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1.
Medicine (Baltimore) ; 103(26): e38700, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941382

RESUMO

This study aims to critically reassess existing systematic reviews (SR) on Traditional Chinese Exercises (TCE) for treating Chronic Obstructive Pulmonary Disease (COPD). The primary objectives include synthesizing available evidence, evaluating the methodological quality of reviews and overall evidence, and providing comprehensive insights into the effectiveness of different TCE types in managing COPD. Sinomed, CNKI, VIP, Wanfang, PubMed, Cochrane Library, and Web of Science were searched from inception to April 2023 for SR literature on the treatment of COPD with TCE. The extracted data from the included SRs encompassed various aspects such as general information, study population, intervention measures, meta-analysis results, and conclusions. The methodological quality of the included SRs was assessed using the AMSTAR II tool. Additionally, the GRADE tool was used to determine the evidence level of outcome indicators. This study included 17 SRs and 4 types of TCE. The CCA was 0.041, indicating a slight overlap between the primary studies. Notably, one study was rated as low quality on the AMSTAR II scale, while the rest were classified as critically low quality. The results from the GRADE evaluation revealed 26 pieces of very low-quality evidence, 55 pieces of low-quality evidence, and 17 pieces of moderate-quality evidence. The moderate-quality evidence suggests that Liuzijue effectively improves TCM syndrome scores in patients with COPD. Additionally, low-quality evidence suggests that Liuzijue improves patients' lung function (FEV1, FVC) and quality of life (CAT, MRC/mMRC). Similarly, low-quality evidence suggests that Baduanjin can improve patients' lung function (FEV1%, FVC) and quality of life (SGRQ). Low-quality evidence also suggests that Health Qigong can significantly improve patients' exercise endurance (6MWD). No SR reported TCE-related adverse reactions. TCE interventions are effective and safe in the treatment of COPD. Different types of TCE have varying effects on outcomes in COPD patients. However, these findings are limited by the generally low methodological and evidence quality of the included SRs. Therefore, it is strongly recommended to improve study designs to obtain higher-quality clinical evidence and to strictly follow SR protocols.


Assuntos
Medicina Tradicional Chinesa , Doença Pulmonar Obstrutiva Crônica , Revisões Sistemáticas como Assunto , Doença Pulmonar Obstrutiva Crônica/terapia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/reabilitação , Humanos , Medicina Tradicional Chinesa/métodos , Terapia por Exercício/métodos , Qualidade de Vida , Qigong/métodos , População do Leste Asiático
2.
Food Res Int ; 188: 114525, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823888

RESUMO

As a kind of green tea with unique multiple baking processes, the flavor code of Lu'an Guapian (LAGP) has recently been revealed. To improve and stabilize the quality of LAGP, further insight into the dynamic changes in odorants during the whole processing is required. In this study, 50 odorants were identified in processing tea leaves, 14 of which were selected for absolute quantification to profile the effect of processes. The results showed that spreading is crucial for key aroma generation and accumulation, while these odorants undergo significant changes at the deep baking stage. By adjusting the conditions of the spreading and deep baking, it was found that low-temperature (4 °C) spreading for 6 h and low-temperature with long-time baking (final leaf temperature: 102 °C, 45 min) could improve the overall aroma quality. These results provide a new direction for enhancing the quality of LAGP green tea.


Assuntos
Odorantes , Chá , Compostos Orgânicos Voláteis , Odorantes/análise , Chá/química , Compostos Orgânicos Voláteis/análise , Folhas de Planta/química , Manipulação de Alimentos/métodos , Culinária/métodos , Camellia sinensis/química , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta
3.
Cells ; 13(11)2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38891022

RESUMO

Pulmonary surfactants play a crucial role in managing lung lipid metabolism, and dysregulation of this process is evident in various lung diseases. Alternations in lipid metabolism lead to pulmonary surfactant damage, resulting in hyperlipidemia in response to lung injury. Lung macrophages are responsible for recycling damaged lipid droplets to maintain lipid homeostasis. The inflammatory response triggered by external stimuli such as cigarette smoke, bleomycin, and bacteria can interfere with this process, resulting in the formation of lipid-laden macrophages (LLMs), also known as foamy macrophages. Recent studies have highlighted the potential significance of LLM formation in a range of pulmonary diseases. Furthermore, growing evidence suggests that LLMs are present in patients suffering from various pulmonary conditions. In this review, we summarize the essential metabolic and signaling pathways driving the LLM formation in chronic obstructive pulmonary disease, pulmonary fibrosis, tuberculosis, and acute lung injury.


