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Host-derived fatty acids are an important carbon source for pathogenic mycobacteria during infection. How mycobacterial cells regulate the catabolism of fatty acids to serve the pathogenicity, however, remains unknown. Here, we identified a TetR-family transcriptional factor, FdmR, as the key regulator of fatty acid catabolism in the pathogen Mycobacterium marinum by combining use of transcriptomics, chromatin immunoprecipitation followed by sequencing, dynamic 13C-based flux analysis, metabolomics, and lipidomics. An M. marinum mutant deficient in FdmR was severely attenuated in zebrafish larvae and adult zebrafish. The mutant showed defective growth but high substrate consumption on fatty acids. FdmR was identified as a long-chain acyl-coenzyme A (acyl-CoA)-responsive repressor of genes involved in fatty acid degradation and modification. We demonstrated that FdmR functions as a valve to direct the flux of exogenously derived fatty acids away from ß-oxidation toward lipid biosynthesis, thereby avoiding the overactive catabolism and accumulation of biologically toxic intermediates. Moreover, we found that FdmR suppresses degradation of long-chain acyl-CoAs endogenously synthesized through the type I fatty acid synthase. By modulating the supply of long-chain acyl-CoAs for lipogenesis, FdmR controls the abundance and chain length of virulence-associated lipids and mycolates and plays an important role in the impermeability of the cell envelope. These results reveal that despite the fact that host-derived fatty acids are used as an important carbon source, overactive catabolism of fatty acids is detrimental to mycobacterial cell growth and pathogenicity. This study thus presents FdmR as a potentially attractive target for chemotherapy.
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Ácidos Graxos/metabolismo , Lipogênese/fisiologia , Mycobacterium marinum/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Lipólise , Metabolismo/fisiologia , Modelos Animais , Mycobacterium/metabolismo , Infecções por Mycobacterium não Tuberculosas/metabolismo , Infecções por Mycobacterium não Tuberculosas/fisiopatologia , Oxirredução , Fatores de Transcrição/metabolismo , Virulência/fisiologia , Peixe-Zebra/metabolismo , Peixe-Zebra/microbiologiaRESUMO
BACKGROUND: The impact of insulin resistance on the prognosis of heart failure with preserved ejection fraction (HFpEF) remains unknown. This study aimed to investigate the association between the triglyceride-glucose (TyG) index, an easily calculated marker of insulin resistance, and the long-term prognosis of HFpEF. METHODS: A total of 823 patients with HFpEF were enrolled in the study. The TyG index was determined using the formula ln(fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2). The primary endpoint was all-cause death. The secondary endpoints were cardiovascular (CV) death and heart failure (HF) rehospitalization. Restricted cubic spline, multivariate Cox proportional hazard models, and competing risk models were used for analyses. RESULTS: During a median follow-up period of 3.16 years, 147 (17.8%) all-cause deaths, 139 (16.8%) CV deaths, and 222 (27.0%) HF rehospitalizations occurred. Restricted cubic spline analysis revealed a J-shaped association between the TyG index and the mortality and rehospitalization rates. In the multivariate Cox proportional hazard models, compared with those in the lowest TyG index tertile, patients in the highest tertile exhibited the greatest susceptibility to all-cause death (HR 1.53, 95% CI 1.19-1.98) and CV death (HR 1.52, 95% CI 1.19-1.96). In the competing risk model, a significant association between the TyG index and HF rehospitalization was observed (HR 1.31, 95% CI, 1.07-1.61). CONCLUSION: A high TyG index is associated with an increased risk of mortality and rehospitalization in patients with HFpEF. The TyG index may serve as a promising prognostic marker for patients with HFpEF.
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Insuficiência Cardíaca , Resistência à Insulina , Humanos , Fatores de Risco , Insuficiência Cardíaca/diagnóstico , Biomarcadores , Volume Sistólico , Triglicerídeos , Glicemia , Prognóstico , Glucose , Medição de RiscoRESUMO
Although organ hypofunction and immunosuppression are life-threatening features of severe sepsis, the hypofunctioning organs and immune cells usually regain normal functionality if patients survive. Because tissue interstitial fluid can become acidic during the septic response, we tested the hypothesis that low extracellular pH (pHe) can induce reversible metabolic and functional changes in peritoneal macrophages from C57BL/6J mice. When compared with macrophages cultured at normal pHe, macrophages living in an acidic medium used less glucose and exogenous fatty acid to produce ATP. Lactate, glutamine, and de novo-synthesized fatty acids supported ATP production by mitochondria that gained greater mass, maximal oxygen consumption rate, and spare respiratory capacity. The cells transitioned to an M2-like state, with altered immune responses to LPS and slightly decreased phagocytic ability, yet they regained basal energy production, normal mitochondrial function, and proinflammatory responsiveness when neutral pHe was restored. Low pHe induces changes that support macrophage survival while rendering the cells less proinflammatory (more "tolerant") and less able to phagocytose bacteria. Macrophage responses to low interstitial pH may contribute to the reversible organ hypofunction and immunoparalysis noted in many patients with sepsis.
