Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 661
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38970382

RESUMO

OBJECTIVES: To evaluate the impact of previous cardiac surgery (PCS) on clinical outcomes after reoperative extended arch repair for acute type A aortic dissection (ATAAD). METHODS: This study included 37 ATAAD patients with PCS (PCS group) and 992 without PCS (no-PCS group). Propensity score-matching yielded a subgroup of 36 pairs (1:1). In-hospital outcomes and mid-term survival were compared between the two groups. RESULTS: The PCS group was older (56.7 ± 14.2 vs 52.2 ± 12.6 years, p = 0.036) and underwent a longer cardiopulmonary bypass (median, 212 vs 183 min, p < 0.001) compared with the no-PCS group. Operative death occurred in 88 (8.6%) patients, exhibiting no significant difference between groups (13.5% vs 8.4%, p = 0.237). Major postoperative morbidity was observed in 431 (41.9%) patients, also showing no difference between groups (45.9% vs 41.7%, p = 0.615). Moreover, the multivariable logistic regression analysis revealed that PCS was not significantly associated with operative mortality (adjusted odds ratio [OR] 2.58, 95% confidence interval [CI] 0.91-7.29, p = 0.075) or major morbidity (adjusted OR 1.92, 95% CI 0.88-4.18, p = 0.101). The 3-year cumulative survival rates were 71.1% for the PCS group and 83.9% for the no-PCS group (log-rank p = 0.071). Additionally, Cox regression indicated that PCS was not significantly associated with midterm mortality (adjusted hazard ratio 1.40, 95% CI 0.44-4.41, p = 0.566). After matching, no significant differences were found between groups in terms of operative mortality (p > 0.999), major morbidity (p > 0.999), and midterm survival (p = 0.564). CONCLUSIONS: No significant differences were found between ATAAD patients with PCS and those without PCS regarding in-hospital outcomes and midterm survival after extended arch repair.

2.
Microbiome ; 12(1): 121, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38970122

RESUMO

BACKGROUND: Despite rapid advances in genomic-resolved metagenomics and remarkable explosion of metagenome-assembled genomes (MAGs), the function of uncultivated anaerobic lineages and their interactions in carbon mineralization remain largely uncertain, which has profound implications in biotechnology and biogeochemistry. RESULTS: In this study, we combined long-read sequencing and metatranscriptomics-guided metabolic reconstruction to provide a genome-wide perspective of carbon mineralization flow from polymers to methane in an anaerobic bioreactor. Our results showed that incorporating long reads resulted in a substantial improvement in the quality of metagenomic assemblies, enabling the effective recovery of 132 high-quality genomes meeting stringent criteria of minimum information about a metagenome-assembled genome (MIMAG). In addition, hybrid assembly obtained 51% more prokaryotic genes in comparison to the short-read-only assembly. Metatranscriptomics-guided metabolic reconstruction unveiled the remarkable metabolic flexibility of several novel Bacteroidales-affiliated bacteria and populations from Mesotoga sp. in scavenging amino acids and sugars. In addition to recovering two circular genomes of previously known but fragmented syntrophic bacteria, two newly identified bacteria within Syntrophales were found to be highly engaged in fatty acid oxidation through syntrophic relationships with dominant methanogens Methanoregulaceae bin.74 and Methanothrix sp. bin.206. The activity of bin.206 preferring acetate as substrate exceeded that of bin.74 with increasing loading, reinforcing the substrate determinantal role. CONCLUSION: Overall, our study uncovered some key active anaerobic lineages and their metabolic functions in this complex anaerobic ecosystem, offering a framework for understanding carbon transformations in anaerobic digestion. These findings advance the understanding of metabolic activities and trophic interactions between anaerobic guilds, providing foundational insights into carbon flux within both engineered and natural ecosystems. Video Abstract.


