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1.
BMC Plant Biol ; 24(1): 202, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509479

RESUMO

BACKGROUND: Expansion and contraction of inverted repeats can cause considerable variation of plastid genomes (plastomes) in angiosperms. However, little is known about whether structural variations of plastomes are associated with adaptation to or occupancy of new environments. Moreover, adaptive evolution of angiosperm plastid genes remains poorly understood. Here, we sequenced the complete plastomes for four species of xerophytic Ceratocephala and hydrophytic Myosurus, as well as Ficaria verna. By an integration of phylogenomic, comparative genomic, and selection pressure analyses, we investigated evolutionary patterns of plastomes in Ranunculeae and their relationships with adaptation to dry and aquatic habitats. RESULTS: Owing to the significant contraction of the boundary of IRA/LSC towards the IRA, plastome sizes and IR lengths of Myosurus and Ceratocephala are smaller within Ranunculeae. Compared to other Ranunculeae, the Myosurus plastome lost clpP and rps16, one copy of rpl2 and rpl23, and one intron of rpoC1 and rpl16, and the Ceratocephala plastome added an infA gene and lost one copy of rpl2 and two introns of clpP. A total of 11 plastid genes (14%) showed positive selection, two genes common to Myosurus and Ceratocephala, seven in Ceratocephala only, and two in Myosurus only. Four genes showed strong signals of episodic positive selection. The rps7 gene of Ceratocephala and the rpl32 and ycf4 genes of Myosurus showed an increase in the rate of variation close to 3.3 Ma. CONCLUSIONS: The plastomic structure variations as well as the positive selection of two plastid genes might be related to the colonization of new environments by the common ancestor of Ceratocephala and Myosurus. The seven and two genes under positive selection might be related to the adaptation to dry and aquatic habitats in Ceratocephala and Myosurus, respectively. Moreover, intensified aridity and frequent sea-level fluctuations, as well as global cooling, might have favored an increased rate of change in some genes at about 3.3 Ma, associated with adaptation to dry and aquatic environments, respectively. These findings suggest that changing environments might have influenced structural variations of plastomes and fixed new mutations arising on some plastid genes owing to adaptation to specific habitats.


Assuntos
Genomas de Plastídeos , Ranunculaceae , Evolução Molecular , Sequência de Bases , Ranunculaceae/genética , Filogenia , Genomas de Plastídeos/genética
2.
Br J Psychiatry ; 224(5): 170-178, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38602159

RESUMO

BACKGROUND: Major depressive disorder (MDD) has been increasingly understood as a disruption of brain connectome. Investigating grey matter structural networks with a large sample size can provide valuable insights into the structural basis of network-level neuropathological underpinnings of MDD. AIMS: Using a multisite MRI data-set including nearly 2000 individuals, this study aimed to identify robust topology and connectivity abnormalities of grey matter structural network linked to MDD and relevant clinical phenotypes. METHOD: A total of 955 MDD patients and 1009 healthy controls were included from 23 sites. Individualised structural covariance networks (SCN) were established based on grey matter volume maps. Following data harmonisation, network topological metrics and focal connectivity were examined for group-level comparisons, individual-level classification performance and association with clinical ratings. Various validation strategies were applied to confirm the reliability of findings. RESULTS: Compared with healthy controls, MDD individuals exhibited increased global efficiency, abnormal regional centralities (i.e. thalamus, precentral gyrus, middle cingulate cortex and default mode network) and altered circuit connectivity (i.e. ventral attention network and frontoparietal network). First-episode drug-naive and recurrent patients exhibited different patterns of deficits in network topology and connectivity. In addition, the individual-level classification of topological metrics outperforms that of structural connectivity. The thalamus-insula connectivity was positively associated with the severity of depressive symptoms. CONCLUSIONS: Based on this high-powered data-set, we identified reliable patterns of impaired topology and connectivity of individualised SCN in MDD and relevant subtypes, which adds to the current understanding of neuropathology of MDD and might guide future development of diagnostic and therapeutic markers.


