IE.


Assuntos
Endocardite Bacteriana , Endocardite , Infecções Relacionadas à Prótese , Substituição da Valva Aórtica Transcateter , Masculino , Humanos , Idoso , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Infecções Relacionadas à Prótese/diagnóstico por imagem , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/terapia , Resultado do Tratamento , Endocardite Bacteriana/diagnóstico por imagem , Endocardite Bacteriana/etiologia , Endocardite Bacteriana/cirurgia , Endocardite/etiologia , Endocardite/complicações , Substituição da Valva Aórtica Transcateter/efeitos adversos , Ecocardiografia/efeitos adversos
4.
J Chem Phys ; 159(16)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37870138

RESUMO

We introduce ACEpotentials.jl, a Julia-language software package that constructs interatomic potentials from quantum mechanical reference data using the Atomic Cluster Expansion [R. Drautz, Phys. Rev. B 99, 014104 (2019)]. As the latter provides a complete description of atomic environments, including invariance to overall translation and rotation as well as permutation of like atoms, the resulting potentials are systematically improvable and data efficient. Furthermore, the descriptor's expressiveness enables use of a linear model, facilitating rapid evaluation and straightforward application of Bayesian techniques for active learning. We summarize the capabilities of ACEpotentials.jl and demonstrate its strengths (simplicity, interpretability, robustness, performance) on a selection of prototypical atomistic modelling workflows.

5.
Cleft Palate Craniofac J ; 60(3): 367-375, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-34787010

RESUMO

Femoral facial syndrome (FFS) is a rare condition which may present with hypoplasia or aplasia of the femora and unusual facies characterized by long philtrum, thin upper lip and micrognathia. We present the case of a ten-month old infant with FFS who had retroglossal obstruction and who was treated with a pre-epiglottic baton plate. The pre-epiglottic baton plate can be a simple, non-invasive and effective tool for the clinical management of syndromic patients with mild-to-moderate upper airway obstruction due to micrognathia.


Assuntos
Obstrução das Vias Respiratórias , Micrognatismo , Síndrome de Pierre Robin , Humanos , Lactente , Micrognatismo/diagnóstico por imagem , Micrognatismo/cirurgia , Síndrome de Pierre Robin/complicações , Síndrome de Pierre Robin/terapia , Fêmur , Obstrução das Vias Respiratórias/diagnóstico por imagem , Obstrução das Vias Respiratórias/etiologia , Obstrução das Vias Respiratórias/cirurgia
6.
Chemistry ; 28(19): e202104575, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35170133

RESUMO

Weak light absorption of common Ir(III) complexes (e. g., using phenylpyridine as the ligand) has hindered their applications in photocatalytic hydrogen generation from water as an efficient photosensitizer. To address this issue, a series of cyclometalated Ir(III) complexes (Ir1-Ir5), featuring different electron-donating substituents to enhance the absorptivity, have been synthesized and studied as photosensitizers (PSs) for light-driven hydrogen production from water. Ir6-Ir7 were prepared as fundamental systems for comparisons. Electron donors, including 9-phenylcarbazole, triphenylamine, 4,4'-dimethoxytriphenylamine, 4,4'-di(N-hexylcarbazole)triphenylamine moieties were introduced on 6-(thiophen-2-yl)phenanthridine-based cyclometalating (C^N) ligands to explore the donor effect on the hydrogen evolution performance of these cationic Ir(III) complexes. Remarkably, Ir4 with 4,4'-dimethoxytriphenylamine achieved the highest turn-over number (TON) of 12 300 and initial turnover frequency (TOFi ) of 394 h-1 , with initial activity (activityi ) of 547 000 µmol g-1 h-1 and initial apparent quantum yield (AQYi ) of 9.59 %, under the illumination of blue light-emitting diodes (LEDs) for 105 hours, which demonstrated a stable three-component photocatalytic system with high efficiency. The TON (based on n(H2 )/n(PSr)) in this study is the highest value reported to date among the similar photocatalytic systems using Ir(III) complexes with Pt nanoparticles as catalyst. The great potential of using triphenylamine-based Ir(III) PSs in boosting photocatalytic performance has also been shown.