Assuntos
Carbono , Metagenômica , Metano , Metano/metabolismo , Carbono/metabolismo , Metagenômica/métodos , Reatores Biológicos/microbiologia , Metagenoma , Bactérias/genética , Bactérias/metabolismo , Bactérias/classificação , Filogenia , Anaerobiose , Transcriptoma , Genoma Bacteriano , Microbiota , Perfilação da Expressão Gênica
3.
Inorg Chem ; 63(26): 12377-12384, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38902911

RESUMO

Pathogenic bacteria have consistently posed a formidable challenge to human health, creating the critical need for effective antibacterial solutions. In response, enzyme-metal-organic framework (MOF) composites have emerged as a promising class of antibacterial agents. This study focuses on the development of an enzyme-MOF composite based on HZIF-8, incorporating the advantages of simple synthesis, ZIF-8 antibacterial properties, lysozyme hydrolysis, and high biological safety. Through a one-pot method, core-shell nanoparticles (HZIF-8) were synthesized. This structure enables efficient immobilization of lysozyme and lactoferrin within the HZIF-8, resulting in the formation of the lysozyme-lactoferrin@HZIF-8 (LYZ-LF@HZIF-8) composite. Upon exposure to light irradiation, HZIF-8 itself possessed antibacterial properties. Lysozyme initiated the degradation of bacterial peptidoglycan and lactoferrin synergistically enhanced the antibacterial effect of lysozyme. All of the above ultimately contributed to comprehensive antibacterial activity. Antibacterial assessments demonstrated the efficacy of the LYZ-LF@HZIF-8 composite, effectively eradicating Staphylococcus aureus at a cell density of 1.5 × 106 CFU/mL with a low dosage of 200 µg/mL and completely inactivating Escherichia coli at 400 µg/mL with the same cell density. The enzyme-MOF composite exhibited significant and durable antibacterial efficacy, with no apparent cytotoxicity in vitro, thereby unveiling expansive prospects for applications in the medical and food industries.


Assuntos
Antibacterianos , Escherichia coli , Lactoferrina , Estruturas Metalorgânicas , Testes de Sensibilidade Microbiana , Muramidase , Staphylococcus aureus , Zeolitas , Muramidase/farmacologia , Muramidase/química , Muramidase/metabolismo , Lactoferrina/química , Lactoferrina/farmacologia , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Estruturas Metalorgânicas/síntese química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Zeolitas/química , Zeolitas/farmacologia , Imidazóis/química , Imidazóis/farmacologia , Imidazóis/síntese química , Porosidade , Propriedades de Superfície , Tamanho da Partícula , Enzimas Imobilizadas/química , Enzimas Imobilizadas/farmacologia
4.
Pharmacol Res ; 206: 107280, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38914382

RESUMO

Digestive tract cancers are among the most common malignancies worldwide and have high incidence and mortality rates. Thus, the discovery of more effective diagnostic and therapeutic targets is urgently required. The development of technologies to accurately detect RNA modification has led to the identification of numerous RNA chemical modifications in humans (epitranscriptomics) that are involved in the occurrence and development of digestive tract cancers. RNA modifications can cooperatively regulate gene expression to facilitate normal physiological functions of the digestive system. However, the dysfunction of relevant RNA-modifying enzymes ("writers," "erasers," and "readers") can lead to the development of digestive tract cancers. Consequently, targeting dysregulated enzyme activity could represent a potent therapeutic strategy for the treatment of digestive tract cancers. In this review, we summarize the most widely studied roles and mechanisms of RNA modifications (m6A, m1A, m5C, m7G, A-to-I editing, pseudouridine [Ψ]) in relation to digestive tract cancers, highlight the crosstalk between RNA modifications, and discuss their roles in the interactions between the digestive system and microbiota during carcinogenesis. The clinical significance of novel therapeutic methods based on RNA-modifying enzymes is also discussed. This review will help guide future research into digestive tract cancers that are resistant to current therapeutics.

5.
Sensors (Basel) ; 24(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38894327

RESUMO

Advancements in machining technology demand higher speeds and precision, necessitating improved control systems in equipment like CNC machine tools. Due to lead errors, structural vibrations, and thermal deformation, commercial CNC controllers commonly use rotary encoders in the motor side to close the position loop, aiming to prevent insufficient stability and premature wear and damage of components. This paper introduces a multivariable iterative learning control (MILC) method tailored for flexible feed drive systems, focusing on enhancing dynamic positioning accuracy. The MILC employs error data from both the motor and table sides, enhancing precision by injecting compensation commands into both the reference trajectory and control command through a norm-optimization process. This method effectively mitigates conflicts between feedback control (FBC) and traditional iterative learning control (ILC) in flexible structures, achieving smaller tracking errors in the table side. The performance and efficacy of the MILC system are experimentally validated on an industrial biaxial CNC machine tool, demonstrating its potential for precision control in modern machining equipment.