Assuntos
Transtorno Depressivo Maior , Substância Cinzenta , Imageamento por Ressonância Magnética , Humanos , Transtorno Depressivo Maior/patologia , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/fisiopatologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Masculino , Adulto , Pessoa de Meia-Idade , Conectoma , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Estudos de Casos e Controles , Neuroimagem , Adulto Jovem , Encéfalo/patologia , Encéfalo/diagnóstico por imagem , Rede de Modo Padrão/diagnóstico por imagem , Rede de Modo Padrão/patologia , Rede de Modo Padrão/fisiopatologia
3.
Cell Commun Signal ; 22(1): 91, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302953

RESUMO

Colorectal cancer (CRC) is a significant public health concern, and its development is associated with mitochondrial dysfunction. Mitochondria can adapt to the high metabolic demands of cancer cells owing to their plasticity and dynamic nature. The fusion-fission dynamics of mitochondria play a crucial role in signal transduction and metabolic functions of CRC cells. Enhanced mitochondrial fission promotes the metabolic reprogramming of CRC cells, leading to cell proliferation, metastasis, and chemoresistance. Excessive fission can also trigger mitochondria-mediated apoptosis. In contrast, excessive mitochondrial fusion leads to adenosine triphosphate (ATP) overproduction and abnormal tumor proliferation, whereas moderate fusion protects intestinal epithelial cells from oxidative stress-induced mitochondrial damage, thus preventing colitis-associated cancer (CAC). Therefore, an imbalance in mitochondrial dynamics can either promote or inhibit CRC progression. This review provides an overview of the mechanism underlying mitochondrial fusion-fission dynamics and their impact on CRC biology. This revealed the dual role of mitochondrial fusion-fission dynamics in CRC development and identified potential drug targets. Additionally, this study partially explored mitochondrial dynamics in immune and vascular endothelial cells in the tumor microenvironment, suggesting promising prospects for targeting key fusion/fission effector proteins against CRC.


Assuntos
Neoplasias Colorretais , Dinâmica Mitocondrial , Humanos , Células Endoteliais/metabolismo , Mitocôndrias/metabolismo , Transdução de Sinais , Neoplasias Colorretais/patologia , Proteínas Mitocondriais/metabolismo , Microambiente Tumoral
4.
Microb Cell Fact ; 23(1): 118, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38659044

RESUMO

BACKGROUND: Excessive alcohol consumption has been consistently linked to serious adverse health effects, particularly affecting the liver. One natural defense against the detrimental impacts of alcohol is provided by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH), which detoxify harmful alcohol metabolites. Recent studies have shown that certain probiotic strains, notably Lactobacillus spp., possess alcohol resistance and can produce these critical enzymes. Incorporating these probiotics into alcoholic beverages represents a pioneering approach that can potentially mitigate the negative health effects of alcohol while meeting evolving consumer preferences for functional and health-centric products. RESULTS: Five lactic acid bacteria (LAB) isolates were identified: Lactobacillus paracasei Alc1, Lacticaseibacillus rhamnosus AA, Pediococcus acidilactici Alc3, Lactobacillus paracasei Alc4, and Pediococcus acidilactici Alc5. Assessment of their alcohol tolerance, safety, adhesion ability, and immunomodulatory effects identified L. rhamnosus AA as the most promising alcohol-tolerant probiotic strain. This strain also showed high production of ADH and ALDH. Whole genome sequencing analysis revealed that the L. rhamnosus AA genome contained both the adh (encoding for ADH) and the adhE (encoding for ALDH) genes. CONCLUSIONS: L. rhamnosus AA, a novel probiotic candidate, showed notable alcohol resistance and the capability to produce enzymes essential for alcohol metabolism. This strain is a highly promising candidate for integration into commercial alcoholic beverages upon completion of comprehensive safety and functionality evaluations.


