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Alternative pre-mRNA-splicing-induced post-transcriptional gene expression regulation is one of the pathways for tumors maintaining proliferation rates accompanying the malignant phenotype under stress. Here, we uncover a list of hyperacetylated proteins in the context of acutely reduced Acetyl-CoA levels under nutrient starvation. PHF5A, a component of U2 snRNPs, can be acetylated at lysine 29 in response to multiple cellular stresses, which is dependent on p300. PHF5A acetylation strengthens the interaction among U2 snRNPs and affects global pre-mRNA splicing pattern and extensive gene expression. PHF5A hyperacetylation-induced alternative splicing stabilizes KDM3A mRNA and promotes its protein expression. Pathologically, PHF5A K29 hyperacetylation and KDM3A upregulation axis are correlated with poor prognosis of colon cancer. Our findings uncover a mechanism of an anti-stress pathway through which acetylation on PHF5A promotes the cancer cells' capacity for stress resistance and consequently contributes to colon carcinogenesis.
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Processamento Alternativo , Carcinogênese/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Histona Desmetilases com o Domínio Jumonji/genética , Proteínas de Ligação a RNA/genética , Transativadores/genética , Acetilcoenzima A/deficiência , Acetilação , Animais , Carcinogênese/metabolismo , Carcinogênese/patologia , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Células HCT116 , Humanos , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Histona Desmetilases com o Domínio Jumonji/metabolismo , Células MCF-7 , Masculino , Camundongos , Camundongos Nus , Prognóstico , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteína Nuclear Pequena U2/genética , Ribonucleoproteína Nuclear Pequena U2/metabolismo , Transdução de Sinais , Análise de Sobrevida , Transativadores/antagonistas & inibidores , Transativadores/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Fatores de Transcrição de p300-CBP/genética , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
Mutations that occur in RNA-splicing machinery may contribute to hematopoiesis-related diseases. How splicing factor mutations perturb hematopoiesis, especially in the differentiation of erythro-myeloid progenitors (EMPs), remains elusive. Dhx38 is a pre-mRNA splicing-related DEAH box RNA helicase, for which the physiological functions and splicing mechanisms during hematopoiesis currently remain unclear. Here, we report that Dhx38 exerts a broad effect on definitive EMPs as well as the differentiation and maintenance of hematopoietic stem and progenitor cells (HSPCs). In dhx38 knockout zebrafish, EMPs and HSPCs were found to be arrested in mitotic prometaphase, accompanied by a 'grape' karyotype, owing to the defects in chromosome alignment. Abnormal alternatively spliced genes related to chromosome segregation, the microtubule cytoskeleton, cell cycle kinases and DNA damage were present in the dhx38 mutants. Subsequently, EMPs and HSPCs in dhx38 mutants underwent P53-dependent apoptosis. This study provides novel insights into alternative splicing regulated by Dhx38, a process that plays a crucial role in the proliferation and differentiation of fetal EMPs and HSPCs.
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Processamento Alternativo , Peixe-Zebra , Processamento Alternativo/genética , Animais , Hematopoese/genética , Células-Tronco Hematopoéticas , Células Progenitoras Mieloides , Peixe-Zebra/genética , Peixe-Zebra/metabolismoRESUMO
BACKGROUND: The causal nature of gut microbiota and cerebral small vessel disease (CSVD) is still obscure regardless of evidence supporting their observational correlations. OBJECTIVES: The primary objective of this research is to investigate the potentially pathogenic or protective causal impacts of specific gut microbiota on various neuroimaging subtypes of CSVD. METHODS: We obtained the latest summary-level genome-wide databases for gut microbiota and 9 CSVD traits. The univariable and multivariable Mendelian randomization (MR) studies were conducted to examine the possible causal link between exposure and outcome. Meanwhile, we conducted sensitivity analyses sequentially, containing the heterogeneity, pleiotropy, and leave-one-out analysis. Additionally, to clarify the potential bidirectional causality, the causality from CSVD traits to the identified gut microbiota was implemented through reverse MR analysis. RESULTS: The univariable MR analysis identified 22 genetically predicted bacterial abundances that were correlated with CSVD traits. Although conditioning on macronutrient dietary compositions, 2 suggestive relationships were retained using the multivariable MR analysis. Specifically, the class Negativicutes and order Selenomonadales exhibited a negative causal association with strictly lobar cerebral microbleeds, one neuroimaging trait of CSVD. There is insufficient evidence indicating the presence of heterogeneity and horizontal pleiotropy. Furthermore, the identified causal relationship was not driven by any single nucleotide polymorphism. The results of the reverse MR analysis did not reveal any statistically significant causality from CSVD traits to the identified gut microbiota. CONCLUSIONS: Our study indicated several suggestive causal effects from gut microbiota to different neuroimaging subtypes of CSVD. These findings provided a latent understanding of the pathogenesis of CSVD from the perspective of the gut-brain axis.