6.
Chem Asian J ; : e202400533, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38863063

RESUMO

Organic fluorescent materials with red/near-infrared (NIR) emission are highly promising for use in biotechnology due to their exceptional advantages. However, traditional red/NIR fluorophores often exhibit weak emission at high concentrations or in an aggregated state due to the aggregate-caused quenching effect, which severely limits their applicability in biological imaging. To address this challenge, we developed a series of cyanostyrene derivatives with aggregation-induced emission characteristics, including 2,3-Bis-(4-styryl-phenyl)-but-2-enedinitrile (DPB), 2,3-Bis-{4-[2-(4-methoxy- phenyl)-vinyl]-phenyl}-but-2-enedinitrile (DOB), 2,3-Bis-{4-[2-(4-diphenylamino- phenyl)-vinyl]-phenyl}-but-2-enedinitrile (DTB), and 2,3-Bis-[4-(2-{4-[phenyl- (4-triphenylvinyl-phenyl)-amino]-phenyl}-vinyl)- phenyl]-but-2-enedinitrile (DTTB). Notably, these compounds exhibited intense solid state fluorescence owing to AIE effect, especially DTTB shows NIR emission with high solid state quantum efficiency (712 nm, ΦF=14.2%). Then we prepared DTTB@PS-PEG NPs nanoparticles by encapsulating DTTB with the amphiphilic polymer polystyrene-polyethylene glycol (PS-PEG). Importantly, DTTB@PS-PEG NPs exhibited highly efficient NIR luminescence (ΦF=28.7%) and a large two-photon absorption cross-section (1900 GM) under 800 nm laser excitation. The bright two-photon fluorescence of DTTB@PS-PEG indicated that it can be a highly promising candidate for two-photon fluorescence probe. Therefore, this work provides valuable insights for the design of highly efficient and NIR-emitting two-photon fluorescent probes.

8.
Appl Microbiol Biotechnol ; 108(1): 389, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904674

RESUMO

Direct ammonia oxidation (Dirammox) might be of great significance to advance the innovation of biological nitrogen removal process in wastewater treatment systems. However, it remains unknown whether Dirammox bacteria can be selectively enriched in activated sludge. In this study, a lab-scale bioreactor was established and operated for 2 months to treat synthetic wastewater with hydroxylamine as a selection pressure. Three Dirammox strains (Alcaligenes aquatilis SDU_AA1, Alcaligenes aquatilis SDU_AA2, and Alcaligenes sp. SDU_A2) were isolated from the activated sludge, and their capability to perform Dirammox process was confirmed. Although these three Dirammox bacteria were undetectable in the seed sludge (0%), their relative abundances rapidly increased after a month of operation, reaching 12.65%, 0.69%, and 0.69% for SDU_A2, SDU_AA1, and SDU_AA2, respectively. Among them, the most dominant Dirammox (SDU_A2) exhibited higher nitrogen removal rate (32.35%) than the other two strains (13.57% of SDU_AA1 and 14.52% of SDU_AA2). Comparative genomic analysis demonstrated that the most dominant Dirammox bacterium (SDU_A2) possesses fewer complete metabolic modules compared to the other two less abundant Alcaligenes strains. Our findings expanded the understanding of the application of Dirammox bacteria as key functional microorganisms in a novel biological nitrogen and carbon removal process if they could be well stabilized. KEY POINTS: • Dirammox-dominated microbial community was enriched in activated sludge bioreactor. • The addition of hydroxylamine played a role in Dirammox enrichment. • Three Dirammox bacterial strains, including one novel species, were isolated.


Assuntos
Alcaligenes , Reatores Biológicos , Nitrogênio , Oxirredução , Águas Residuárias , Águas Residuárias/microbiologia , Águas Residuárias/química , Reatores Biológicos/microbiologia , Nitrogênio/metabolismo , Alcaligenes/metabolismo , Alcaligenes/isolamento & purificação , Alcaligenes/genética , Esgotos/microbiologia , Amônia/metabolismo , Purificação da Água/métodos , Hidroxilamina/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Bactérias/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Microbiota
9.
Mol Med ; 30(1): 81, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862942