Assuntos
Álcool Desidrogenase , Etanol , Probióticos , Humanos , Álcool Desidrogenase/metabolismo , Álcool Desidrogenase/genética , Etanol/metabolismo , Lactobacillus/metabolismo , Lactobacillus/genética , Lactobacillales/genética , Lactobacillales/metabolismo , Lacticaseibacillus rhamnosus/genética , Lacticaseibacillus rhamnosus/metabolismo , Aldeído Oxirredutases/metabolismo , Aldeído Oxirredutases/genética , Pediococcus acidilactici/metabolismo
5.
Compr Psychiatry ; 133: 152487, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38714144

RESUMO

BACKGROUND: The incidence of non-suicidal self-injury (NSSI) has been on the rise in recent years. Studies have shown that people with NSSI have difficulties in emotion regulation and cognitive control. In addition, some studies have investigated the cognitive emotion regulation of people with NSSI which found that they have difficulties in cognitive emotion regulation, but there was a lack of research on cognitive emotion regulation strategies and related neural mechanisms. METHODS: This study included 117 people with NSSI (age = 19.47 ± 5.13, male = 17) and 84 non-NSSI participants (age = 19.86 ± 4.14, male = 16). People with NSSI met the DSM-5 diagnostic criteria, and non-NSSI participants had no mental or physical disorders. The study collected all participants' data of Cognitive Emotion Regulation Questionnaire (CERQ) and functional magnetic resonance imaging (fMRI) to explore the differences in psychological performance and brain between two groups. Afterwards, Machine learning was used to select the found differential brain regions to obtain the highest correlation regions with NSSI. Then, Allen's Human Brain Atlas database was used to compare with the information on the abnormal brain regions of people with NSSI to find the genetic information related to NSSI. In addition, gene enrichment analysis was carried out to find the related pathways and specific cells that may have differences. RESULTS: The differences between NSSI participants and non-NSSI participants were as follows: positive refocusing (t = -4.74, p < 0.01); refocusing on plans (t = -4.11, p < 0.01); positive reappraisal (t = -9.22, p < 0.01); self-blame (t = 6.30, p < 0.01); rumination (t = 3.64, p < 0.01); catastrophizing (t = 9.10, p < 0.01), and blaming others (t = 2.52, p < 0.01), the precentral gyrus (t = 6.04, pFDR < 0.05) and the rolandic operculum (t = -4.57, pFDR < 0.05). Rolandic operculum activity was negatively correlated with blaming others (r = -0.20, p < 0.05). Epigenetic results showed that excitatory neurons (p < 0.01) and inhibitory neurons (p < 0.01) were significant differences in two pathways, "trans-synaptic signaling" (p < -log108) and "modulation of chemical synaptic transmission" (p < -log108) in both cells. CONCLUSIONS: People with NSSI are more inclined to adopt non-adaptive cognitive emotion regulation strategies. Rolandic operculum is also abnormally active. Abnormal changes in the rolandic operculum of them are associated with non-adaptive cognitive emotion regulation strategies. Changes in the excitatory and inhibitory neurons provide hints to explore the abnormalities of the neurological mechanisms at the cellular level of them. Trial registration number NCT04094623.


Assuntos
Regulação Emocional , Imageamento por Ressonância Magnética , Comportamento Autodestrutivo , Humanos , Comportamento Autodestrutivo/psicologia , Comportamento Autodestrutivo/fisiopatologia , Masculino , Feminino , Regulação Emocional/fisiologia , Adulto , Adulto Jovem , Adolescente , Cognição/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Inquéritos e Questionários
6.
Appl Opt ; 63(8): 2030-2035, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38568644

RESUMO

Multimode power splitters are the fundamental building blocks in mode division multiplexing systems. In this paper, we propose a low-loss and compact, dual-mode, 3-dB power splitter for the two lowest TE modes combining three different structures, including a directional coupler, a multimode interferometer, and a Y-junction. The coupling length of the proposed device is only 7.2 µm. For both T E 0 and T E 1 modes, the numerical simulation shows that the insertion loss is only less than 0.1 dB and crosstalk is less than -20d B at the wavelength range of 1520-1580 nm. The working bandwidth can cover the entire C-band. It offers a potential solution for a 3-dB power splitter of the two lowest TE modes.

7.
Nano Lett ; 23(21): 9851-9857, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37871176

RESUMO

Constructing two-dimensional (2D) artificial superlattices based on single-atom and few-atom nanoclusters is of great interest for exploring exotic physics. Here we report the realization of two types of artificial germanium (Ge) superlattice self-confined by a 37×37 R25.3° superstructure of bismuth (Bi) induced electronic kagome lattice potential valleys. Scanning tunneling microscopy measurements demonstrate that Ge atoms prefer to be confined in the center of the Bi electronic kagome lattice, forming a single-atom superlattice at 120 K. In contrast, room temperature grown Ge atoms and clusters are confined in the sharing triangle corner and the center, respectively, of the kagome lattice potential valleys, forming an artificial honeycomb superlattice. First-principle calculations and Mulliken population analysis corroborate that our reported atomically thin Bi superstructure on Au(111) has a kagome surface potential valley with the center of the inner Bi hexagon and the space between the outer Bi hexagons being energetically favorable for trapping Ge atoms.