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Doenças de Pequenos Vasos Cerebrais , Microbioma Gastrointestinal , Análise da Randomização Mendeliana , Doenças de Pequenos Vasos Cerebrais/genética , Doenças de Pequenos Vasos Cerebrais/microbiologia , Humanos , Estudo de Associação Genômica AmplaRESUMO
BACKGROUND: Process approach is valuable for memory assessment in Alzheimer's disease (AD) and mild cognitive impairment (MCI), yet its underlying mechanisms remain elusive. This study aims to synergize the process approach with brain structure analysis to explore both the discriminative capacity and potential mechanisms underlying the process approach. METHODS: 37 subjects of MCI, 35 subjects of AD and 38 subjects of healthy control (HC) were included. The process approach in Auditory Verbal Learning Test (AVLT), including discriminability (A'), response bias (B"D), semantic clustering (LBCsem) and serial clustering (LBCser) was performed. The gray matter volume (GMV) was analyzed by voxel-based morphometry. Receiver operating characteristic (ROC) analysis and partial correlations were conducted to explore the value of the process approach and investigate the relationship between the process approach, traditional indices of AVLT and GMV. RESULTS: ROC analysis showed the value of A', B"D and LBCser in differentiating MCI and AD. Combining AVLT-Immediately Recall (AVLT-IR) and LBCser showed a higher value in diagnosing MCI. Partial correlations revealed that in the MCI group, A' and B"D were mainly positively associated with GMV of the hippocampus and temporal lobe. CONCLUSION: This study indicated that the process approach is a promising cognitive biomarker to detect MCI and AD.
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Doença de Alzheimer , Biomarcadores , Disfunção Cognitiva , Substância Cinzenta , Imageamento por Ressonância Magnética , Humanos , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Doença de Alzheimer/diagnóstico , Masculino , Feminino , Idoso , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Testes Neuropsicológicos/estatística & dados numéricosRESUMO
The key to searching novel nonlinear optical (NLO) crystals was effectively combining the NLO-active units to obtain a noncentrosymmetric structure. Nevertheless, the present predicament lies in the growing challenge of discovering novel crystals within conventional inorganic frameworks that surpass the properties of the current NLO materials. In view of this, researchers expanded their research focus to the organic-inorganic hybridization system; it is foreseeable to concentrate the advantages from several kinds of NLO-active units to acquire novel NLO crystals with superior properties. We herein report an organic-inorganic hybrid molybdate crystal, namely, [C(NH2)3]6Mo7O24 (GMO). It was successfully obtained via combining inorganic NLO-active MoO6 octahedra and organic π-conjugated [C(NH2)3]+ groups. GMO demonstrates a moderate second-harmonic-generation response, specifically measuring about 1.3 times the value of KDP. Additionally, it exhibits a significant birefringence value of 0.203 at the wavelength of 550 nm and possesses a wide band gap of 3.31 eV. Theoretical calculations suggest that the optical properties of the GMO are primarily influenced by the synergy effect of [C(NH2)3]+ groups between MoO6 octahedra.
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We herein report an unprecedented organic-inorganic hybrid borate incorporating a novel nonlinear-optical (NLO) active unit, namely, [C(NH2)3][B(C2O2H4)2]. The novel NLO active unit was derived from the condensation reaction between two glycol molecules and one (BO4)5- group. The title compound exhibits a moderate second-harmonic-generation effect (0.7 × KDP), a significant band gap (5.76 eV), and a suitable birefringence (0.078 at 550 nm). The optical properties are determined by the synergistic interaction between the C(NH2)3+ cation and the [B(C2O2H4)2]- group, as indicated by theoretical calculations.