RESUMO

BACKGROUND: Studies have highlighted a possible crosstalk between the pathogeneses of COVID-19 and systemic lupus erythematosus (SLE); however, the interactive mechanisms remain unclear. We aimed to elucidate the impact of COVID-19 on SLE using clinical information and the underlying mechanisms of both diseases. METHODS: RNA-seq datasets were used to identify shared hub gene signatures between COVID-19 and SLE, while genome-wide association study datasets were used to delineate the interaction mechanisms of the key signaling pathways. Finally, single-cell RNA-seq datasets were used to determine the primary target cells expressing the shared hub genes and key signaling pathways. RESULTS: COVID-19 may affect patients with SLE through hematologic involvement and exacerbated inflammatory responses. We identified 14 shared hub genes between COVID-19 and SLE that were significantly associated with interferon (IFN)-I/II. We also screened and obtained four core transcription factors related to these hub genes, confirming the regulatory role of the IFN-I/II-mediated Janus kinase/signal transducers and activators of transcription (JAK-STAT) signaling pathway on these hub genes. Further, SLE and COVID-19 can interact via IFN-I/II and IFN-I/II receptors, promoting the levels of monokines, including interleukin (IL)-6/10, tumor necrosis factor-α, and IFN-γ, and elevating the incidence rate and risk of cytokine release syndrome. Therefore, in SLE and COVID-19, both hub genes and core TFs are enriched within monocytes/macrophages. CONCLUSIONS: The interaction between SLE and COVID-19 promotes the activation of the IFN-I/II-triggered JAK-STAT signaling pathway in monocytes/macrophages. These findings provide a new direction and rationale for diagnosing and treating patients with SLE-COVID-19 comorbidity.


Assuntos
COVID-19 , Estudo de Associação Genômica Ampla , Lúpus Eritematoso Sistêmico , SARS-CoV-2 , Transdução de Sinais , Humanos , COVID-19/genética , Lúpus Eritematoso Sistêmico/genética , SARS-CoV-2/fisiologia , Feminino , Janus Quinases/metabolismo , Fatores de Transcrição STAT/metabolismo , Fatores de Transcrição STAT/genética , Masculino , Transcriptoma , Perfilação da Expressão Gênica , Multiômica
10.
Nat Commun ; 15(1): 5080, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871724

RESUMO

The reconstruction of Cu catalysts during electrochemical reduction of CO2 is a widely known but poorly understood phenomenon. Herein, we examine the structural evolution of Cu nanocubes under CO2 reduction reaction and its relevant reaction conditions using identical location transmission electron microscopy, cyclic voltammetry, in situ X-ray absorption fine structure spectroscopy and ab initio molecular dynamics simulation. Our results suggest that Cu catalysts reconstruct via a hitherto unexplored yet critical pathway - alkali cation-induced cathodic corrosion, when the electrode potential is more negative than an onset value (e.g., -0.4 VRHE when using 0.1 M KHCO3). Having alkali cations in the electrolyte is critical for such a process. Consequently, Cu catalysts will inevitably undergo surface reconstructions during a typical process of CO2 reduction reaction, resulting in dynamic catalyst morphologies. While having these reconstructions does not necessarily preclude stable electrocatalytic reactions, they will indeed prohibit long-term selectivity and activity enhancement by controlling the morphology of Cu pre-catalysts. Alternatively, by operating Cu catalysts at less negative potentials in the CO electrochemical reduction, we show that Cu nanocubes can provide a much more stable selectivity advantage over spherical Cu nanoparticles.