7.
Inorg Chem ; 61(10): 4384-4393, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35243862

RESUMO

Three multi-dentate coordinated chelates LnH2 (n = 1, 2, and 3), comprising a linked 1-(pyridin-2-yl)ethylbenzene and one pyrazolyl pyridine unit and showing either tridentate or tetradentate coordination modes, are successfully designed and synthesized. Dinuclear Ir(III) complexes [Ir(κ4-Ln)(µ-Cl)]2 bearing tetradentate coordinated κ4-Ln chelate (2a, n = 1; 2b, n = 2; 2c, n = 3) were next obtained en route from the respective intermediate [Ir(κ3-LnH)Cl(µ-Cl)]2 bearing the tridentate coordinated κ3-LnH chelate (1a, n = 1; 1b, n = 2; 1c, n = 3). Next, mononuclear Ir(III) complexes Ir(κ4-Ln)(thd) (3a, n = 1; 3b, n = 2; 3c, n = 3) with the tetradentate chelate were obtained upon treatment of 2 with 2,2,6,6-tetramethyl-3,5-heptanedione (thd)H in the presence of K2CO3. Concurrently, methylation of 2c in the presence of MeI and nBu4NCl afforded tridentate Ir(κ3-L3HMe)Cl3 (4) and, next, can be converted to tetradentate Ir(κ4-L3Me)Cl2 (5) by further cyclometalation and HCl elimination in refluxing diethylene glycol monoethyl ether solution. The Ir(III) complexes 3a, 4, and 5 were unambiguously identified using spectroscopic methods, together with single-crystal X-ray structural analyses on Ir(III) derivatives 3a, 4, and 5. Their photophysical and ,electrochemical properties and device fabrication properties were also investigated and compared with results from theoretical studies.

8.
Nature ; 540(7632): 242-247, 2016 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-27919077

RESUMO

N6-methyladenosine RNA (m6A) is a prevalent messenger RNA modification in vertebrates. Although its functions in the regulation of post-transcriptional gene expression are beginning to be unveiled, the precise roles of m6A during development of complex organisms remain unclear. Here we carry out a comprehensive molecular and physiological characterization of the individual components of the methyltransferase complex, as well as of the YTH domain-containing nuclear reader protein in Drosophila melanogaster. We identify the member of the split ends protein family, Spenito, as a novel bona fide subunit of the methyltransferase complex. We further demonstrate important roles of this complex in neuronal functions and sex determination, and implicate the nuclear YT521-B protein as a main m6A effector in these processes. Altogether, our work substantially extends our knowledge of m6A biology, demonstrating the crucial functions of this modification in fundamental processes within the context of the whole animal.


Assuntos
Adenosina/análogos & derivados , Drosophila melanogaster/fisiologia , Neurônios/fisiologia , Processos de Determinação Sexual/fisiologia , Adenosina/metabolismo , Processamento Alternativo , Animais , Comportamento Animal/fisiologia , Proteínas de Drosophila/química , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/enzimologia , Feminino , Masculino , Metiltransferases/química , Metiltransferases/metabolismo , Sistema Nervoso/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenótipo , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Proteínas de Ligação a RNA/genética , Processos de Determinação Sexual/genética
9.
Infancy ; 27(1): 197-206, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34791778

RESUMO

Engaging with music fosters prosocial responding in infants and toddlers. In this pilot study, we examined whether music that expresses contrasting emotions (happy vs. sad) was associated with toddlers' helpfulness. Seventy-five 18-month-olds from Hong Kong China were randomly assigned to engage with music with an experimenter in one of two conditions: happy- or sad-sounding music. After the musical engagement task, toddlers from both conditions completed the same set of helping tasks. For instrumental (action-based) helping, toddlers were significantly more helpful after engaging with happy-sounding music than with sad-sounding music. Our initial findings suggest that cues linked to happy- and sad-sounding music influence toddlers' prosocial responses.


Assuntos
Música , Emoções , Felicidade , Comportamento de Ajuda , Humanos , Lactente , Projetos Piloto
10.
Heart Lung Circ ; 31(11): e140-e142, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36055925

RESUMO

A 68-year old lady present with left ventricular free wall rupture and cardiac arrest post-myocardial infarction. This article illustrates a strategy combining pericardiocentesis with autologous transfusion together with VA-ECMO as a bridge to definitive surgical repair.