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White matter hyperintensities (WMHs) of presumed vascular origin are important imaging biomarkers of cerebral small vessel disease (CSVD). Previous studies have verified abnormal functional brain networks in CSVD. However, most of these studies rely on static functional connectivity, and only a few focus on the varying severity of the WMHs. Hence, our study primarily explored the disrupted dynamic functional network connectivity (dFNC) and topological organization variance in patients with WMHs. This study included 38 patients with moderate WMHs, 47 with severe WMHs, and 68 healthy controls (HCs). Ten independent components were chosen using independent component analysis based on resting-state functional magnetic resonance imaging. The dFNC of each participant was estimated using sliding windows and k-means clustering. We identified three reproducible dFNC states. Among them, patients with WMHs had a significantly higher occurrence in the sparsely connected State 1, but a lower occurrence and shorter duration in the positive and stronger connected State 3. Regarding topological organization variance, patients with WMHs showed higher variance in local efficiency but not global efficiency compared to HCs. Among the WMH subgroups, patients with severe WMHs showed similar but more obvious alterations than those with moderate WMHs. These altered network characteristics indicated an imbalance between the functional segregation and integration of brain networks, which was correlated with global cognition, memory, executive functions, and visuospatial abilities. Our study confirmed aberrant dFNC state metrics and topological organization variance in patients with moderate-to-severe WMHs; thus, it might provide a new pathway for exploring the pathogenesis of cognitive impairment.
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Substância Branca , Humanos , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Imageamento por Ressonância Magnética/métodos , Encéfalo/patologia , Cognição , Função ExecutivaRESUMO
MAIN CONCLUSIONS: STD1 specifically interacts with MAP65-5 in rice and they cooperatively control microtubule bundles in phragmoplast expansion during cell division. Microtubules play critical roles during the cell cycle progression in the plant cell. We previously reported that STEMLESS DWARF 1 (STD1), a kinesin-related protein, was localized specifically to the phragmoplast midzone during telophase to regulate the lateral expansion of phragmoplast in rice (Oryza sativa). However, how STD1 regulates microtubule organization remains unknown. Here, we found that STD1 interacted directly with MAP65-5, a member of the microtubule-associated proteins (MAPs). Both STD1 and MAP65-5 could form homodimers and bundle microtubules individually. Compared with MAP65-5, the microtubules bundled by STD1 were disassembled completely into single microtubules after adding ATP. Conversely, the interaction of STD1 with MAP65-5 enhanced the microtubule bundling. These results suggest STD1 and MAP65-5 might cooperatively regulate microtubule organization in the phragmoplast at telophase.
Assuntos
Proteínas Associadas aos Microtúbulos , Oryza , Proteínas Associadas aos Microtúbulos/genética , Cinesinas , Microtúbulos , MitoseRESUMO
Herein, we report an unprecedented asymmetric guanidinium polyiodate, namely, C(NH2)3(I3O8)(HI3O8)(H2I2O6)(HIO3)4·3H2O (1). The title compound was obtained via the hybridization of polyiodate anions and planar π-conjugated C(NH2)3+; meanwhile, its strong second-harmonic-generation (SHG) response (2.1 × KDP, where KDP = KH2PO4) and wide band gap (3.89 eV) were mainly dominated by the synergy effect of the aforementioned structural units.
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We herein report a mixed organic cationic hybrid nitrate, namely, [C(NH2)2NHNO2][C(NH2)3](NO3)2 (1). It was successfully achieved via combining three different planar groups: [(C(NH2)2NHNO2]+, C(NH2)3+, and NO3-. First-principles calculations confirm that the [(C(NH2)2NHNO2]+ group is an excellent cationic nonlinear-optical (NLO)-active unit. The title compound exhibits a moderate second-harmonic-generation (SHG) response (1.5 × KDP), a wide band gap (3.58 eV), and a suitable birefringence of 0.071 at 550 nm. Theoretical calculations indicate that the synergy effect between the [(C(NH2)2NHNO2]+ and C(NH2)3+ groups dominates the SHG process.
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BACKGROUND: CircZBTB46 has been identified as being associated with the risk of coronary artery disease (CAD) and has the potential to be a diagnostic biomarker for CAD. However, the specific function and detailed mechanism of circZBTB46 in CAD are still unknown. METHODS: The expression levels and properties of circRNAs were examined using qRTâPCR, RNA FISH, and subcellular localization analysis. ApoE-/- mice fed a high-fat diet were used to establish an atherosclerosis model. HE, Masson, and Oil Red O staining were used to analyze the morphological features of the plaque. CCK-8, Transwell, and wound healing assays, and flow cytometric analysis were used to evaluate cell proliferation, migration, and apoptosis. RNA pull-down, silver staining, mass spectrometry analysis, and RNA-binding protein immunoprecipitation (RIP) were performed to identify the interacting proteins of circZBTB46. RESULTS: CircZBTB46 is highly conserved and is significantly upregulated in atherosclerotic lesions. Functional studies revealed that knockdown of circZBTB46 significantly decreased the atherosclerotic plaque area, attenuating the progression of atherosclerosis. In addition, silencing circZBTB46 inhibited cell proliferation and migration and induced apoptosis. Mechanistically, circZBTB46 physically interacted with hnRNPA2B1 and suppressed its degradation, thereby regulating cell functions and the formation of aortic atherosclerotic plaques. Additionally, circZBTB46 was identified as a functional mediator of PTEN-dependent regulation of the AKT/mTOR signaling pathway and thus affected cell proliferation and migration and induced apoptosis. CONCLUSION: Our study provides the first direct evidence that circZBTB46 functions as an important regulatory molecule for CAD progression by interacting with hnRNPA2B1 and regulating the PTEN/AKT/mTOR pathway.