8.
J Environ Manage ; 366: 121793, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38991342

RESUMO

Acidic nitrification, as a novel process for treating wastewater without sufficient alkalinity, has received increasing attention over the years. In this study, a continuous-flow reactor with aerobic granular sludge was successful operated at low pH (<6.5) performing high-rate acidic nitrification. Volumetric ammonium oxidation rate of 0.4-1.2 kg/(m3·d) were achieved with the specific biomass activities of 5.8-13.9 mg N/(gVSS·h). Stable partial nitritation with nitrite accumulation efficiency over 85% could be maintained at pH above 6 with the aid of residual ammonium, whereas the nitrite accumulation disappeared when pH was below 6. Interestingly, the granule morphology significantly improved during the acidic operation. The increased secretion of extracellular polymeric substances (especially polysaccharides) suggested a self-protective behavior of microbes in the aerobic granules against acidic stress. 16S rRNA gene sequencing analyses indicated that Candidatus Nitrospira defluvii was always the dominant nitrite-oxidizing bacteria, while the dominant ammonia-oxidizing bacteria shifted from Nitrosomonas europaea to Nitrosomonas mobilis. This study, for the first time, demonstrated the improved stability of aerobic granules under acidic conditions, and also highlighted aerobic granules as a useful solution to achieve high-rate acidic nitrification.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38959946

RESUMO

BACKGROUND: The study aimed to investigate the general mental health status and its associated factors in women during late pregnancy. The objective was to provide a scientific basis for developing psychological interventions tailored to this specific population. METHODS: The research was conducted from May 2021 to July 2022, involving the recruitment of 200 women attending maternal and child health clinics for their late-pregnancy checkups. Data collection was carried out using a comprehensive approach, involving several validated tools. The participants completed a general demographic and sociological questionnaire along with four standardized psychological assessment scales: the 12-item General Health Questionnaire (GHQ-12), the Athens Insomnia Scale (AIS-8), the Generalized Anxiety Disorder 7 (GAD-7), and the 9-question Patient Health Questionnaire (PHQ-9). A total of 200 valid questionnaires were collected for analysis. RESULTS: The study revealed that the overall prevalence of positive detection of general mental health problems in women during late pregnancy was 11%. Significant differences were observed in the positive detection rate of general mental health status based on various factors such as the quality of relationships with husbands, pregnancy intentions, insomnia, anxiety, and depression (p<0.01). Furthermore, participants with general mental health problems displayed notably higher scores on the AIS-8, PHQ-9, and GAD-7 scales compared to those without such problems (p<0.01). Regression analysis indicated that pregnancy intention and PHQ-9 scores were influential factors affecting the general mental health of women during late pregnancy (p<0.05). CONCLUSION: The study highlights high rates of general mental health problems during late pregnancy, with unplanned pregnancy and elevated depression scores as key risk factors. Regular mental health screening and targeted interventions are essential to support women during this critical period and enhance the well-being of both mothers and babies.