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Espaço Extracelular/imunologia , Imunidade Inata/imunologia , Macrófagos Peritoneais/imunologia , Sepse/imunologia , Animais , Células Cultivadas , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos C57BLRESUMO
To evaluate the efficacy of multimodal analgesia of flurbiprofen axetil, nalbuphine hydrochloride and patient controlled intravenous analgesia (PCIA) on inflammatory factor levels and stress response in patients after laparoscopic radical gynecological malignancy surgery. The data of 100 patients admitted to our hospital from May 2019 to May 2020 for laparoscopic radical gynecological malignancy surgery were retrospectively analyzed and they were assigned (1:1) to either an experimental group or a control group according to the alphabetical order of their initials. The experimental group was given preemptive analgesia with flurbiprofen axetil, postoperative analgesia with nalbuphine hydrochloride, and PCIA and the control group was given conventional analgesic measures. The pain scores at 1h, 6h, 12h, 24h and 48h postoperatively in the experimental group were remarkably lower than those in the control group (P<0.001). The experimental group showed significantly lower inflammatory factor levels, pain mediator levels and stress response indexes in the morning before surgery, 1d, and 2d after surgery than the control group (P<0.001). The multimodal analgesia of flurbiprofen axetil, nalbuphine hydrochloride and PCIA can effectively alleviate the stress response and inflammatory response in patients after radical gynecologic malignancy surgery and the patients' pain perception is reduced with a high safety profile.
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Flurbiprofeno , Neoplasias dos Genitais Femininos , Laparoscopia , Nalbufina , Analgesia Controlada pelo Paciente , Analgésicos Opioides/uso terapêutico , Feminino , Flurbiprofeno/análogos & derivados , Flurbiprofeno/uso terapêutico , Humanos , Laparoscopia/efeitos adversos , Nalbufina/efeitos adversos , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Estudos RetrospectivosRESUMO
BACKGROUND AND AIMS: Treatment of non-alcoholic steatohepatitis (NASH) is challenging, because suppressing fibrotic progression has not been achieved consistently by drug candidates currently in clinical trials. The aim of this study was to investigate the molecular interplays underlying NASH-associated fibrosis in a mouse NASH model and human specimens. METHODS: Mice were divided into 4 groups: Controls; NASH (high fat/Calorie diet plus high fructose and glucose in drinking water, HFCD-HF/G) for 16 weeks; HFCD-HF/G plus docosahexaenoic acid (DHA) for 16 or 8 weeks. RESULTS: Along with NASH progression, fibrotic deposition was documented in HFCD-HF/G-fed mice. Liver succinate content was significantly increased along with decreased expression of succinate dehydrogenase-A (SDH-A) in these mice; whereas, GPR-91 receptor expression was much enhanced in histology compared to control mice, and co-localized histologically with hepatic stellate cells (HSCs). Succinate content was increased in fatty acid-overloaded primary hepatocytes with significant oxidant stress and lipotoxicity. Exposure to succinate led to up-regulation of GPR-91 receptor in primary and immortalized HSCs. In contrast, suppression of GPR-91 receptor expression abolished succinate stimulatory role in GPR-91 expression and extracellular matrix production in HSCs. All these changes were minimized or abrogated by DHA supplementation in vivo or in vitro. Moreover, GPR-91 receptor expression correlates with severity of fibrosis in human NASH biopsy specimens. CONCLUSION: Succinate accumulation in steatotoic hepatocytes may result in HSC activation through GPR-91 receptor signalling in NASH progression, and the cross-talk between hepatocytes and HSC through GPR-91 signalling is most likely to be the molecular basis of fibrogenesis in NASH.