Assuntos
Oxigenação por Membrana Extracorpórea , Ruptura Cardíaca Pós-Infarto , Ruptura Cardíaca , Feminino , Humanos , Idoso , Pericardiocentese , Ruptura Cardíaca Pós-Infarto/cirurgia , Transfusão de Sangue Autóloga , Ruptura Cardíaca/cirurgia
11.
Biochem Cell Biol ; 97(1): 21-29, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29791809

RESUMO

Phagocytosis is an evolutionarily conserved process. In Protozoa, phagocytosis fulfills a feeding mechanism, while in Metazoa, phagocytosis diversified to play multiple organismal roles, including immune defence, tissue homeostasis, and remodeling. Accordingly, phagocytes display a high level of plasticity in their capacity to recognize, engulf, and process targets that differ in composition and morphology. Here, we review how phagocytosis adapts to its multiple roles and discuss in particular the effect of target morphology in phagocytic uptake and phagosome maturation.


Assuntos
Fenômenos Fisiológicos Celulares , Fagocitose/fisiologia , Fagossomos/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Humanos , Transdução de Sinais
12.
Chem Soc Rev ; 47(13): 4934-4953, 2018 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-29774340

RESUMO

In recent years, metallopolymers have attracted much attention as precursors to generate magnetic metal/metal alloy nanoparticles (NPs) through pyrolysis or photolysis because they offer the advantages of ease of solution processability, atomic level mixing and stoichiometric control over composition. The as-generated NPs usually possess narrow size distributions with precise control of composition and density per unit area. Moreover, patterned NPs can be achieved on various substrates in this way owing to the good film-forming property of metallopolymers and such work is important for many applications based on metal nanostructures. By combining the merits of both the solution processability of metallopolymers and nanoimprint lithography (NIL), a new platform can be created for fabricating bit-patterned media (BPM) and the next-generation of nanoscale ultra-high-density magnetic data storage devices. Furthermore, most of these metallopolymers can be used directly as a negative-tone resist to generate magnetic metallic nanostructures by electron-beam lithography and UV photolithography. Self-assembly and subsequent pyrolysis of metalloblock copolymers can also afford well-patterned magnetic metal or metal alloy NPs in situ with periodicity down to dozens of nanometers. In this review, we highlight the use of metallopolymer precursors for the synthesis of magnetic metal/metal alloy NPs and their nanostructures and the related applications.

13.
Small ; 13(43)2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28922550

RESUMO

A novel mesoporous nanosheet networked hybrid comprising Co3 O4 and Co3 (PO4 )2 is successfully synthesized using a facile and scalable method through calcinating the carbon, cobalt hydroxy carbonate, and cobalt phosphate composite precursor. Electron transfer from Co3 O4 to Co3 (PO4 )2 , together with the special networked structure and the porous nature of the nanosheets enable the Co3 (PO4 )2 -Co3 O4 hybrid to have a high oxygen evolution reaction (OER) activity and outstanding stability in alkaline electrolyte, e.g., an overpotential of 270 mV at current density of 10 mA cm-2 , and a Tafel slope of 39 mV dec-1 , which are superior to most non-noble metal-based OER electrocatalysts reported thus far and as well the commercial RuO2 electrocatalyst. Furthermore, Co3 (PO4 )2 -Co3 O4 hybrid is demonstrated to be used as an efficient cocatalyst to enhance the photoelectrochemical OER performance of BiVO4 photoanode. A significantly increased photocurrent density of 3.0 mA cm-2 at 1.23 V (vs reversible hydrogen electrode, RHE), and a potential reduction of 530 mV with respect to that of bare BiVO4 at the photocurrent density of 0.5 mA cm-2 are achieved. The electron transfer-induced enhancement of OER by a hybrid structure may pave the new routes for the design and synthesis of low-cost catalysts for electrochemical and photoelectrochemical oxygen evolution.

14.
Inorg Chem ; 56(17): 10311-10324, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28825489

RESUMO

A new series of bimetallic Cu(I) complexes 1-5 triply bridged by a monoanionic or charge-neutral functionalized 3-(2'-pyridyl)-1,2,4-triazole in a µ-η1(N),η2(N,N) tridentate binding mode and two bis(diphenylphosphino)methane (dppm) ligands have been synthesized. Complexes 1-5 are singly or doubly charged dinuclear Cu(I) species with an eight-membered Cu2C2P4 ring of {Cu(µ-dppm)2Cu} unit, in which 3 and 4 adopt the boat-boat conformation, while 1, 2, and 5 display the chair-boat form. In these dimeric copper(I) complex cations, one of the two Cu(I) ions is four-coordinated, in a highly distorted N2P2 tetrahedral environment and the other is three-coordinated, in a distorted NP2 trigonal planar arrangement. All these Cu(I) complexes exhibit a comparatively weak low-energy absorption in CH2Cl2 solution, ascribed to the charge-transfer transitions with appreciable 1MLCT contribution, as suggested by time-dependent density functional theory (TDDFT) analyses. Complexes 1-5 display good emission properties in both solution and solid states at ambient temperature, which are well-modulated via structural modification of 3-(2'-pyridyl)-1,2,4-triazole, including the alteration of the substituent type (-CF3, -H, -CH3, and -C(CH3)3) and position (ortho-, meta-, and para-position). Furthermore, the variation of the substituent (-CF3 and -C(CH3)3) on the 5-site of the 1,2,4-triazolyl ring markedly influences the proton activity of the 1,2,4-triazolyl-NH, thus leading to the formation of both singly and doubly charged bimetallic Cu(I) species regulated by the NH ↔ N- conversion, resulting from NH deprotonation of the 1,2,4-triazolyl ring.