10.
Cell Biol Toxicol ; 39(3): 1077-1098, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-34773530

RESUMO

Uterine deficiency of Dnmt3b impairs decidualization and consequent embryo implantation defects. Recent advances in molecular technologies have allowed the unprecedented mapping of epigenetic modifications during embryo implantation. DNA methyltransferase 3a (DNMT3A) and DNMT3B are responsible for establishing DNA methylation patterns produced through their de novo-type DNA methylation activity in implantation stage embryos and during germ cell differentiation. It was reported that conditional knockout of Dnmt3a in the uterus does not markedly affect endometrial function during embryo implantation, but the tissue-specific functions of Dnmt3b in the endometrium during embryo implantation remain poorly understood to investigate the role of Dnmt3b during peri-implantation period. Here, we generated Dnmt3b conditional knockout (Dnmt3bd/d) female mice using progesterone receptor-Cre mice and examined the role of Dnmt3b during embryo implantation. Dnmt3bd/d female mice exhibited compromised fertility, which was associated with defective decidualization, but not endometrial receptivity. Furthermore, results showed loss of Dnmt3b did not lead to altered genomic methylation patterns of the decidual endometrium during early pregnancy. Transcriptome sequencing analysis of uteri from day 6 pregnant mice identified phosphoglycerate kinase 1 (Pgk1) as one of the most variable genes in Dnmt3bd/d decidual endometrium. Potential roles of PGK1 in the decidualization process during early pregnancy were confirmed. Lastly, the compromised decidualization upon the downregulation of Dnmt3b could be reversed by overexpression of Pgk1. Collectively, our findings indicate that uterine deficiency of Dnmt3b impairs decidualization and consequent embryo implantation defects.


Assuntos
Decídua , Útero , Animais , Feminino , Camundongos , Gravidez , Decídua/fisiologia , Metilação de DNA/genética , Implantação do Embrião/fisiologia , Endométrio/metabolismo , DNA Metiltransferase 3B
11.
Exp Cell Res ; 418(1): 113234, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35660538

RESUMO

Recurrence and metastasis affect the survival rate of breast cancer patients. The fundamental reason lies in the lack of understanding of the mechanism of breast cancer metastasis. In this study, the proliferation, migration and invasion abilities of breast cancer cells were evaluated. The mechanism of NUPR1/TFE3 signaling pathway on autophagy-related proteins and migration-invasion-related proteins was examined in cell model in vitro. The effects of NUPR1 on malignancy formation and metastasis were investigated in vivo. We found that NUPR1 was upregulated in breast cancer cells and tissues. NUPR1 knockdown inhibited the proliferation, migration and invasion of ZR-75-30 cells and inhibited malignancy formation and metastasis in vivo. Mechanically, NUPR1 promoted autophagy by activating of TFE3 transcription, thereby regulating breast cancer metastasis. This paper indicates that NUPR1 activates autophagy through the TFE3 signaling pathway to promote breast cancer metastasis, and provides a biological basis for the intervention of blocking distant metastasis.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Neoplasias da Mama , Proteínas de Neoplasias , Autofagia/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Feminino , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo
12.
J Cell Mol Med ; 26(9): 2579-2593, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35332658

RESUMO

Melanoma is a fatal cancer with a significant feature of resistance to traditional chemotherapeutic drugs and radiotherapy. A mutation in the kinase BRAF is observed in more than 66% of metastatic melanoma cases. Therefore, there is an urgent need to develop new BRAF-mutant melanoma inhibitors. High-dose chloroquine has been reported to have antitumour effects, but it often induces dose-limiting toxicity. In this study, a series of chloroquine derivatives were synthesized, and lj-2-66 had the best activity and was selected for further investigation. Furthermore, the anti-BRAF-mutant melanoma effect and mechanism of this compound were explored. CCK-8 and colony formation assays indicated that lj-2-66 significantly inhibited the proliferation of BRAF-mutant melanoma cells. Flow cytometry revealed that lj-2-66 induced G2/M arrest in melanoma cells and promoted apoptosis. Furthermore, lj-2-66 increased the level of ROS in melanoma cells and induced DNA damage. Interestingly, lj-2-66 also played a similar role in BRAF inhibitor-resistant melanoma cells. In summary, we found a novel chloroquine derivative, lj-2-66, that increased the level of ROS in melanoma cells and induced DNA damage, thus leading to G2/M arrest and apoptosis. These findings indicated that lj-2-66 may become a potential therapeutic drug for melanoma harbouring BRAF mutations.