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Hepatopatia Gordurosa não Alcoólica , Animais , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/farmacologia , Fibrose , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/patologia , Ácido SuccínicoRESUMO
Macrophages are the first-line host defense that the invading Mycobacterium tuberculosis (Mtb) encounters. It has been recently reported that host aerobic glycolysis was elevated post the infection by a couple of virulent mycobacterial species. However, whether this metabolic transition is required for host defense against intracellular pathogens and the underlying mechanisms remain to be further investigated. A pathogenic mycobacterial species, M. marinum, is genetically close to Mtb and was utilized in this study. Through analyzing cellular carbon metabolism of RAW 264.7 (a murine macrophage-like cell line) post M. marinum infection, a strong elevation of glycolysis was observed. Next, three glycolysis inhibitors were examined for their ability to inhibit mycobacterial proliferation inside RAW264.7 macrophages. Among them, a glucose analog, 2-deoxyglucose (2-DG) displayed a protective role against mycobacterial infection. Treatment with 2-DG at concentrations of 0.5 or 1 mM significantly induced autophagy and decreased the phagocytosis of M. marinum by macrophages. Moreover, 2-DG pre-treatment exerted a significantly protective effect on zebrafish larvae by limiting the proliferation of M. marinum, and such effect was correlated to tumor necrosis factor alpha (TNF-α) as the 2-DG pre-treatment increased the expression of TNF-α in both mouse peritoneal macrophages and zebrafish. On the contrary, the 2-DG treatment post infection did not restrain proliferation of M. marinum in WT zebrafish, and even accelerated bacterial replication in TNF-α-/- zebrafish. Together, modulation of glycolysis prior to infection boosts host immunity against M. marinum infection, indicating a potential intervention strategy to control mycobacterial infection.
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Doenças dos Peixes/metabolismo , Glicólise , Infecções por Mycobacterium não Tuberculosas/veterinária , Mycobacterium marinum/fisiologia , Peixe-Zebra , Aerobiose , Animais , Doenças dos Peixes/microbiologia , Camundongos , Infecções por Mycobacterium não Tuberculosas/metabolismo , Infecções por Mycobacterium não Tuberculosas/microbiologia , Células RAW 264.7RESUMO
BACKGROUND: The σ54 factor controls unique promoters and interacts with a specialized activator (enhancer binding proteins [EBP]) for transcription initiation. Although σ54 is present in many Clostridiales species that have great importance in human health and biotechnological applications, the cellular processes controlled by σ54 remain unknown. RESULTS: For systematic analysis of the regulatory functions of σ54, we performed comparative genomic reconstruction of transcriptional regulons of σ54 in 57 species from the Clostridiales order. The EBP-binding DNA motifs and regulated genes were identified for 263 EBPs that constitute 39 distinct groups. The reconstructed σ54 regulons contain the genes involved in fermentation and amino acid catabolism. The predicted σ54 binding sites in the genomes of Clostridiales spp. were verified by in vitro binding assays. To our knowledge, this is the first report about direct regulation of the Stickland reactions and butyrate and alcohols synthesis by σ54 and the respective EBPs. Considerable variations were demonstrated in the sizes and gene contents of reconstructed σ54 regulons between different Clostridiales species. It is proposed that σ54 controls butyrate and alcohols synthesis in solvent-producing species, regulates autotrophic metabolism in acetogenic species, and affects the toxin production in pathogenic species. CONCLUSIONS: This study reveals previously unrecognized functions of σ54 and provides novel insights into the regulation of fermentation and amino acid metabolism in Clostridiales species, which could have potential applications in guiding the treatment and efficient utilization of these species.
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Clostridiales/genética , Genômica , Regulon/genética , Álcoois/metabolismo , Butiratos/metabolismo , Clostridiales/metabolismo , Filogenia , Especificidade da Espécie , Ativação TranscricionalRESUMO
11ß-Hydrocortisone (11ß-HC) is an important anti-inflammatory drug and intermediate for the synthesis of other steroids. One of the methods for the synthesis of 11ß-HC is the asymmetric reduction of cortisone catalyzed by a highly regioselective and stereoselective 11ß-hydroxysteroid dehydrogenase (11ß-HSDH). However, this process has been prohibited by the poor soluble expression of the membrane-anchoring protein 11ß-HSDH in prokaryotes. To overcome this obstacle, a mutant III-1G1 (Phe80Leu/Thr105Ser/Ala260Thr/Tyr274Stop) truncated at position 274 with improved yield of soluble protein was stepwise obtained from the 11ß-HSDH from guinea pig by random mutagenesis combining with structural complementation assay and C-terminal truncating library screening. The improved 11ß-HSDH mutant and glucose dehydrogenase (GDH) from Bacillus subtilis were coexpressed in Escherichia coli. The resulting whole-cell biocatalyst catalyzed the reduction of cortisone to 11ß-HC with 98 % conversion in 20 h, laying foundation for the development of an asymmetric reduction process for the production of 11ß-HC.