11.
Zhen Ci Yan Jiu ; 49(6): 594-603, 2024 Jun 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38897803

RESUMO

OBJECTIVES: To observe the effect of electroacupuncture (EA) on behavior and hippocampal protein phosphorylation in rats with chronic fatigue syndrome (CFS), so as to explore its mechanisms underlying improvement of CFS. METHODS: Male SD rats were randomly divided into control, model and EA groups (n=12 rats in each group). The CFS model was established by chronic multifactor combined with stress stimulation (treadmill training + restraint stress + sleep disturbance + crowded environment). For rats of the EA group, EA (1 mA, frequency of 10 Hz) was applied to "Shenting" (GV24) (with an acupuncture needle penetrated from GV24 to "Baihui" ï¼»GV20ï¼½) and "Dazhui" (GV14) for 15 min, once daily for 28 days. After treatment, the body weight, food intake and water intake of rats in each group were observed. The fatigue degree of rats was evaluated by Semi-quantitative score observation table of the general condition of experimental rats.The open field test (OFT) was used to assess the rats'anxiety severity by detecting the total number of grid-crossing and the times of the central area entered in 5 min, and Morris water maze test was employed to assess the rats' learning-memory ability by detecting the escape latency in 1 min, and the times of the original platform quadrant crossing in 1 min. The hippocampaus was taken for phosphorylated Label-free quantitative proteomics analysis by using Maxquant technology based on full scan mode to calculate the integral of each peptide signal of liquid chromatography-mass spectrometry(LC-MS). The differentially-expressed proteins (>1.5 folds for up-regulation or <0.67 folds for down-regulation) were evaluated by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. RESULTS: Compared with the control group, the body weight, food intake, and the times of original-platform quadrant crossing of spatial exploring of Morris water maze test were significantly decreased (P<0.01, P<0.05) , and the score of general conditions, times of grid-crossing and center area-entering of OFT, and the escape latency of navigation task were apparently increased (P<0.01) in rats of the model group. After EA intervention, the decreased original-platform quadrant crossing, and the increased score of general conditions, times of grid-crossing and the escape latency of navigation task were all reversed (P<0.01, P<0.05). Outcomes of proteomics analysis indicated that compared with the model group, there were 297 differentially expressed peptide (48 up-regulated and 249 down-regulated) segments in the control group, and there were 245 differentially expressed peptide (185 up-regulated and 60 down-regulated) segments in the EA group, in which, 25 overlapping peptide segments were reversed after EA treatment, corresponding to 24 proteins, mainly involving cytoskeletal structure. GO function annotation analysis showed that the top three differentially expressed phosphorylated proteins involved in the effect of EA intervention were the actin filament polymerization, protein depolymerization and cytoskeletal tissue in the biological process, the actin binding, structural molecular activity and cytoskeletal protein binding in the molecular function, and the cytoskeleton, dendrites and dendritic trees in the cellular component, respectively. The KEGG pathway annotation analysis for differentially expressed phosphorylated proteins showed that theinsulin secretion, axon guidance, phosphatidylinositol signaling system and lysine biosynthesis, etc. were involved in the effect of EA intervention. CONCLUSIONS: EA of GV24-GV20 and GV14 can improve the general state, anxiety and learning-memory ability of CFS model rats, which may be related to its functions in regulating the hippocampal protein phosphorylation level, and repairing the structure and function of synapses in hippocampus.


Assuntos
Eletroacupuntura , Síndrome de Fadiga Crônica , Hipocampo , Ratos Sprague-Dawley , Animais , Masculino , Ratos , Hipocampo/metabolismo , Síndrome de Fadiga Crônica/terapia , Síndrome de Fadiga Crônica/metabolismo , Fosforilação , Humanos , Pontos de Acupuntura , Modelos Animais de Doenças
12.
Dalton Trans ; 53(23): 9675-9679, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38814118

RESUMO

Two new histidine-templated metal phosphate-oxalates (MPOs) were prepared under solvent-free conditions. Single-crystal X-ray diffraction analysis reveals that they have layered and chainlike structures, respectively. Under ultraviolet light irradiation, the two MPOs exhibit blue luminescence originating from histidine templates. Their proton-conducting properties were also investigated under different conditions.

13.
Brain Struct Funct ; 229(6): 1433-1445, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38801538

RESUMO

Previous studies on structural covariance network (SCN) suggested that patients with insomnia disorder (ID) show abnormal structural connectivity, primarily affecting the somatomotor network (SMN) and default mode network (DMN). However, evaluating a single structural index in SCN can only reveal direct covariance relationship between two brain regions, failing to uncover synergistic changes in multiple structural features. To cover this research gap, the present study utilized novel morphometric similarity networks (MSN) to examine the morphometric similarity between cortical areas in terms of multiple sMRI parameters measured at each area. With seven T1-weighted imaging morphometric features from the Desikan-Killiany atlas, individual MSN was constructed for patients with ID (N = 87) and healthy control groups (HCs, N = 84). Two-sample t-test revealed differences in MSN between patients with ID and HCs. Correlation analyses examined associations between MSNs and sleep quality, insomnia symptom severity, and depressive symptoms severity in patients with ID. The right paracentral lobule (PCL) exhibited decreased morphometric similarity in patients with ID compared to HCs, mainly manifested by its de-differentiation (meaning loss of distinctiveness) with the SMN, DMN, and ventral attention network (VAN), as well as its decoupling with the visual network (VN). Greater PCL-based de-differentiation correlated with less severe insomnia and fewer depressive symptoms in the patients group. Additionally, patients with less depressive symptoms showed greater PCL de-differentiation from the SMN. As an important pilot step in revealing the underlying morphometric similarity alterations in insomnia disorder, the present study identified the right PCL as a hub region that is de-differentiated with other high-order networks. Our study also revealed that MSN has an important potential to capture clinical significance related to insomnia disorder.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Distúrbios do Início e da Manutenção do Sono , Humanos , Distúrbios do Início e da Manutenção do Sono/patologia , Distúrbios do Início e da Manutenção do Sono/diagnóstico por imagem , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Encéfalo/patologia , Encéfalo/diagnóstico por imagem , Rede Nervosa/patologia , Rede Nervosa/diagnóstico por imagem , Vias Neurais/patologia , Vias Neurais/diagnóstico por imagem , Mapeamento Encefálico , Adulto Jovem
14.
Molecules ; 29(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38731456