Assuntos
Metabolismo dos Lipídeos , Pneumopatias , Humanos , Pneumopatias/metabolismo , Pneumopatias/patologia , Animais , Macrófagos/metabolismo , Macrófagos Alveolares/metabolismo , Transdução de Sinais
4.
Micron ; 185: 103679, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38924906

RESUMO

A heterostructured crystalline bilayer specimen is known to produce moiré fringes (MFs) in the conventional transmission electron microscopy (TEM). However, the understanding of how these patterns form in scanning transmission electron microscopy (STEM) remains limited. Here, we extended the double-scattering model to establish the imaging theory of MFs in STEM for a bilayer sample and applied this theory to successfully explain both experimental and simulated STEM images of a perovskite PbZrO3/SrTiO3 system. Our findings demonstrated that the wave vectors of electrons exiting from Layer-1 and their relative positions with the atomic columns of Layer-2 should be taken into account. The atomic column misalignment leads to a faster reduction in the intensity of the secondary scattering beam compared to the single scattering beam as the scattering angle increases. Consequently, the intensity distribution of MFs in the bright field (BF)-STEM can be still described as the product of two single atomic images. However, in high angle annular dark field (HAADF)-STEM, it is approximately described as the superposition of the two images. Our work not only fills a knowledge gap of MFs in incoherent imaging, but also emphasizes the importance of the coherent scattering restricted by the real space when analyzing the HAADF-STEM imaging.

5.
Adv Mater ; : e2401694, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38721895

RESUMO

Hydrazine oxidation-assisted water splitting is a critical technology to tackle the high energy consumption in large-scale H2 production. Ru-based electrocatalysts hold promise for synergetic hydrogen reduction (HER) and hydrazine oxidation (HzOR) catalysis but are hindered by excessive superficial adsorption of reactant intermediate. Herein, this work designs Ru cluster anchoring on NiFe-LDH (denoted as Ruc/NiFe-LDH), which effectively enhances the intermediate adsorption capacity of Ru by constructing Ru─O─Ni/Fe bridges. Notably, it achieves an industrial current density of 1 A cm-2 at an unprecedentedly low voltage of 0.43 V, saving 3.94 kWh m-3 H2 in energy, and exhibits remarkable stability over 120 h at a high current density of 5 A cm-2. Advanced characterizations and theoretical calculation reveal that the presence of Ru─O─Ni/Fe bridges widens the d-band width (Wd) of the Ru cluster, leading to a lower d-band center and higher electron occupation on antibonding orbitals, thereby facilitating moderate adsorption energy and enhanced catalytic activity of Ru.

6.
Nat Commun ; 15(1): 3949, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38729934

RESUMO

Topological domain structures have drawn great attention as they have potential applications in future electronic devices. As an important concept linking the quantum and classical magnetism, a magnetic Bloch point, predicted in 1960s but not observed directly so far, is a singular point around which magnetization vectors orient to nearly all directions. Here we show polar Bloch points in tensile-strained ultrathin ferroelectric PbTiO3 films, which are alternatively visualized by phase-field simulations and aberration-corrected scanning transmission electron microscopic imaging. The phase-field simulations indicate local steady-state negative capacitance around the Bloch points. The observation of polar Bloch points and their emergent properties consequently implies novel applications in future integrated circuits and low power electronic devices.