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Cortisona/metabolismo , Hidrocortisona/metabolismo , Hidroxiesteroide Desidrogenases/genética , Hidroxiesteroide Desidrogenases/metabolismo , Engenharia de Proteínas , Animais , Bacillus subtilis/enzimologia , Bacillus subtilis/genética , Biotransformação , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Glucose 1-Desidrogenase/genética , Glucose 1-Desidrogenase/metabolismo , Cobaias/genética , Hidroxiesteroide Desidrogenases/química , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Oxirredução , Deleção de Sequência , SolubilidadeRESUMO
Three-dimensional donor-acceptor (D-A) type conjugated porous polymers (CPPs) was designed and synthesized via imine condensation of copper tetraaminoporphyrin (CuTAPP) as donor and 1,3,5-tris-(4-formyl phenyl) triazine (TFPT) as acceptor, named as CuPT-CPP. The CuPT-CPP possesses a high specific surface area (73.7 m2/g) and excellent photophysical properties. The simultaneous introduction of the organometallic molecules and D-A structures in CuPT-CPP could be broadened the visible-light response range (400-800 nm) and facilitated efficient photogenerated carrier separation and transportation. As heterogeneous photocatalysts, CuPT-CPP has excellent photocatalytic performances under visible light irradiation, leading to excellent model pollutant rhodamine B degradation efficiency up to about 100% in 3 h, it has superb stability and reusability during the photocatalytic processes, and CuPT-CPP also exhibited broad substrate adaptability, which could photocatalytic degradation of methylene blue (MB), methyl orange (MO), and tetracycline hydrochloride (TC). This work indicates that three-dimensional D-A type porphyrin- and triazine-based CuPT-CPP has great potential in the practical application of photocatalysis.
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Poluentes Ambientais , Porfirinas , Água , Fotólise , Porosidade , Metais , PolímerosRESUMO
Conjugated porous polymers (CPPs) are a kind of promising sensing materials for the detection of nitroaromatic compounds, but their sensing applications in aqueous media are limited because of their poor dispersity or solubility in water. In this study, we prepared anthracene and tetraphenylsilane based CPPs named PSiAn by conventional Suzuki coupling and Suzuki-miniemulsion polymerization, respectively. The structure, morphology and porosity of the CPPs were characterized by Fourier Transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR), transmission electron microscope (TEM) and N2 sorption isotherm, respectively. Both of the CPPs have porous structure which is beneficial for the adsorption and diffusion of the analytes within them. The particle size of PSiAn nanoparticles prepared by Suzuki-miniemulsion polymerization is 10-40 nm from the TEM image, which facilitates the dispersion in the aqueous phase. Combined with the porosity and nanoparticle morphology, PSiAn nanoparticles realized the efficient photoluminescence (PL) sensing of nitroaromatic explosives in aqueous phase. The limit of detection (LOD) and limit of quantitation (LOQ) of PSiAn nanoparticles for 2,4,6-trinitrophenol (TNP) detection in the pure aqueous phase are 0.33 µM and 1.11 µM, respectively. Meanwhile, the good selectivity and anti-interference in presence of other nitro-compounds were observed. Furthermore, the spike/recovery test for the TNP detection in real water samples by PL sensing based on PSiAn nanoparticles indicates the quantitative recovery of TNP from 100.74 % to 101.00 %. The electrochemical test, ultraviolet-visible absorption spectra, excitation and emission spectra, and time-resolved PL spectra were investigated to explore the PL sensing mechanism. As a result, it is found that the fluorescence inner filter effect might be the predominant quenching mechanism during the detection of nitrophenolic compounds such as TNP and 4-nitrophenol (4-NP).