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Citrate synthase (CS), the rate-limiting enzyme in the tricarboxylic acid (TCA) cycle catalyzes the first step of the cycle, namely, the condensation of oxaloacetate and acetyl-CoA to produce citrate. The expression and enzymatic activity of CS are altered in cancers, but posttranslational modification (PTM) of CS and its regulation in tumorigenesis remain largely obscure. SIRT5 belongs to the nicotinamide adenine dinucleotide (NAD)+-dependent deacetylase sirtuin family and plays vital roles in multiple biological processes via modulating various substrates. Here, we show that SIRT5 interacts with CS and that SIRT5 desuccinylates CS at the evolutionarily conserved residues K393 and K395. Moreover, hypersuccinylation of CS at K393 and K395 dramatically reduces its enzymatic activity and suppresses colon cancer cell proliferation and migration. These results provide experimental evidence in support of a potential therapeutic approach for colon cancer.
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Citrato (si)-Sintase/metabolismo , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Sirtuínas/metabolismo , Movimento Celular/fisiologia , Proliferação de Células , Neoplasias do Colo/enzimologia , HumanosRESUMO
Tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) plays a critical role in regulating cell survival, cell growth, and proliferation by antagonizing the PI3K-AKT-mTOR pathway. The regulatory mechanism of PTEN protein is still not completely understood. Here, we found that Sirtuin 4 (SIRT4) interacts with PTEN and regulates its stability. Overexpression of SIRT4 in cells causes down-regulation of PTEN. This regulation is independent of PTEN acetylation and ubiquitination. We further found that SIRT4 degrades PTEN through lysosome pathway mediated by insulin degrading enzyme (IDE). SIRT4 bridges PTEN and IDE for degradation in response to nutritional starvation stresses. Our results suggest that when cells were exposed to nutritional starvation, SIRT4 was induced and cooperated with IDE to degrade PTEN; low levels of PTEN promote cells to survive from cellular stress. Our findings provide a new regulation of PTEN in response to cellular stresses.-Liu, M., Wang, Z., Ren, M., Yang, X., Liu, B., Qi, H., Yu, M., Song, S., Chen, S., Liu, L., Zhang, Y., Zou, J., Zhu, W.-G., Yin, Y., Luo, J. SIRT4 regulates PTEN stability through IDE in response to cellular stresses.
Assuntos
Insulisina/metabolismo , Proteínas Mitocondriais/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Sirtuínas/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Regulação para Baixo/fisiologia , Células HEK293 , Humanos , Células MCF-7 , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismoRESUMO
The Phytotoxicity of and mechanism underlying selenite-mediated tolerance to Cd stress in Typha angustifolia were studied hydroponically with respect to metal uptake and translocation, photosynthesis-related parameters, contents of proline and O2â¢-, products of lipid peroxidation, cell viability, enzymatic and non-enzymatic antioxidants, glyoxalases and phytochelatins. T. angustifolia were exposed to 25, 50 and 100 µM of Cd alone and in conjunction with 5 mg L-1 of selenite in full-strength Hoagland's nutrient solution for 30 days. Results showed that Cd contents in T. angustifolia leaves and roots increased in a dose-dependent manner and were higher in roots, but those of BAC, BCF and TF changed in a contrary pattern. Addition of selenite to Cd-containing treatments further reduced Cd levels in T. angustifolia leaves and roots, as well as BAC, BCF and TF. A diphasic effect was found in T. angustifolia for the contents of total chlorophyll, GSH, PC and GSSG, as well as activities of CAT, POD, SOD and GR, in response to Cd stress alone and in conjunction with selenite supplementation, but the same effect was not observed for Pn, Cond, Tr, Ci, Fv/Fm and ÏPSII. In contrast, exogenous selenite supplementation enhanced the contents of total chlorophyll and the non-enzymatic antioxidants, as well as activities of enzymatic antioxidants, while the values of photosynthetic fluorescence parameters were rescued. Selenite addition decreased Cd-induced cell death. Proline contents and Gly I activities in T. angustifolia leaves kept increasing in a dose-dependent manner of Cd concentrations in the growth media and selenite addition further enhanced both parameters. Addition of selenite could quench Cd-mediated generation of MDA, O2â¢- and MG in T. angustifolia leaves and reduce Cd-induced Gly II activity. A U-shaped GSH/GSSG ratio in T. angustifolia leaves suggests a possible trade-off between PC synthesis and GR activity since both share the same substrate GSH. Therefore, confined BAC, BCF and TF were a mechanism that confers T. angustifolia tolerance to Cd stress, and that exogenous selenite supplementation could depress Cd-induced stress in T. angustifolia by rescuing the photosynthetic fluorescence, enhancing non-enzymatic and enzymatic antioxidants that scavenge O2â¢- and MG, and potentiating PC synthesis that chelates Cd.