RESUMO

The construction of high-performance n-type semiconductors is crucial for the advancement of organic electronics. As an attractive n-type semiconductor, molecular systems based on perylene diimide derivatives (PDIs) have been extensively investigated over recent years. Owing to the fascinating aggregated structure and high performance, S-heterocyclic annulated PDIs (SPDIs) are receiving increasing attention. However, the relationship between the structure and the electrical properties of SPDIs has not been deeply revealed, restricting the progress of PDI-based organic electronics. Here, we developed two novel SPDIs with linear and dendronized substituents in the imide position, named linear SPDI and dendronized SPDI, respectively. A series of structural and property characterizations indicated that linear SPDI formed a long-range-ordered crystalline structure based on helical supramolecular columns, while dendronized SPDI, with longer alkyl side chains, formed a 3D-ordered crystalline structure at a low temperature, which transformed into a hexagonal columnar liquid crystal structure at a high temperature. Moreover, no significant charge carrier transport signal was examined for linear SPDI, while dendronized SPDI had a charge carrier mobility of 3.5 × 10-3 cm2 V-1 s-1 and 2.1 × 10-3 cm2 V-1 s-1 in the crystalline and liquid crystalline state, respectively. These findings highlight the importance of the structure-function relationship in PDIs, and also offer useful roadmaps for the design of high-performance organic electronics for down-to-earth applications.

15.
Org Lett ; 26(21): 4548-4553, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38757610

RESUMO

gem-Difluoroalkenes and monofluorinated cycloalkenes have emerged as basic structural units in a variety of bioactive molecules and natural products. Thus, developing straightforward and efficient methods for synthesizing fluorinated alkene compounds is of considerable significance. Herein, we disclose a visible-light-induced defluorination of 2-trifluoromethyl-1-alkene via a 1,5-HAT process using N-alkoxyphtalimides as both radical precursor and potential nucleophile. The mild and stepwise reaction leads to a variety of structurally diverse gem-difluoroalkenes and monofluorinated cyclooctenes with high efficiency, respectively.

16.
Artigo em Inglês | MEDLINE | ID: mdl-38743547

RESUMO

The superior performance of modern computer vision backbones (e.g., vision Transformers learned on ImageNet-1K/22K) usually comes with a costly training procedure. This study contributes to this issue by generalizing the idea of curriculum learning beyond its original formulation, i.e., training models using easier-to-harder data. Specifically, we reformulate the training curriculum as a soft-selection function, which uncovers progressively more difficult patterns within each example during training, instead of performing easier-to-harder sample selection. Our work is inspired by an intriguing observation on the learning dynamics of visual backbones: during the earlier stages of training, the model predominantly learns to recognize some 'easier-to-learn' discriminative patterns in the data. These patterns, when observed through frequency and spatial domains, incorporate lower-frequency components, and the natural image contents without distortion or data augmentation. Motivated by these findings, we propose a curriculum where the model always leverages all the training data at every learning stage, yet the exposure to the 'easier-to-learn' patterns of each example is initiated first, with harder patterns gradually introduced as training progresses. To implement this idea in a computationally efficient way, we introduce a cropping operation in the Fourier spectrum of the inputs, enabling the model to learn from only the lower-frequency components. Then we show that exposing the contents of natural images can be readily achieved by modulating the intensity of data augmentation. Finally, we integrate these two aspects and design curriculum learning schedules by proposing tailored searching algorithms. Moreover, we present useful techniques for deploying our approach efficiently in challenging practical scenarios, such as large-scale parallel training, and limited input/output or data pre-processing speed. The resulting method, EfficientTrain++, is simple, general, yet surprisingly effective. As an off-the-shelf approach, it reduces the training time of various popular models (e.g., ResNet, ConvNeXt, DeiT, PVT, Swin, CSWin, and CAFormer) by [Formula: see text] on ImageNet-1K/22K without sacrificing accuracy. It also demonstrates efficacy in self-supervised learning (e.g., MAE). Code is available at: https://github.com/LeapLabTHU/EfficientTrain.