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In recent years, with the rapid development of ultrastrong and ultrafast lasers, it has become essential to develop new materials with excellent nonlinear optical (NLO) properties. Porphyrin-based metal-organic frameworks (MOFs) have great potential for application in the field of NLO due to their large conjugated structure and good stability. As a typical porphyrin-based MOF, porphyrin paddle-wheel framework-3 (PPF-3) has been prepared and applied in the fields of catalysis and sensing, yet the investigation of PPF-3 in NLO remains unexplored. In this study, the ZnS/PPF-3 composite was successfully prepared using a solvent thermal method to in situ load ZnS on the surface of PPF-3. Utilizing the Z-scan technique, the NLO properties of ZnS, PPF-3, and ZnS/PPF-3 composite were investigated under different input energy intensities. ZnS/PPF-3 composite material exhibits significantly enhanced NLO properties, with the third-order nonlinear absorption coefficient (ßeff) of up to 7.00 × 10-10 m/W and a limiting threshold as low as 1.52 J/cm2, indicating its promising application potential value in the field of optical limiting. To enhance the practical utility, the ZnS/PPF-3/PVA film was prepared via the drop-casting method, achieving a maximum ßeff of 5.00 × 10-8 m/W. The smaller optical bandgap of ZnS/PPF-3 and electron transfer from PPF-3 to ZnS are the key factors that enable the ZnS/PPF-3 composite to a superior NLO performance.
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Porphyrins and their derivatives have excellent photophysical and electrochemical properties, which have attracted great interest in the fields of catalysis, biosensing, gas storage, solar cells, biomedicine, etc. However, the inherent limitations, such as self-quenching, weak absorption at biological spectral windows and poor photochemical stability, severely hinder their applications in biomedicine, especially in the field of photodynamic therapy (PDT). In recent years, metal-organic frameworks (MOFs) have received increasing attention as a class of hybrid porous coordination polymers assembled from metal ions/secondary building units (SBUs) and organic linkers. By introducing porphyrins into MOFs via the encapsulation in the pores as well as grafting on the surface to form porphyrin@MOFs or using porphyrins as organic linkers to construct porphyrin-MOFs, not only the unique properties of porphyrins and MOFs are combined, but also the limitations of porphyrins are overcome and their applications are facilitated in the biomedicine field. This article reviews important synthetic strategies of forming porphyrin-based MOFs (including porphyrin@MOFs and porphyrin-MOFs), which focuses on the recent research achievements and progress in PDT and tumor therapy fields. Furthermore, by carefully designing the composition of MOFs (such as the modification of organic linkers), MOFs could respond to the tumor microenvironment for on-demand treatment. In addition, some other strategies, including chemotherapy, photothermal therapy (PTT) and the latest cancer immunotherapy, are also combined in the review. Finally, the challenges and prospects in biomedical applications of this class of emerging materials are discussed.
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Estruturas Metalorgânicas , Fotoquimioterapia , Porfirinas , Estruturas Metalorgânicas/química , Porfirinas/química , Portadores de Fármacos/química , CatáliseRESUMO
The cross-linked conjugated polymer poly(tetraphenylethene-co-biphenyl) (PTPEBP) nanoparticles were prepared by Suzuki-miniemulsion polymerization. The structure, morphology, and pore characteristics of PTPEBP nanoparticles were characterized by FTIR, NMR, SEM, and nitrogen adsorption and desorption measurements. PTPEBP presents a spherical nanoparticle morphology with a particle size of 56 nm; the specific surface area is 69.1 m2/g, and the distribution of the pore size is centered at about 2.5 nm. Due to the introduction of the tetraphenylethene unit, the fluorescence quantum yield of the PTPEBP nanoparticles reaches 8.14% in aqueous dispersion. Combining the porosity and nanoparticle morphology, the fluorescence sensing detection toward nitroaromatic explosives in the pure aqueous phase has been realized. The Stern-Volmer quenching constant for 2,4,6-trinitrophenol (TNP) detection is 2.50 × 104 M-1, the limit of detection is 1.07 µM, and the limit of quantification is 3.57 µM. Importantly, the detection effect of PTPEBP nanoparticles toward TNP did not change significantly after adding other nitroaromatic compounds, indicating that the anti-interference and selectivity for TNP detection in aqueous media is remarkable. In addition, the spike recovery test demonstrates the potential of PTPEBP nanoparticles for detecting TNP in natural environmental water samples.