8.
Food Chem ; 452: 139603, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38754166

RESUMO

Food fraud is common in the tuna industry because of the economic benefits involved. Ensuring the authenticity of tuna species is crucial for protecting both consumers and tuna stocks. In this study, GC-Q-TOF and UPLC-Q/Orbitrap mass spectrometry-based metabolomics were used to investigate the metabolite profiles of three commercial tuna species (skipjack tuna, bigeye tuna and yellowfin tuna). A total of 22 and 77 metabolites were identified with high confidence using GC-Q-TOF and UPLC-Q/Orbitrap mass spectrometry, respectively. Further screening via chemometrics revealed that 38 metabolites could potentially serve as potential biomarkers. Hierarchical cluster analysis showed that the screened metabolite biomarkers successfully distinguished the three tested tuna species. Furthermore, a total of 27 metabolic pathways were identified through enrichment analysis based on the Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathways.


Assuntos
Metabolômica , Atum , Atum/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Alimentos Marinhos/análise , Quimiometria , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas , Biomarcadores/metabolismo , Biomarcadores/análise
9.
Research (Wash D C) ; 7: 0358, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38779487

RESUMO

Helicobacter pylori colonizes over 50% of people worldwide. Biofilm formation through penetrating gastric mucus and resistance acquired by H. pylori markedly reduces the efficacy of traditional antibiotics. The present triple therapy and bismuth-based quadruple therapy inevitably causes intestinal flora disturbance and fails to address the excessive H. pylori-triggered inflammatory response. Herein, a mucus-permeable therapeutic platform (Cu-MOF@NF) that consists of copper-bearing metal-organic framework (Cu-MOF) loaded with nitrogen-doped carbon dots and naturally active polysaccharide fucoidan is developed. The experimental results demonstrate that Cu-MOF@NF can penetrate the mucus layer and hinder H. pylori from adhering on gastric epithelial cells of the stomach. Notably, released Cu2+ can degrade the polysaccharides in the biofilm and interfere with the cyclic growing mode of "bacterioplankton ↔ biofilm", thereby preventing recurrent and persistent infection. Compared with traditional triple therapy, the Cu-MOF@NF not only possesses impressive antibacterial effect (even include multidrug-resistant strains), but also improves the inflammatory microenvironment without disrupting the balance of intestinal flora, providing a more efficient, safe, and antibiotic-free new approach to eradicating H. pylori.

10.
J Inflamm Res ; 17: 2531-2546, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38689798

RESUMO

Ferroptosis, a type of programmed cell death that relies on iron, is distinct in terms of its morphological, biochemical and genetic features. Unlike other forms of cell death, such as autophagy, apoptosis, necrosis, and pyroptosis, ferroptosis is primarily caused by lipid peroxidation. Cells that die due to iron can potentially trigger an immune response which intensifies inflammation and causes severe inflammatory reactions that eventually lead to multiple organ failure. In recent years, ferroptosis has been identified in an increasing number of medical fields, including neurological pathologies, chronic liver diseases and sepsis. Ferroptosis has the potential to cause an inflammatory tempest, with many of the catalysts and pathological indications of respiratory ailments being linked to inflammatory reactions. The growing investigation into ferroptosis in respiratory disorders has also garnered significant interest to better understand the mechanism of ferroptosis in these diseases. In this review, the recent progress in understanding the molecular control of ferroptosis and its mechanism in different respiratory disorders is examined. In addition, this review discusses current challenges and prospects for understanding the link between respiratory diseases and ferroptosis.

11.
Food Res Int ; 187: 114462, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38763689

RESUMO

The risk of tuna adulteration is high driven by economic benefits. The authenticity of tuna is required to protect both consumers and tuna stocks. Given this, the study is designed to identify species-specific peptides for distinguishing three commercial tropical tuna species. The peptides derived from trypsin digestion were separated and detected using ultrahigh-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) in data-dependent acquisition (DDA) mode. Venn analysis showed that there were differences in peptide composition among the three tested tuna species. The biological specificity screening through the National Center for Biotechnology Information's Basic Local Alignment Search Tool (NCBI BLAST) revealed that 93 peptides could serve as potential species-specific peptides. Finally, the detection specificity of species-specific peptides of raw meats and processed products was carried out by multiple reaction monitoring (MRM) mode based on a Q-Trap mass spectrometer. The results showed that three, one and two peptides of Katsuwonus pelamis, Thunnus obesus and Thunnus albacores, respectively could serve as species-specific peptides.


