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1.
Materials (Basel) ; 17(12)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38930410

RESUMO

The application of carbon fiber-reinforced composite materials in marine engineering is growing steadily. The mechanical properties of unbonded flexible risers using composite tensile armor wire are highly valued. However, the curing process generates a certain amount of internal residual stress. We present a detailed analysis of epoxy resin laminates to assess the impact of thermal, chemical, and mechanical effects on the curing stress and strain. An empirical model that correlates temperature and degree of cure was developed to precisely fit the elastic modulus data of the curing resin. The chemical kinetics of the epoxy resin system was characterized using differential scanning calorimetry (DSC), while the tensile relaxation modulus was determined through a dynamic mechanical analysis. The viscoelastic model was calibrated using the elastic modulus data of the cured resin combining temperature and degree of the curing (thermochemical kinetics) responses. Based on the principle of time-temperature superposition, the displacement factor and relaxation behavior of the material were also accurately captured by employing the same principle of time-temperature superposition. Utilizing the empirical model for degree of cure and modulus, we predicted micro-curing-induced strains in cured composite materials, which were then validated with experimental observations.

2.
Adv Mater ; : e2402160, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38876146

RESUMO

Urea electrosynthesis from co-electrolysis of NO3 - and CO2 (UENC) offers a promising technology for achieving sustainable and efficient urea production. Herein, a diatomic alloy catalyst (CuPd1Rh1-DAA), with mutually isolated Pd and Rh atoms alloyed on Cu substrate, is theoretically designed and experimentally confirmed to be a highly active and selective UENC catalyst. Combining theoretical computations and operando spectroscopic characterizations reveals the synergistic effect of Pd1-Cu and Rh1-Cu active sites to promote the UENC via a tandem catalysis mechanism, where Pd1-Cu site triggers the early C-N coupling and promotes *CO2NO2-to-*CO2NH steps, while Rh1-Cu site facilitates the subsequent protonation step of *CO2NH2 to *COOHNH2 toward the urea formation. Impressively, CuPd1Rh1-DAA assembled in a flow cell presents the highest urea Faradaic efficiency of 72.1% and urea yield rate of 53.2 mmol h-1 gcat -1 at -0.5 V versus RHE, representing nearly the highest performance among all reported UENC catalysts.

3.
Ying Yong Sheng Tai Xue Bao ; 35(5): 1408-1418, 2024 May.
Artigo em Chinês | MEDLINE | ID: mdl-38886440

RESUMO

Antibiotics are widely utilized in agriculture for the prevention and treatment of animal diseases. How-ever, the abuse and overuse of antibiotics progressively increase the risks of antibiotic residues and antibiotic resis-tance. The bioaccumulation and biomagnification of antibiotics through food chains will negatively affect ecological safety, and finally threaten human health. There are many shortages of traditional antibiotic detection techniques, such as complex procedures, complicated operation and time consuming, and thus are difficult to meet the demand of instant, efficient and accurate on-site detection. Therefore, it is crucial to develop rapid detection techniques of antibiotics to manage the application of antibiotics in agriculture. We reviewed the utilization, and management of antibiotics in animal husbandry, residual characteristics, and potential hazards of antibiotics in agricultural products, summarized the advancements in rapid detection techniques of antibiotics in agricultural products over the past five years, compared the advantages and disadvantages of different rapid detection techniques, and prospected the future development in this area. This review would provide a valuable reference to the control and point-of-care test of antibiotics in agricultural products.


Assuntos
Antibacterianos , Produtos Agrícolas , Resíduos de Drogas , Antibacterianos/análise , Resíduos de Drogas/análise , Produtos Agrícolas/química , Produtos Agrícolas/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Animais
4.
Water Res ; 257: 121672, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38705064