Assuntos
Melanoma , Proteínas Proto-Oncogênicas B-raf , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Cloroquina/farmacologia , Dano ao DNA , Resistencia a Medicamentos Antineoplásicos , Pontos de Checagem da Fase G2 do Ciclo Celular , Humanos , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/patologia , Mutação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Espécies Reativas de Oxigênio
13.
Opt Express ; 30(24): 43815-43825, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36523072

RESUMO

In recent years, high-power, tunable terahertz (THZ) radiation sources have become the key areas of research in the world. The method of THZ waves by nonlinear optical difference frequency generation (DFG) has the advantages of wide tuning, high power, room temperature operation, and compact structure. However, the conversion efficiency of the current difference frequency method is low, which needs a trade-off between conversion efficiency and tuning range. We apply the nonlinear optical cascade difference frequency conversion theory based on stimulated Raman adiabatic passage (STIRAP) and propose a theoretical scheme to generate THZ waves. Numerical simulation investigates the cascaded difference frequency process of generating THZ waves with the help of the nonlinear medium lithium niobate (LN) crystal. The theoretical analysis shows that the maximum quantum conversion efficiency from signal laser to THZ waves is 43.2 % when the wavelength of the tuned signal laser varies between 1.044 - 1.065 µm with the fixed two pump laser wavelengths constant. The tunable THZ waves of 0.48 - 5.0 THz can be obtained and the maximum output intensity of THZ waves is 2.17 MW/cm2, and the method is robust to temperature variations. It also provides a novel idea for the cascaded difference frequency generation of THZ waves.

14.
Phys Rev Lett ; 128(12): 126401, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35394312

RESUMO

Recent transport studies have demonstrated the great potential of twisted monolayer-bilayer graphene (TMBG) as a new platform to host moiré flat bands with a higher tunability than twisted bilayer graphene (TBG). However, a direct visualization of the flat bands in TMBG and its comparison with the ones in TBG remain unexplored. Here, via fabricating on a single sample with exactly the same twist angle of ∼1.13°, we present a direct comparative study between TMBG and TBG using scanning tunneling microscopy and spectroscopy. We observe a sharp density of states peak near the Fermi energy in tunneling spectroscopy, confirming unambiguously the existence of flat electronic bands in TMBG. The bandwidth of this flat-band peak is found to be slightly narrower than that of the TBG, validating previous theoretical predictions. Remarkably, by measuring spatially resolved spectroscopy, combined with continuum model calculation, we show that the flat-band states in TMBG exhibit a unique layer-resolved localization-delocalization coexisting feature, which offers an unprecedented possibility to utilize their cooperation on exploring novel correlation phenomena. Our work provides important microscopic insight of flat-band states for better understanding the emergent physics in graphene moiré systems.

15.
Phys Chem Chem Phys ; 24(30): 18427-18434, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35881619

RESUMO

Hydroxyaromatic compounds (ArOHs) have a wide range of applications in catalytic synthesis and biological processes due to their increased acidity upon photo-excitation. The proton transfer of ArOHs via the excited singlet state has been extensively studied. However, there has still been a debate on the unique type of ArOH that can undergo an ultrafast intersystem crossing. The nitro group in p-nitrophenylphenol (NO2-Bp-OH) enhances the spin-orbit coupling between excited singlet states and the triplet manifold, enabling ultrafast intersystem crossing and the formation of the long-lived lowest excited triplet state (T1) with a high yield. In this work, we used time-resolved transient absorption to investigate the excited state proton transfer of NO2-Bp-OH in its T1 state to t-butylamine, methanol, and ethanol. The T1 state of the deprotonated form NO2-Bp-O- was first observed and identified in the case of t-butylamine. Kinetic analysis demonstrates that the formation of the hydrogen-bonded complex with methanol and ethanol as proton acceptors involves their trimers. The alcohol oligomer size required in the excited state proton transfer process is dependent on the excited acidity of photoacid.


Assuntos
Aminas , Prótons , Aminas/química , Butilaminas , Etanol , Cinética , Metanol , Dióxido de Nitrogênio
16.
Fish Physiol Biochem ; 48(6): 1555-1567, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36472706