15.
Inorg Chem ; 56(5): 2409-2416, 2017 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-28195717

RESUMO

It is well-known that the variation of noncovalent interactions of luminophores, such as π-π interaction, metal-to-metal interaction, and hydrogen-bonding interaction, can regulate their emission colors. Electrostatic interaction is also an important noncovalent interaction. However, very few examples of luminescence color tuning induced by electrostatic interaction were reported. Herein, a series of Zn(II)-bis(terpyridine) complexes (Zn-AcO, Zn-BF4, Zn-ClO4, and Zn-PF6) containing different anionic counterions were reported, which exhibit counterion-dependent emission colors from green-yellow to orange-red (549 to 622 nm) in CH2Cl2 solution. More importantly, it was found that the excited states of these Zn(II) complexes can be regulated by changing the electrostatic interaction between Zn2+ and counterions. On the basis of this controllable excited state, white light emission has been achieved by a single molecule, and a white light-emitting device has been fabricated. Moreover, a novel type of data decryption system with Zn-PF6 as the optical recording medium has been developed by the two-photon excitation technique. Our results suggest that rationally controlled excited states of these Zn(II) complexes by regulating electrostatic interaction have promising applications in various optoelectronic fields, such as light-emitting devices, information recording, security protection, and so on.

16.
Alcohol Alcohol ; 52(5): 595-609, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28591801

RESUMO

AIM: To appraise existing alcohol guidelines for identifying and managing harmful alcohol use in primary healthcare settings. METHODS: Seven databases and 18 health organization or medical society websites were systematically searched from inception to 31 October 2016. Guidelines in English language, developed by a national or international medical specialty society, government or health organization, and containing recommendations for identifying and managing harmful use of alcohol in primary healthcare settings, were included. The Appraisal of Guidelines Research and Evaluation II (AGREE II) instrument was used to appraise the guidelines. RESULTS: Of the 970 literature identified, 17 were included for review, with 13 guidelines developed for use in Western countries and 4 for international use. The AGREE II scores ranged from 2.0 to 5.3, out of 7. Variations in terminology of harmful alcohol use were seen, with 'harmful drinking' and 'problem drinking' being mostly used. All guidelines were in favor of screening and brief interventions due to their effectiveness and cost-effectiveness. Potential benefits and costs of applying screening and brief interventions were found, but there was a lack of evidence for long-term effects or specific populations. CONCLUSIONS: All 17 guidelines recommended screening and brief interventions due to its associated health and financial benefits. Policy makers are highly encouraged to integrate these practices into primary healthcare settings taking the drinking status, culture and resources into account. SHORT SUMMARY: Screening and brief interventions were recommended by all 17 guidelines on managing patients with harmful use of alcohol in primary healthcare settings. Policy makers and healthcare practitioners are highly encouraged to implement these recommendations.


Assuntos
Alcoolismo/prevenção & controle , Guias de Prática Clínica como Assunto/normas , Atenção Primária à Saúde/normas , Humanos
17.
Chem Soc Rev ; 45(19): 5264-95, 2016 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-27430525

RESUMO

Insertion of transition metal elements into organic polymeric scaffolds enables a nice coupling of the intriguing physical traits of metal complexes such as electronic, optical and magnetic properties with the solution processability of carbon-based macromolecules. The propensity of these metal-based polymers towards exhibiting metal-metal interactions can also provide additional means for manipulating the structural order and electronic coupling in the molecules. Among these metallopolymers, rigid-rod transition metal σ-acetylide polymers, or polymetallaynes in short, are of much current interest. These organometallic polymers are important functional materials showing unique characteristics including electrical semiconductivity, photo-/electroluminescence, non-linear optical properties, liquid crystallinity, chemosensing capability and photovoltaic effect. Recently, there has been an impressive progress of functional polymetallaynes consisting of a variety of conjugated organic bridging moieties and transition metals. In this review, we summarize the structure-property-function relationships of polymetallaynes of different transition metals, with a major focus on the effect of transition metals and the structural modification of ligands in activating their multifunctional properties. Different emerging applications can thus be realized, for example, as the converters for both light/electricity signals, sensor protectors against intense laser beam and patternable precursors to magnetic metal alloy nanoparticles for data storage, etc.