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Cádmio/toxicidade , Ácido Selenioso/farmacologia , Typhaceae/efeitos dos fármacos , Antioxidantes/metabolismo , Cádmio/metabolismo , Clorofila/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fitoquelatinas/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Prolina/metabolismo , Typhaceae/metabolismoRESUMO
Serine-threonine kinase receptor-associated protein (STRAP) functions as a regulator of both TGF-ß and p53 signaling that participates in the regulation of cell proliferation and cell death in response to various stresses. Here, we demonstrate that STRAP acetylation plays an important role in p53-mediated cell cycle arrest and apoptosis. STRAP is acetylated at lysines 147, 148, and 156 by the acetyltransferases CREB-binding protein (CBP) and that the acetylation is reversed by the deacetylase sirtuin7 (SIRT7). Hypo- or hyperacetylation mutations of STRAP at lysines 147, 148, and 156 (3KR or 3KQ) influence its activation and stabilization of p53. Moreover, following 5-fluorouracil (5-FU) treatment, STRAP is mobilized from the cytoplasm to the nucleus and promotes STRAP acetylation. Our finding on the regulation of STRAP links p53 with SIRT7 influencing p53 activity and stability.
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Proteínas de Ligação a RNA/metabolismo , Sirtuínas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Acetilação/efeitos dos fármacos , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Fluoruracila/farmacologia , Células HCT116 , Humanos , Lisina/metabolismo , Estabilidade Proteica , Proteínas de Ligação a RNA/genética , Sirtuínas/genética , Proteína Supressora de Tumor p53/genéticaRESUMO
Butyric acid fermentation by Clostridium couples with the synthesis of acetic acid. But the presence of acetic acid reduces butyric acid yield and increases separation and purification costs of butyric acid. Hence, enhancing the butyrate/acetate ratio is important for economical butyric acid production. This study indicated that enhancing the acetyl-CoA to butyrate flux by overexpression of both the butyryl-CoA/acetate CoA transferase (cat1) and crotonase (crt) genes in C. tyrobutyricum could significantly reduce acetic acid concentration. Fed-batch fermentation of ATCC 25755/cat1 + crt resulted in increased butyrate/acetate ratio of 15.76 g/g, which was 2.24-fold higher than that of the wild-type strain. Furthermore, in order to simultaneously increase the butyrate/acetate ratio, butyric acid concentration and productivity, the recombinant strain ATCC 25755/ppcc (co-expression of 6-phosphofructokinase (pfkA) gene, pyruvate kinase (pykA) gene, cat1, and crt) was constructed. Consequently, ATCC 25755/ppcc produced more butyric acid (46.8 vs. 35.0 g/L) with a higher productivity (0.83 vs. 0.49 g/L·h) and butyrate/acetate ratio (13.22 vs. 7.22 g/g) as compared with the wild-type strain in batch fermentation using high glucose concentration (120 g/L). This study demonstrates that enhancing the acetyl-CoA to butyrate flux is an effective way to reduce acetic acid production and increase butyrate/acetate ratio.