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Microbial utilization and conversion of organic one-carbon compounds, such as formate and methanol that can be easily produced from CO2, has emerged as an attractive approach for biorefinery. In this study, we discovered Clostridium beijerinckii NCIMB 8052, a typical solventogenic Clostridium strain, to be a native formate-utilizing bacterium. 13C isotope analysis showed that formate could be metabolized via both assimilation and dissimilation pathways in C. beijerinckii NCIMB 8052. Notably, the use of formate as the supplementary substrate by this strain could significantly enhance its glucose consumption and ABE (acetone-butanol-ethanol) production, largely due to the up-regulation of genes responsible for glycolysis and glucose transport under formate stress. Based on these findings, we further improved formate tolerance of C. beijerinckii NCIMB 8052 by adaptive laboratory evolution, generating an evolved strain Cbei-FA01. The Cbei-FA01 strain could produce 23.0 g/L of ABE solvents using glucose and formate as dual substrates, â¼50% higher than that of the wild-type strain under the same condition. Moreover, such a promotion effect of formate on ABE production by Cbei-FA01 was also observed in fermenting a glucose-xylose mixture. This work reveals a previously unreported role of formate in biological ABE production, providing a new approach to utilize this one-carbon source.
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In this paper, we describe a bipolar molecular design for small molecule solution-processed organic light emitting diodes (OLEDs). Combining the rigidity of the conjugated emissive cores and the flexibility of the peripheral alkyl-linked carbazole groups, two series of highly efficient bipolar RGB (red, green, blue) emitters have been synthesized and characterized. The emissive cores are composed of electron-withdrawing groups; the carbazole groups endow the materials electron-donating units. Such bipolar structures are advantageous for the carrier injection and balance. Four peripheral carbazole groups are introduced in T-series materials (TCDqC, TCSoC, TCBzC, TCNzC), and another four in O-series materials (OCDqC, OCSoC, OCBzC, OCNzC). With the single-layer device configuration of ITO/PEDOT:PSS/emitting layer/CsF/Al, two green devices exhibited excellent performance with a maximum luminescence efficiency of over 6.4 cd A(-1), and a high maximum luminance of more than 6700 cd m(-2). In addition, compared with the T-series, the luminescence efficiency of blue and red devices based on O-series materials increased from 1.6 to 2.8 cd A(-1) and 0.2 to 1.3 cd A(-1), respectively. To our knowledge, the performance of the blue device based on OCSoC is among the best of the blue small-molecule solution-processed single-layer devices reported so far.
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In our work, a flurry of original porphyrin-based polymers covalently functionalized g-C3N4 nanohybrids were constructed and nominated as PPorx-g-C3N4 (x = 1, 2 and 3) through click chemistry between porphyrin-based polymers with alkyne end-groups [(PPorx-C≡CH (x = 1, 2 and 3)] and azide-functionalized graphitic carbon nitride (g-C3N4-N3). Due to the photoinduced electron transfer (PET) between porphyrin-based polymers [PPorx (x = 1, 2 and 3)] group and graphite phase carbon nitride (g-C3N4) group in PPorx-g-C3N4 nanohybrids, the PPorx-g-C3N4 nanohybrids exhibited better non-linear optical (NLO) performance than the corresponding PPorx-C≡CH and g-C3N4-N3. It found that the imaginary third-order susceptibility (Im [χ(3)]) value of the nanohybrids with different molecular weight (MW) of the pPorx group in the nanohybrids ranged from 2.5×103 to 7.0 × 103 g mol-1 was disparate. Quite interestingly, the Im [χ(3)] value of the nanohybrid with a pPorx group's MW of 4.2 × 103 g mol-1 (PPor2-g-C3N4) was 1.47 × 10-10 esu, which exhibited the best NLO performance in methyl methacrylate (MMA) of all nanohybrids. The PPorx-g-C3N4 was dispersed in polymethyl methacrylate (PMMA) to prepare the composites PPorx-g-C3N4/PMMA since PMMA was widely used as an alternative to glass. PPor2-g-C3N4/PMMA showed the excellent NLO performance of all nanohybrids with the Im [χ(3)] value of 2.36 × 10-10 esu, limiting threshold of 1.71 J/cm2, minimum transmittance of 8% and dynamic range of 1.09 in PMMA, respectively. It suggested that PPorx-g-C3N4 nanohybrids were potential outstanding NLO materials.