18.
J Biol Chem ; 290(15): 9919-28, 2015 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-25713145

RESUMO

Lysosomes and the yeast vacuole are degradative and acidic organelles. Phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2), a master architect of endolysosome and vacuole identity, is thought to be necessary for vacuolar acidification in yeast. There is also evidence that PtdIns(3,5)P2 may play a role in lysosomal acidification in higher eukaryotes. Nevertheless, these conclusions rely on qualitative assays of lysosome/vacuole pH. For example, quinacrine, an acidotropic fluorescent base, does not accumulate in the vacuoles of fab1Δ yeast. Fab1, along with its mammalian ortholog PIKfyve, is the lipid kinase responsible for synthesizing PtdIns(3,5)P2. In this study, we employed several assays that quantitatively assessed the lysosomal and vacuolar pH in PtdIns(3,5)P2-depleted cells. Using ratiometric imaging, we conclude that lysosomes retain a pH < 5 in PIKfyve-inhibited mammalian cells. In addition, quantitative fluorescence microscopy of vacuole-targeted pHluorin, a pH-sensitive GFP variant, indicates that fab1Δ vacuoles are as acidic as wild-type yeast. Importantly, we also employed fluorimetry of vacuoles loaded with cDCFDA, a pH-sensitive dye, to show that both wild-type and fab1Δ vacuoles have a pH < 5.0. In comparison, the vacuolar pH of the V-ATPase mutant vph1Δ or vph1Δ fab1Δ double mutant was 6.1. Although the steady-state vacuolar pH is not affected by PtdIns(3,5)P2 depletion, it may have a role in stabilizing the vacuolar pH during salt shock. Overall, we propose a model in which PtdIns(3,5)P2 does not govern the steady-state pH of vacuoles or lysosomes.


Assuntos
Lisossomos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Vacúolos/metabolismo , Animais , Linhagem Celular , Fluorometria , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Concentração de Íons de Hidrogênio , Lisossomos/química , Camundongos , Microscopia de Fluorescência , Mutação , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo , Vacúolos/química
19.
Chemistry ; 22(11): 3750-7, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26660631

RESUMO

Three new unsymmetrical phenothiazine-based platinum(II) bis(acetylide) complexes PT1-PT3 with different electron-donating arylacetylide ligands were synthesized and characterized. Their photophysical, electrochemical, and photovoltaic properties have been fully investigated and the density functional theory (DFT) calculations have been carried out. Under AM 1.5 irradiation (100 mW cm(-2)), the PT1-based dye-sensitized solar cell (DSSC) device exhibited an attractive power conversion efficiency (η) up to 5.78 %, with a short-circuit photocurrent density (J(sc)) of 10.98 mA cm(-2), an open-circuit photovoltage (V(oc)) of 0.738 V, and a fill factor (ff) of 0.713. These findings provide strong evidence that platinum-acetylide complexes have great potential as promising photosensitizers in DSSC applications.

20.
Inorg Chem ; 55(4): 1720-7, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26814683

RESUMO

Phosphorescent dinuclear iridium(III) complexes that can show high luminescent efficiencies and good electroluminescent abilities are very rare. In this paper, highly phosphorescent 2-phenylpyrimidine-based dinuclear iridium(III) complexes have been synthesized and fully characterized. Significant differences of the photophysical and electrochemical properties between the mono- and dinuclear complexes are observed. The theoretical calculation results show that the dinuclear complexes adopt a unique molecular orbital spatial distribution pattern, which plays the key role of determining their photophysical and electrochemical properties. More importantly, the solution-processed organic light-emitting diode (OLED) based on the new dinuclear iridium(III) complex achieves a peak external quantum efficiency (η(ext)) of 14.4%, which is the highest η(ext) for OLEDs using dinuclear iridium(III) complexes as emitters. Besides, the efficiencies of the OLED based on the dinuclear iridium(III) complex are much higher that those of the OLED based on the corresponding mononuclear iridium(III) complex.

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