RESUMO

The transfer of particulate organic carbon (POC) to dissolved organic carbon (DOC; OC transferP-D) is crucial for the marine carbon cycle. Sediment resuspension driven by hydrodynamic forcing can affect the burial of sedimentary POC and benthic biological processes in marginal sea. However, the role of sediment grain size fraction on OC transferP-D and the subsequent impact on OC cycling remain unknown. Here, we conduct sediment resuspension simulations by resuspending grain-size fractionated sediments (< 20, 20-63, and > 63 µm) into filtered seawater, combined with analyses of OC content, optical characteristics, 13C and 14C isotope compositions, and molecular dynamics simulations to investigate OC transferP-D and its regulations on OC bioavailability under sediment resuspension. Our results show that the relative intensities of terrestrial humic-like OC (refractory DOC) increase in resuspension experiments of < 20, 20-63, and > 63 µm sediments by 0.14, 0.01, and 0.03, respectively, likely suggesting that sediment resuspension drives refractory DOC transfer into seawater. The variations in the relative intensities of microbial protein-like DOC are linked to the change of terrestrial humic-like OC, accompanied by higher DOC content and reactivity in seawater, particularly in finer sediments resuspension experiments. This implies that transferred DOC likely fuels microbial growth, contributing to the subsequent enhancement of DOC bioavailability in seawater. Our results also show that the POC contents increase by 0.35 %, 0.66 %, and 0.93 % in < 20, 20-63, and > 63 µm resuspension experiments at the end of incubation, respectively. This suggests that the re-absorption of OC on particles may be a significant process, but previously unrecognized during sediment resuspension. Overall, our findings suggest that sediment resuspension promotes the OC transferP-D, and the magnitudes of OC transferP-D further influence the DOC and POC properties by inducing microbial production and respiration. These processes significantly affect the dynamics and recycling of biological carbon pump in shallow marginal seas.


Assuntos
Ciclo do Carbono , Carbono , Sedimentos Geológicos , Água do Mar , Sedimentos Geológicos/química , Água do Mar/química , Oceanos e Mares
5.
Dentomaxillofac Radiol ; 53(5): 325-335, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38696751

RESUMO

OBJECTIVES: Currently, there is no reliable automated measurement method to study the changes in the condylar process after orthognathic surgery. Therefore, this study proposes an automated method to measure condylar changes in patients with skeletal class II malocclusion following surgical-orthodontic treatment. METHODS: Cone-beam CT (CBCT) scans from 48 patients were segmented using the nnU-Net network for automated maxillary and mandibular delineation. Regions unaffected by orthognathic surgery were selectively cropped. Automated registration yielded condylar displacement and volume calculations, each repeated three times for precision. Logistic regression and linear regression were used to analyse the correlation between condylar position changes at different time points. RESULTS: The Dice score for the automated segmentation of the condyle was 0.971. The intraclass correlation coefficients (ICCs) for all repeated measurements ranged from 0.93 to 1.00. The results of the automated measurement showed that 83.33% of patients exhibited condylar resorption occurring six months or more after surgery. Logistic regression and linear regression indicated a positive correlation between counterclockwise rotation in the pitch plane and condylar resorption (P < .01). And a positive correlation between the rotational angles in both three planes and changes in the condylar volume at six months after surgery (P ≤ .04). CONCLUSIONS: This study's automated method for measuring condylar changes shows excellent repeatability. Skeletal class II malocclusion patients may experience condylar resorption after bimaxillary orthognathic surgery, and this is correlated with counterclockwise rotation in the sagittal plane. ADVANCES IN KNOWLEDGE: This study proposes an innovative multi-step registration method based on CBCT, and establishes an automated approach for quantitatively measuring condyle changes post-orthognathic surgery. This method opens up new possibilities for studying condylar morphology.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Má Oclusão Classe II de Angle , Côndilo Mandibular , Procedimentos Cirúrgicos Ortognáticos , Humanos , Tomografia Computadorizada de Feixe Cônico/métodos , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/cirurgia , Côndilo Mandibular/diagnóstico por imagem , Feminino , Masculino , Adulto , Adolescente , Adulto Jovem
6.
J Med Chem ; 67(8): 6769-6792, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38620134

RESUMO

The activation of Homo sapiens Casein lysing protease P (HsClpP) by a chemical or genetic strategy has been proved to be a new potential therapy in acute myeloid leukemia (AML). However, limited efficacy has been achieved with classic agonist imipridone ONC201. Here, a novel class of HsClpP agonists is designed and synthesized using a ring-opening strategy based on the lead compound 1 reported in our previous study. Among these novel scaffold agonists, compound 7k exhibited remarkably enhanced proteolytic activity of HsClpP (EC50 = 0.79 ± 0.03 µM) and antitumor activity in vitro (IC50 = 0.038 ± 0.003 µM). Moreover, the intraperitoneal administration of compound 7k markedly suppressed tumor growth in Mv4-11 xenograft models, achieving a tumor growth inhibition rate of 88%. Concurrently, 7k displayed advantageous pharmacokinetic properties in vivo. This study underscores the promise of compound 7k as a significant HsClpP agonist and an antileukemia drug candidate, warranting further exploration for AML treatment.