Assuntos
Peptídeos , Especificidade da Espécie , Atum , Animais , Peptídeos/análise , Espectrometria de Massas/métodos , Cromatografia Líquida de Alta Pressão/métodos , Alimentos Marinhos/análise , Contaminação de Alimentos/análise , Proteínas de Peixes/análise
12.
Int J Biol Macromol ; 267(Pt 2): 131577, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38615853

RESUMO

Chondroitin sulphates (CSs) are the most well-known glycosaminoglycans (GAGs) found in any living organism, from microorganisms to invertebrates and vertebrates (including humans), and provide several health benefits. The applications of CSs are numerous including tissue engineering, osteoarthritis treatment, antiviral, cosmetics, and skincare applications. The current commercial production of CSs mostly uses animal, bovine, porcine, and avian tissues as well as marine organisms, marine mammals, sharks, and other fish. The production process consists of tissue hydrolysis, protein removal, and purification using various methods. Mostly, these are chemical-dependent and are complex, multi-step processes. There is a developing trend for abandonment of harsh extraction chemicals and their substitution with different green-extraction technologies, however, these are still in their infancy. The quality of CSs is the first and foremost requirement for end-applications and is dependent on the extraction and purification methodologies used. The final products will show different bio-functional properties, depending on their origin and production methodology. This is a comprehensive review of the characteristics, properties, uses, sources, and extraction methods of CSs. This review emphasises the need for extraction and purification processes to be environmentally friendly and gentle, followed by product analysis and quality control to ensure the expected bioactivity of CSs.


Assuntos
Sulfatos de Condroitina , Animais , Sulfatos de Condroitina/química , Humanos , Cosméticos/química , Engenharia Tecidual
13.
World J Gastroenterol ; 30(14): 2038-2058, 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38681131

RESUMO

BACKGROUND: Acute pancreatitis (AP) encompasses a spectrum of pancreatic inflammatory conditions, ranging from mild inflammation to severe pancreatic necrosis and multisystem organ failure. Given the challenges associated with obtaining human pancreatic samples, research on AP predominantly relies on animal models. In this study, we aimed to elucidate the fundamental molecular mechanisms underlying AP using various AP models. AIM: To investigate the shared molecular changes underlying the development of AP across varying severity levels. METHODS: AP was induced in animal models through treatment with caerulein alone or in combination with lipopolysaccharide (LPS). Additionally, using Ptf1α to drive the specific expression of the hM3 promoter in pancreatic acinar cells transgenic C57BL/6J- hM3/Ptf1α(cre) mice were administered Clozapine N-oxide to induce AP. Subsequently, we conducted RNA sequencing of pancreatic tissues and validated the expression of significantly different genes using the Gene Expression Omnibus (GEO) database. RESULTS: Caerulein-induced AP showed severe inflammation and edema, which were exacerbated when combined with LPS and accompanied by partial pancreatic tissue necrosis. Compared with the control group, RNA sequencing analysis revealed 880 significantly differentially expressed genes in the caerulein model and 885 in the caerulein combined with the LPS model. Kyoto Encyclopedia of Genes and Genomes enrichment analysis and Gene Set Enrichment Analysis indicated substantial enrichment of the TLR and NOD-like receptor signaling pathway, TLR signaling pathway, and NF-κB signaling pathway, alongside elevated levels of apoptosis-related pathways, such as apoptosis, P53 pathway, and phagosome pathway. The significantly elevated genes in the TLR and NOD-like receptor signaling pathways, as well as in the apoptosis pathway, were validated through quantitative real-time PCR experiments in animal models. Validation from the GEO database revealed that only MYD88 concurred in both mouse pancreatic tissue and human AP peripheral blood, while TLR1, TLR7, RIPK3, and OAS2 genes exhibited marked elevation in human AP. The genes TUBA1A and GADD45A played significant roles in apoptosis within human AP. The transgenic mouse model hM3/Ptf1α(cre) successfully validated significant differential genes in the TLR and NOD-like receptor signaling pathways as well as the apoptosis pathway, indicating that these pathways represent shared pathological processes in AP across different models. CONCLUSION: The TLR and NOD receptor signaling pathways play crucial roles in the inflammatory progression of AP, notably the MYD88 gene. Apoptosis holds a central position in the necrotic processes of AP, with TUBA1A and GADD45A genes exhibiting prominence in human AP.