17.
Gut Microbes ; 16(1): 2347725, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38722028

RESUMO

The gut commensal bacteria Christensenellaceae species are negatively associated with many metabolic diseases, and have been seen as promising next-generation probiotics. However, the cultured Christensenellaceae strain resources were limited, and their beneficial mechanisms for improving metabolic diseases have yet to be explored. In this study, we developed a method that enabled the enrichment and cultivation of Christensenellaceae strains from fecal samples. Using this method, a collection of Christensenellaceae Gut Microbial Biobank (ChrisGMB) was established, composed of 87 strains and genomes that represent 14 species of 8 genera. Seven species were first described and the cultured Christensenellaceae resources have been significantly expanded at species and strain levels. Christensenella strains exerted different abilities in utilization of various complex polysaccharides and other carbon sources, exhibited host-adaptation capabilities such as acid tolerance and bile tolerance, produced a wide range of volatile probiotic metabolites and secondary bile acids. Cohort analyses demonstrated that Christensenellaceae and Christensenella were prevalent in various cohorts and the abundances were significantly reduced in T2D and OB cohorts. At species level, Christensenellaceae showed different changes among healthy and disease cohorts. C. faecalis, F. tenuis, L. tenuis, and Guo. tenuis significantly reduced in all the metabolic disease cohorts. The relative abundances of C. minuta, C. hongkongensis and C. massiliensis showed no significant change in NAFLD and ACVD. and C. tenuis and C. acetigenes showed no significant change in ACVD, and Q. tenuis and Geh. tenuis showed no significant change in NAFLD, when compared with the HC cohort. So far as we know, this is the largest collection of cultured resource and first exploration of Christensenellaceae prevalences and abundances at species level.


Assuntos
Fezes , Microbioma Gastrointestinal , Humanos , Fezes/microbiologia , Clostridiales/genética , Clostridiales/metabolismo , Clostridiales/isolamento & purificação , Clostridiales/classificação , Probióticos/metabolismo , Metabolômica , Genômica , Masculino , Filogenia , Feminino , Genoma Bacteriano
18.
Langmuir ; 40(20): 10486-10491, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38728233

RESUMO

In view of the excellent prospects of gene therapy and the potential safety and immunogenicity issues challenged by viral vectors, it is of great significance to develop a nonviral vector with low toxicity and low cost. In this work, we report a chitosan nanoparticle (CSNP) to be used as a gene vector prepared through a facile solvent-exchange strategy. Chitosan is first dissolved in ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM Ac), and then, the solvent is exchanged with water/phosphate-buffered saline (PBS) to remove ionic liquid, forming a final CSNP dispersion after ultrasonication. The prepared CSNP shows a positive surface charge and can condense green fluorescent protein-encoding plasmid (pGFP) at weight ratios (CSNP/pGFP) of 5/1 or higher. Dynamic light scattering size and ζ-potential characterization and gel retardation results confirm the formation of CSNP/pGFP complexes. Compared with plain pGFP, efficient cellular internalization and significantly enhanced green fluorescent protein (GFP) expression are observed by using CSNP as a plasmid vector. Benefitting from the intrinsic biocompatibility, low cost, low immunogenicity, and abundant sources of chitosan, as well as the facile preparation and the efficient gene transfection capacity of CSNP, it is believed that this CSNP could be used as a nonviral gene vector with great clinical translational potentials.