Assuntos
Ácido Butírico/metabolismo , Clostridium tyrobutyricum/genética , Clostridium tyrobutyricum/metabolismo , Engenharia Metabólica , Acetato-CoA Ligase/metabolismo , FermentaçãoRESUMO
It is still a challenge to explore the orientation and location of chemical groups in the two-dimensional derivative of graphene. In this study, polarized attenuated total reflectance Fourier transform infrared spectroscopy (polarized ATR-FTIR) was employed to investigate the orientation and location of C-F groups in the corresponding graphene derivative sheets, which facilitates building a relationship between the bonding nature and fine structure. There were two types of C-F bonding, (C-F)I and (C-F)II, in fluorinated graphene sheets. It was found that (C-F)II bonds were linked at the coplanar carbon atoms in the weakly fluorinated region (CxF, x ≥ 2), whereas the (C-F)I bonds cluster at the strongly deformed carbon framework with a F/C ratio of about 1. The thermostability of (C-F)II is lower than that of (C-F)I bonds. This is because the coplanar structure of the weakly fluorinated region tends to transform to the planar aromatic ring with the breaking of the C-F bond as compared with the strong fluorinated nonplanar region.
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The effect of solvent on the chemical structure and properties of fluorinated graphene (FG) was particularly investigated in this work. It is found that the reduction of FG and the weakening of strong covalent C-F bonding take place under the action of some dipolar solvents even at room temperature. The rate of the C-F bond rupture reaction is positively influenced by the dipole moment of solvent and fluorine coverage of FG sheets. Meanwhile, defluorination of FG is controllable through the time and temperature of solvent treatment. These solvents function as the nucleophilic catalysts, promoting chemical transformation, which leads to a series of changes in the structure and properties of FG, such as a decline of fluorine concentration of about 40% and the reduction of thermal stability and band gap from 3 to 2 eV. After the treatment with dipolar solvent N-methyl-2-pyrrolidinone, FG maintained a capacity of 255 mA h g(-1) and a power density of 2986 W kg(-1) at a high discharge rate, while the pristine FG could not be discharged at all. This is called the "solvent activation" effect on the electrochemical performance of FG. The finding may draw attention to the effect of various external factors on the chemical structure and properties of FG, which is of great importance for the realization of the FG's potential.
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The effect of ultraviolet irradiation on fluorinated graphene (FG) dispersed in toluene was investigated for the first time. The chemical and physical characteristics of FG before and after ultraviolet irradiation were analyzed by UV-vis, FTIR, XPS,EDS, oxygen flask combustion (OFC), XRD, TGA, Raman, SEM, TEM and fluorescence spectroscopy. It is found that the F/C ratio initially decreases rapidly and then slowly with irradiation time, finally to 0.179 after irradiation for 48 h. The nature of partial C-F bonds transforms from covalent to "semi-covalent" bonding in the process of irradiation. The restoration of new sp(2) clusters is fast at the early stage within 6 h of irradiation, promoting the structural rearrangement. The morphology of irradiated fluorinated graphene (iFG) is not significantly destroyed by ultraviolet while more overlapped sheets are formed due to quick defluorination. Photoluminescence (PL) properties show that "blue emission" located at 432 nm is enhanced due to the recovery of sp(2) domains. In particular, compared to non-aromatic solvents, there is a "synergistic effect" between aromatic solvents and ultraviolet in the defluorination process. FG is unstable and shows some structural transformations under ultraviolet irradiation, which can be used to tune its structure and properties.
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BACKGROUND: The incidence of coronary heart disease (CHD) in youth is rapidly increasing but difficultly recognized in the early stage. METHODS AND RESULTS: In this retrospective study, 194 CHD patients under the age of 45 who previously experienced chest pain symptoms and 170 non-CHD patients were included and demographic data were collected. Systemic inflammation index (SII) and systemic inflammation response index (SIRI) were increased in young CHD patients (p < 001). Spearman's correlation analysis showed that both SII and SIRI were negatively correlated with HDL and positively correlated with hypertension, Gensini score, and hsTnI. Logistic regression analysis indicated that SII and SIRI were independently associated with the presence of CHD in youth with chest pain symptoms. The area under the ROC curve (AUC) of the SII model for young CHD patients was 0.805 (0.728-0.869), and the sensitivity and specificity were 0.65 and 0.823, respectively. Meanwhile, the AUC for the SIRI model was 0.812 (0.739-0.872), and the sensitivity and specificity were 0.673 and 0.8022. The calibration curves of both SII and SIRI models are in good agreement with the actual curves. And the decision curves of both models indicated their clinical practicality. CONCLUSION: SII and SIRI are independent risk factors for CHD in young adults, which can quickly and effectively identify CHD patients among young adults who have previously experienced chest pain symptoms.