Assuntos
Ceruletídeo , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pâncreas , Pancreatite , Fatores de Transcrição , Animais , Ceruletídeo/toxicidade , Camundongos , Pancreatite/genética , Pancreatite/induzido quimicamente , Pancreatite/patologia , Pancreatite/metabolismo , Perfilação da Expressão Gênica/métodos , Pâncreas/patologia , Pâncreas/metabolismo , Humanos , Transcriptoma , Masculino , Transdução de Sinais , Células Acinares/metabolismo , Células Acinares/patologia
14.
Front Immunol ; 15: 1392099, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38686384

RESUMO

Background: Asparaginase (ASNase) is a crucial part of acute leukemia treatment, but immune responses to the agent can reduce its effectiveness and increase the risk of relapse. Currently, no reliable and validated biomarker predicts ASNase-induced hypersensitivity reactions during therapy. We aimed to identify predictive biomarkers and determine immune cells responsible for anaphylaxis using a murine model of ASNase hypersensitivity. Methods: Our preclinical study uses a murine model to investigate predictive biomarkers of ASNase anaphylaxis, including anti-ASNase antibody responses, immune complex (IC) levels, ASNase-specific binding to leukocytes or basophils, and basophil activation. Results: Our results indicate that mice immunized to ASNase exhibited dynamic IgM, IgG, and IgE antibody responses. The severity of ASNase-induced anaphylaxis was found to be correlated with levels of IgG and IgE, but not IgM. Basophils from immunized mice were able to recognize and activate in response to ASNase ex vivo, and the extent of recognition and activation also correlated with the severity of anaphylaxis observed. Using a multivariable model that included all biomarkers significantly associated with anaphylaxis, independent predictors of ASNase-induced hypersensitivity reactions were found to be ASNase IC levels and ASNase-specific binding to leukocytes or basophils. Consistent with our multivariable analysis, we found that basophil depletion significantly protected mice from ASNase-induced hypersensitivity reactions, supporting that basophils are essential and can be used as a predictive marker of ASNase-induced anaphylaxis. Conclusions: Our study demonstrates the need for using tools that can detect both IC- and IgE-mediated hypersensitivity reactions to mitigate the risk of ASNase-induced hypersensitivity reactions during treatment.


Assuntos
Anafilaxia , Asparaginase , Basófilos , Hipersensibilidade a Drogas , Imunoglobulina E , Animais , Asparaginase/efeitos adversos , Asparaginase/imunologia , Basófilos/imunologia , Basófilos/metabolismo , Camundongos , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade a Drogas/diagnóstico , Anafilaxia/imunologia , Anafilaxia/induzido quimicamente , Imunoglobulina E/imunologia , Imunoglobulina E/sangue , Feminino , Modelos Animais de Doenças , Biomarcadores , Imunoglobulina G/imunologia , Imunoglobulina G/sangue , Antineoplásicos/efeitos adversos
15.
Sci Adv ; 10(14): eadl1884, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38579002

RESUMO

Introducing natural Bouligand structure into synthetics is expected to develop high-performance structural materials. Interfibrous interface is critical to load transfer, and mechanical functionality of bioinspired Bouligand structure yet receives little attention. Here, we propose one kind of hierarchical and reconfigurable interfibrous interface based on moderate orderliness to mechanically reinforce bioinspired Bouligand structure. The interface imparted by moderate alignment of adaptable networked nanofibers hierarchically includes nanofiber interlocking and hydrogen-bonding (HB) network bridging, being expected to facilitate load transfer and structural stability through dynamic adjustment in terms of nanofiber sliding and HB breaking-reforming. As one demonstration, the hierarchical and reconfigurable interfibrous interface is constructed based on moderate alignment of networked bacterial cellulose nanofibers. We show that the resultant bioinspired Bouligand structural material exhibits unusual strengthening and toughening mechanisms dominated by interface-microstructure multiscale coupling. The proposed interfibrous interface enabled by moderate orderliness would provide mechanical insight into the assembly of widely existing networked nanofiber building blocks toward high-performance macroscopic bioinspired structural assemblies.