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Novel blue phosphor host, PCNCzSi, using 3,6-linked carbazole with δ-π tetraphenylsilane segment as the main chain modified by peripheral cyanohexyl group was designed. The Si-carbazole backbone entitles the polymer with wide bandgap, high E(T) and good hole transporting ability. The introduction of peripheral CN group with high electron affinity enhances the electron injecting property of the polymer revealed by electron-only device and UPS measurement. Highly efficient spin-coated phosphorescent polymer light-emitting device, using PCNCzSi as the host for blue iridium complex, FIrpic, was realized. The maximum luminous efficiency and maximum external quantum efficiency of the device were 15 cd/A and 6.7%, respectively, which are very high values for blue phosphorescent device using polymers as hosts as known.
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Medições Luminescentes/instrumentação , Polímeros/química , Luminescência , Estrutura Molecular , Polímeros/síntese químicaRESUMO
OBJECTIVE: This research was designed to probe into the effect of multimodal analgesia on gynecological cancer patients after radical resection. METHODS: Ninety-eight cervical cancer patients undergoing laparoscopic radical resection in our hospital were included. Thereinto, 47 in the research group (RG) were given multimodal analgesia, and 51 in the control group (CG) were given conventional postoperative analgesia. The time of operation, anesthesia recovery room observation and extubation, postoperative NRS pain score, and the clinical manifestations of both groups were observed. The activity within three days after operation, the incidence of postoperative complications, hospitalization time and quality of life of both groups were compared. RESULTS: The operation time of the RG was higher than that of the CG (P < 0.05), and the time of observation and extubation in the anesthesia room were lower than those in the CG (P < 0.05); the NRS pain score was lower than that of the CG (P < 0.05); the first time to get out of bed, and time of exhaust and diet were shorter than those of the CG (P < 0.05); the activity was better than that of the CG within three days after operation (P < 0.05); the incidence of complications was markedly lower than that in the CG (P < 0.05); the hospitalization time was shorter than that of the CG (P < 0.05); the postoperative quality of life was shorter than that in the CG (P < 0.05). CONCLUSION: Multimodal analgesia is safe and effective for patients after laparoscopic radical resection of gynecological malignancies, which can speed up the recovery of diseases and improve the quality of life. Thus, it is worthy of clinical application.
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The shutting effect in lithium-sulfur (Li-S) batteries hinders their widespread application, which can be restrained effectively by a modified separator. In this work, a composite of reduced graphene oxide and beta-phase TiO2 nanoparticles (RGO/TiO2(B)) is designed as a separator modification material for improving the electrochemical behavior of Li-S batteries. The TiO2(B) nanoparticles are in situ prepared and tightly adhere to the RGO layer. A series of examinations demonstrated that the RGO/TiO2(B)-coated separator efficiently inhibits the polysulfide shuttling phenomenon by the cooperative effect of physical adsorption and chemical binding. Specifically, as modified separators, a comparison between TiO2(B) and anatase TiO2(A) each composited with RGO has been conducted. The TiO2(B) sample not only exhibits a superior blocking character of migrating polysulfides, but also enhances battery electrochemical kinetics by fast Li ion diffusion.
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Three classes of red phosphorescent polymers (PF-H- x, PF-DPO- x, and PF-DPA- x, where x denotes the mole content of Ir complex) have been designed and synthesized, where the Câ§N ligand of the tethered dopant bis(2,4-diphenylquinolyl)iridium(acetylacetonate) is substituted by hydrogen (H), diphenylphosphine oxide (DPO), and diphenylamine (DPA), respectively. It is found that the electron-withdrawing DPO group can lower the lowest unoccupied molecular orbital (LUMO) level of the phosphor, whereas the electron-donating DPA group leads to an upshifted highest occupied molecular orbital (HOMO) level of the phosphor. Following a sequence of PF-DPA- x, PF-H- x, and PF-DPO- x, the electron trap depth between dopant and host is gradually up from 0.43 to 1.01 eV, and the hole trap depth is correspondingly down from 0.74 to 0.46 eV. As a result, PF-DPO- x achieves the most balanced charge transport in the emitting layer among these polymers, revealing a record-high luminous efficiency (LE) of 10.3 cd/A and Commission Internationale de L'Eclairage (CIE) coordinates of (0.62, 0.33) on the basis of the simple single-layer device structure. Compared with PF-H- x (3.8 cd/A) and PF-DPA- x (1.2 cd/A) containing the same Ir content, the significantly improved performance indicates that trap-assisted charge balance is a promising strategy to optimize the device efficiency of red phosphorescent polymers.