RESUMO

Energy requirements of tissues vary greatly and exhibit different mitochondrial respiratory activities with variable participation of both substrates and oxidative phosphorylation. The present study aimed to (1) compare the substrate preferences of mitochondria from different tissues and fish species with different ecological characteristics, (2) identify an appropriate substrate for comparing metabolism by mitochondria from different tissues and species, and (3) explore the relationship between mitochondrial metabolism mechanisms and ecological energetic strategies. Respiration rates and cytochrome c oxidase (CCO) activities of mitochondria isolated from heart, brain, kidney, and other tissues from Silurus meridionalis, Carassius auratus, and Megalobrama amblycephala were measured using succinate (complex II-linked substrate), pyruvate (complex I-linked), glutamate (complex I-linked), or combinations. Mitochondria from all tissues and species exhibited substrate preferences. Mitochondria exhibited greater coupling efficiencies and lower leakage rates using either complex I-linked substrates, whereas an opposite trend was observed for succinate (complex II-linked). Furthermore, maximum mitochondrial respiration rates were higher with the substrate combinations than with individual substrates; therefore, state III respiration rates measured with substrate combinations could be effective indicators of maximum mitochondrial metabolic capacity. Regardless of fish species, both state III respiration rates and CCO activities were the highest in heart mitochondria, followed by red muscle mitochondria. However, differences in substrate preferences were not associated with species feeding habit. The maximum respiration rates of heart mitochondria with substrate combinations could indicate differences in locomotor performances, with higher metabolic rates being associated with greater capacity for sustained swimming.


Assuntos
Mitocôndrias , Taxa Respiratória , Animais , Mitocôndrias/metabolismo , Coração , Succinatos/metabolismo , Consumo de Oxigênio
17.
Hepatology ; 72(1): 169-182, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31677282

RESUMO

BACKGROUND AND AIMS: Free and bioavailable 25-hydroxyvitamin D (25OHD) are emerging measurements of vitamin D status. It remains unclear whether circulating free or bioavailable 25OHD are relevant to hepatocellular carcinoma (HCC) prognosis. Our aim was to test the hypothesis that bioavailable 25OHD may be a better serum biomarker of vitamin D status than total 25OHD on the association with HCC survival. APPROACH AND RESULTS: We included 1,031 newly diagnosed, previously untreated patients with HCC from the Guangdong Liver Cancer Cohort enrolled between September 2013 and April 2017. Serum total 25OHD levels were measured using an electrochemiluminescence immunoassay. Serum-free 25OHD levels were measured using a two-step enzyme-linked immunosorbent assay. Bioavailable 25OHD levels were calculated from measured free 25OHD and albumin using a previously validated equation. Primary outcomes were liver cancer-specific (LCSS) and overall survival (OS). Cox proportional hazards models were performed to calculate the multivariable hazard ratios (HRs) and 95% confidence intervals (CIs). During a median follow-up of 726 days, 430 patients had deceased, including 393 deaths from HCC. In multivariable analyses, higher bioavailable 25OHD levels were significantly associated with better survival, independent of nonclinical and clinical prognostic factors including serum C-reactive protein, Barcelona Clinic Liver Cancer stage, and cancer treatment. The multivariable-adjusted HRs in the highest versus lowest quartile of bioavailable 25OHD levels were 0.69 (95% CI: 0.51, 0.93; P for trend = 0.014) for LCSS and 0.71 (95% CI: 0.53, 0.94; P for trend = 0.013) for OS. In contrast, neither total nor free 25OHD levels were associated with LCSS or OS. CONCLUSIONS: Higher bioavailable, rather than total, 25OHD levels were independently associated with improved survival in a population-based HCC cohort, suggesting a potential utility of bioavailable 25OHD in HCC prognosis.


Assuntos
Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Vitamina D/análogos & derivados , Adulto , Idoso , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida , Vitamina D/sangue
18.
Reproduction ; 162(6): 449-460, 2021 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-34718231

RESUMO

The nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome plays a critical role in various inflammatory diseases. We sought to investigate the role of NLRP3 inflammasome in uterine activation for labor at term and preterm. We found that NLRP3 inflammasome was activated in the myometrium tissues obtained from the pregnant women undergoing labor at term (TL) compared with those not undergoing labor (TNL) at term. NLRP3 inflammasome was also activated in amnion and chorion-deciduas in TL and preterm labor (PTL) groups. In the mouse model, uterine NLRP3 inflammasome and nuclear factor kappaB (NF-κB) were activated toward term and during labor. Treatment of pregnant mice with lipopolysaccharide (LPS) and RU38486 induced preterm birth (PTB) and also promoted uterine NLRP3 inflammasome and NF-κB activation. Treatment of pregnant mice with NLRP3 inflammasome inhibitor BAY11-7082 and MCC950 delayed the onset of labor and suppressed NLRP3 inflammasome and NF-κB activation in uterus. MCC950 postponed labor onset of the mice with LPS and RU38486 treatment and inhibited NLRP3 inflammasome activation in uterus. Our data provide the evidence that NLRP3 inflammasome is involved in uterine activation for labor onset in term and PTB in humans and mouse model.