16.
Front Microbiol ; 15: 1355225, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38572243

RESUMO

Background: Alcoholic liver disease (ALD) is exacerbated by disruptions in intestinal microecology and immune imbalances within the gut-liver axis. The present study assesses the therapeutic potential of combining Akkermansia muciniphila (A. muciniphila) with inosine in alleviating alcohol-induced liver injury. Methods: Male C57BL/6 mice, subjected to a Lieber-DeCarli diet with 5% alcohol for 4 weeks, served as the alcoholic liver injury model. Various analyzes, including quantitative reverse transcription polymerase chain reaction (qRT-PCR), ELISA, immunochemistry, 16S rRNA gene sequencing, and flow cytometry, were employed to evaluate liver injury parameters, intestinal barrier function, microbiota composition, and immune responses. Results: Compared to the model group, the A. muciniphila and inosine groups exhibited significantly decreased alanine aminotransferase, aspartate aminotransferase, and lipopolysaccharide (LPS) levels, reduced hepatic fat deposition and neutrophil infiltration, alleviated oxidative stress and inflammation, and increased expression of intestinal tight junction proteins (Claudin-1, Occludin, and ZO-1). These effects were further pronounced in the A. muciniphila and inosine combination group compared to individual treatments. While alcohol feeding induced intestinal dysbiosis and gut barrier disruption, the combined treatment reduced the abundance of harmful bacteria (Oscillibacter, Escherichia/Shigella, and Alistipes) induced by alcohol consumption, promoting the growth of butyrate-producing bacteria (Akkermansia, Lactobacillus, and Clostridium IV). Flow cytometry revealed that alcohol consumption reduced T regulatory (Treg) populations while increasing those of T-helper (Th) 1 and Th17, which were restored by A. muciniphila combined with inosine treatment. Moreover, A. muciniphila and inosine combination increased the expression levels of intestinal CD39, CD73, and adenosine A2A receptor (A2AR) along with enhanced proportions of CD4+CD39+Treg and CD4+CD73+Treg cells in the liver and spleen. The A2AR antagonist KW6002, blocked the beneficial effects of the A. muciniphila and inosine combination on liver injury in ALD mice. Conclusion: This study reveals that the combination of A. muciniphila and inosine holds promise for ameliorating ALD by enhancing the gut ecosystem, improving intestinal barrier function, upregulating A2AR, CD73, and CD39 expression, modulating Treg cells functionality, and regulating the imbalance of Treg/Th17/Th1 cells, and these beneficial effects are partly A2AR-dependent.

17.
J Agric Food Chem ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38607252

RESUMO

Glycosidically bound linalool plays important roles in the formation of excellent tea flavor, while their enantiomeric distribution in teas and the actual transformations with free linalool are still unclear. In this study, a novel chiral ultrahigh performance liquid chromatography-mass spectrometry/mass spectrometry approach to directly analyze linalyl-ß-primeveroside and linalyl-ß-d-glucopyranoside enantiomers in teas was established and then applied in 30 tea samples. A close transformation relationship existed between the two states of linalool for their consistent dominant configurations (most S-form) and corresponding distribution trend in most teas (r up to 0.81). The acidolysis characterization indicated that free linalool might be slowly released from linalyl-ß-primeveroside with stable enantiomeric ratios during long-term withering of white tea in a weakly acidic environment, along with other isomerized products, e.g., geraniol, nerol, α-terpineol, etc. Furthermore, a novel online thermal desorption-gas chromatography-mass spectrometry approach was established to simulate the pyrolysis releasing of linalyl-ß-primeveroside during tea processing. Interestingly, free linalool was not the selected pyrolysis product of linalyl-ß-primeveroside but rather trans/cis-2,6-dimethyl-2,6-octadiene during the high-fire roasting or baking step of oolong and green teas. The identification of above high-fire chemical marks presented great potential to scientifically evaluate the proper thermal conditions in the practical production of tea.