Assuntos
Quitosana , Proteínas de Fluorescência Verde , Nanopartículas , Plasmídeos , Solventes , Quitosana/química , Nanopartículas/química , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/genética , Humanos , Solventes/química , Plasmídeos/química , Plasmídeos/genética , Técnicas de Transferência de Genes , Transfecção/métodos , Tamanho da Partícula , Células HeLa
19.
Mater Today Bio ; 26: 101088, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38779556

RESUMO

Osteogenic-osteoclast coupling processes play a crucial role in bone regeneration. Recently, strategies that focus on multi-functionalized implant surfaces to enhance the healing of bone defects through the synergistic regulation of osteogenesis and osteoclastogenesis is still a challenging task in the field of bone tissue engineering. The aim of this study was to create a dual-drug release-based core-shell nanofibers with the intent of achieving a time-controlled release to facilitate bone regeneration. We fabricated core-shell P/PCL nanofibers using coaxial electrospinning, where alendronate (ALN) was incorporated into the core layer and hydroxyapatite (HA) into shell. The surface of the nanofiber construct was further modified with mussel-derived polydopamine (PDA) to induce hydrophilicity and enhance cell interactions. Surface characterizations confirmed the successful synthesis of PDA@PHA/PCL-ALN nanofibers endowed with excellent mechanical strength (20.02 ± 0.13 MPa) and hydrophilicity (22.56°), as well as the sustained sequential release of ALN and Ca ions. In vitro experiments demonstrated that PDA-functionalized core-shell PHA/PCL-ALN scaffolds possessed excellent cytocompatibility, enhanced cell adhesion and proliferation, alkaline phosphatase activity and osteogenesis-related genes. In addition to osteogenesis, the engineered scaffolds also significantly reduced osteoclastogenesis, such as tartrate-resistant acid phosphatase activity and osteoclastogenesis-related gene expression. After 12-week of implantation, it was observed that PDA@PHA/PCL-ALN nanofiber scaffolds, in a rat cranial defect model, significantly promoted bone repair and regeneration. Microcomputed tomography, histological examination, and immunohistochemical analysis collectively demonstrated that the PDA-functionalized core-shell PHA/PCL-ALN scaffolds exhibited exceptional osteogenesis-inducing and osteoclastogenesis-inhibiting effects. Finally, it may be concluded from our results that the bio-inspired surface-functionalized multifunctional, biomimetic and controlled release core-shell nanofiber provides a promising strategy to facilitate bone healing.

20.
Hum Cell ; 37(4): 1039-1055, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38753279

RESUMO

The link between ferroptosis, a form of cell death mediated by iron and acute kidney injury (AKI) is recently gaining widespread attention. However, the mechanism of the crosstalk between cells in the pathogenesis and progression of acute kidney injury remains unexplored. In our research, we performed a non-negative matrix decomposition (NMF) algorithm on acute kidney injury single-cell RNA sequencing data based specifically focusing in ferroptosis-associated genes. Through a combination with pseudo-time analysis, cell-cell interaction analysis and SCENIC analysis, we discovered that proximal tubular cells, macrophages, and fibroblasts all showed associations with ferroptosis in different pathways and at various time. This involvement influenced cellular functions, enhancing cellular communication and activating multiple transcription factors. In addition, analyzing bulk expression profiles and marker genes of newly defined ferroptosis subtypes of cells, we have identified crucial cell subtypes, including Egr1 + PTC-C1, Jun + PTC-C3, Cxcl2 + Mac-C1 and Egr1 + Fib-C1. All these subtypes which were found in AKI mice kidneys and played significantly distinct roles from those of normal mice. Moreover, we verified the differential expression of Egr1, Jun, and Cxcl2 in the IRI mouse model and acute kidney injury human samples. Finally, our research presented a novel analysis of the crosstalk of proximal tubular cells, macrophages and fibroblasts in acute kidney injury targeting ferroptosis, therefore, contributing to better understanding the acute kidney injury pathogenesis, self-repairment and acute kidney injury-chronic kidney disease (AKI-CKD) progression.


Assuntos
Injúria Renal Aguda , Ferroptose , Fibroblastos , Túbulos Renais Proximais , Macrófagos , Análise de Célula Única , Injúria Renal Aguda/patologia , Injúria Renal Aguda/metabolismo , Ferroptose/genética , Ferroptose/fisiologia , Macrófagos/metabolismo , Macrófagos/fisiologia , Humanos , Animais , Fibroblastos/metabolismo , Fibroblastos/patologia , Análise de Célula Única/métodos , Túbulos Renais Proximais/patologia , Túbulos Renais Proximais/citologia , Camundongos , Comunicação Celular , Modelos Animais de Doenças
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...