Assuntos
Inflamassomos , Nascimento Prematuro , Animais , Feminino , Humanos , Recém-Nascido , Camundongos , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Gravidez , Útero/metabolismo
19.
FASEB J ; 34(3): 4702-4717, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32030825

RESUMO

Serine has critical roles in maintaining cell growth and redox balance in cancer cells. However, the role of exogenous serine played in oxidative response and proliferation in normal mammalian intestine need to be further elucidated. We used a mouse model and intestinal porcine epithelial cells (IPEC-J2) to reveal that exogenous serine deficiency did not lead to redox imbalance and inhibition of proliferation in the intestine. However, serine deficiency exacerbated oxidative stress, mitochondrial dysfunction, apoptosis, and inhibition of proliferation in IPEC-J2 cells challenged by hydrogen peroxide, while serine supplementation rescued redox imbalance and those proliferation defects. Importantly, serine supplementation restored the glutathione content and decreased the accumulation of reactive oxygen species, while no such effects were observed when glutathione synthesis was inhibited. Additionally, serine supplementation increased nuclear nrf2 expression in IPEC-J2 cells. These results suggested that serine alleviates oxidative stress through supporting glutathione synthesis and activating nrf2 signaling. We further found that serine supplementation activated the mTOR pathway, while inhibition of mTOR diminished the effects of serine on promoting proliferation, suggesting critical roles of the mTOR pathway in this context. Taken together, our study underlines the importance of serine in the maintenance of redox status and proliferation in the intestine and reveals a novel potential mechanism that mediates these effects.


Assuntos
Proliferação de Células/fisiologia , Serina/metabolismo , Animais , Ciclo Celular/fisiologia , Linhagem Celular , Sobrevivência Celular/fisiologia , Peroxidase de Eosinófilo/metabolismo , Glutationa/metabolismo , Mucosa Intestinal/metabolismo , L-Lactato Desidrogenase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Transdução de Sinais , Suínos , Serina-Treonina Quinases TOR/metabolismo
20.
Br J Nutr ; 126(7): 1091-1099, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33308344

RESUMO

The association between dietary Fe intake and diabetes risk remains inconsistent. We aimed to explore the association between dietary Fe intake and type 2 diabetes mellitus (T2DM) risk in middle-aged and older adults in urban China. This study used data from the Guangzhou Nutrition and Health Study, an on-going community-based prospective cohort study. Participants were recruited from 2008 to 2013 in Guangzhou community. A total of 2696 participants aged 40-75 years without T2DM at baseline were included in data analyses, with a median of 5·6 (interquartile range 4·1-5·9) years of follow-up. T2DM was identified by self-reported diagnosis, fasting glucose ≥ 7·0 mmol/l or glycosylated Hb ≥ 6·5 %. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95 % CI. We ascertained 205 incident T2DM cases during 13 476 person-years. The adjusted HR for T2DM risk in the fourth quartile of haem Fe intake was 1·92 (95 % CI 1·07, 3·46; Ptrend = 0·010), compared with the first quartile intake. These significant associations were found in haem Fe intake from total meat (HR 2·74; 95 % CI 1·22, 6·15; Ptrend = 0·011) and haem Fe intake from red meat (HR 1·86; 95 % CI 1·01, 3·44; Ptrend = 0·034), but not haem Fe intake from processed meat, poultry or fish/shellfish. The association between dietary intake of total Fe or non-haem Fe with T2DM risk had no significance. Our findings suggested that higher dietary intake of haem Fe (especially from red meat), but not total Fe or non-haem Fe, was associated with greater T2DM risk in middle-aged and older adults.


Assuntos
Diabetes Mellitus Tipo 2 , Dieta , Ferro da Dieta , Adulto , Idoso , China/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etiologia , Heme , Humanos , Ferro da Dieta/administração & dosagem , Pessoa de Meia-Idade , Estudos Prospectivos , Carne Vermelha , Fatores de Risco
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