18.
Inorg Chem ; 63(18): 8418-8425, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38644568

RESUMO

Developing catalysts with high catalytic activity and stability in acidic media is crucial for advancing hydrogen production in proton exchange membrane water electrolyzers (PEMWEs). To this end, a self-supported WO3@RuO2 nanowire structure was grown in situ on a titanium mesh using hydrothermal and ion-exchange methods. Despite a Ru loading of only 0.098 wt %, it achieves an overpotential of 246 mV for the oxygen evolution reaction (OER) at a current density of 10 mA·cm-2 in acidic 0.5 M H2SO4 while maintaining excellent stability over 50 h, much better than that of the commercial RuO2. After the establishment of the WO3@RuO2 heterostructure, a reduced overpotential of the rate-determining step from M-O* to M-OOH* is confirmed by the DFT calculation. Meanwhile, its enhanced OER kinetics are also greatly improved by this self-supported system in the absence of the organic binder, leading to a reduced interface resistance between active sites and electrolytes. This work presents a promising approach to minimize the use of noble metals for large-scale PEMWE applications.

19.
Adv Mater ; 36(26): e2401271, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38549262

RESUMO

The advancement of aqueous micro-supercapacitors offers an enticing prospect for a broad spectrum of applications, spanning from wearable electronics to micro-robotics and sensors. Unfortunately, conventional micro-supercapacitors are characterized by low capacity and slopy voltage profiles, limiting their energy density capabilities. To enhance the performance of these devices, the use of 2D MXene-based compounds has recently been proposed. Apart from their capacitive contributions, these structures can be loaded with redox-active nanowires which increase their energy density and stabilize their operation voltage. However, introducing rigid nanowires into MXene films typically leads to a significant decline in their mechanical properties, particularly in terms of flexibility. To overcome this issue, super stretchable micro-pseudocapacitor electrodes composed of MXene nanosheets and in situ reconstructed Ag nanoparticles (Ag-NP-MXene) are herein demonstrated, delivering high energy density, stable operation voltage of ≈1 V, and fast charging capabilities. Careful experimental analysis and theoretical simulations of the charging mechanism of the Ag-NP-MXene electrodes reveal a dual nature charge storage mechanism involving ad(de)sorption of ions and conversion reaction of Ag nanoparticles. The superior mechanical properties of synthesized films obtained through in situ construction of Ag-NP-MXene structure show an ultra stretchability, allowing the devices to provide stable voltage and energy output even at 100% elongation.

20.
Small ; 20(24): e2308286, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38431926

RESUMO

The prevalence of drug-resistant bacteria presents a significant challenge to the antibiotic treatment of Helicobacter pylori (H. pylori), while traditional antimicrobial agents often suffer from shortcomings such as poor gastric retention, inadequate alleviation of inflammation, and significant adverse effects on the gut microbiota. Here, a selenized chitosan (CS-Se) modified bismuth-based metal-organic framework (Bi-MOF@CS-Se) nanodrug is reported that can target mucin through the charge interaction of the outer CS-Se layer to achieve mucosal adhesion and gastric retention. Additionally, the Bi-MOF@CS-Se can respond to gastric acid and pepsin degradation, and the exposed Bi-MOF exhibits excellent antibacterial properties against standard H. pylori as well as clinical antibiotic-resistant strains. Remarkably, the Bi-MOF@CS-Se effectively alleviates inflammation and excessive oxidative stress by regulating the expression of inflammatory factors and the production of reactive oxygen species (ROS), thereby exerting therapeutic effects against H. pylori infection. Importantly, this Bi-MOF@CS-Se nanodrug does not affect the homeostasis of gut microbiota, providing a promising strategy for efficient and safe treatment of H. pylori infection.


Assuntos
Microbioma Gastrointestinal , Helicobacter pylori , Inflamação , Estruturas Metalorgânicas , Helicobacter pylori/efeitos dos fármacos , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Animais , Inflamação/tratamento farmacológico , Infecções por Helicobacter/tratamento farmacológico , Quitosana/química , Antibacterianos/farmacologia , Antibacterianos/química , Espécies Reativas de Oxigênio/metabolismo , Camundongos
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