Assuntos
Antineoplásicos , Desenho de Fármacos , Endopeptidase Clp , Leucemia Mieloide Aguda , Humanos , Animais , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Camundongos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologia , Endopeptidase Clp/metabolismo , Relação Estrutura-Atividade , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Proliferação de Células/efeitos dos fármacos , Camundongos Nus , Camundongos Endogâmicos BALB C
7.
J Chem Neuroanat ; 138: 102424, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38670441

RESUMO

Neuroinflammation associated with microglial activation plays a role in the development of Parkinson's disease (PD). The upregulation of interferon regulatory factor 8 (IRF8) in microglia following peripheral nerve injury has been observed to induce microglial activation. This suggests the potential therapeutic significance of IRF8 in PD. This research aims to explore the effects of IRF8 on the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model and lipopolysaccharide (LPS)-induced neuroinflammation, along with its underlying mechanisms. The study examines the differential expression of IRF8 and its effects on neuropathological changes using a PD mouse model and a PD model established from BV2 cells in vitro. IRF8 was found to be prominently expressed in the substantia nigra pars compacta (SNpc) region of PD mice and LPS-stimulated BV2 cells, while the expression of tyrosine hydroxylase (TH) and dopamine (DA) content in the SNpc region of PD mice was notably reduced. MPTP treatment and LPS stimulation intensified microglial activation, inflammation, and activation of the AMPK/mTOR signaling pathway in vivo and in vitro, respectively. Upon IRF8 silencing in the PD mouse and cell models, the knockdown of IRF8 ameliorated MPTP-induced behavioral deficits, increased the counts of TH and Nissl-positive neurons and DA content, reduced the number of Iba-1-positive microglia, and reduced the content of inflammatory factors, possibly by inhibiting the AMPK/mTOR signaling pathway. Similar outcomes were observed in the PD cell model. In conclusion, the suppression of IRF8 alleviates neuroinflammation through regulating microglial activation in PD models in vivo and in vitro by the AMPK/mTOR signaling pathway.


Assuntos
Fatores Reguladores de Interferon , Camundongos Endogâmicos C57BL , Microglia , Doenças Neuroinflamatórias , Doença de Parkinson , Animais , Microglia/metabolismo , Camundongos , Fatores Reguladores de Interferon/metabolismo , Fatores Reguladores de Interferon/genética , Masculino , Doenças Neuroinflamatórias/metabolismo , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Lipopolissacarídeos , Serina-Treonina Quinases TOR/metabolismo , Técnicas de Silenciamento de Genes , Transdução de Sinais/fisiologia , Parte Compacta da Substância Negra/metabolismo , Parte Compacta da Substância Negra/patologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia
8.
Structure ; 32(7): 941-952.e3, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38677288

RESUMO

Itaconate is a key anti-inflammatory/antibacterial metabolite in pathogen-macrophage interactions that induces adaptive changes in Pseudomonas aeruginosa-exposed airways. However, the impact and mechanisms underlying itaconate metabolism remain unclear. Our study reveals that itaconate significantly upregulates the expression of pyoverdine in P. aeruginosa and enhances its tolerance to tobramycin. Notably, the enzymes responsible for efficient itaconate metabolism, PaIch and PaCcl, play crucial roles in both utilizing itaconate and clearing its toxic metabolic intermediates. By using protein crystallography and molecular dynamics simulations analyses, we have elucidated the unique catalytic center and substrate-binding pocket of PaIch, which contribute to its highly efficient catalysis. Meanwhile, analysis of PaCcl has revealed how interactions between domains regulate the conformational changes of the active sites and binding pockets, influencing the catalytic process. Overall, our research uncovers the significance and mechanisms of PaIch and PaCcl in the efficient metabolism of itaconate by P. aeruginosa.


Assuntos
Proteínas de Bactérias , Domínio Catalítico , Simulação de Dinâmica Molecular , Pseudomonas aeruginosa , Succinatos , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/enzimologia , Succinatos/metabolismo , Succinatos/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Cristalografia por Raios X , Hidroliases/metabolismo , Hidroliases/química , Hidroliases/genética , Ligação Proteica , Sítios de Ligação , Especificidade por Substrato
9.
ACS Nano ; 18(12): 9137-9149, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38470845

RESUMO

Point-of-care monitoring of small molecules in biofluids is crucial for clinical diagnosis and treatment. However, the inherent low degree of recognition of small molecules and the complex composition of biofluids present significant obstacles for current detection technologies. Although nanopore sensing excels in the analysis of small molecules, the direct detection of small molecules in complex biofluids remains a challenge. In this study, we present a method for sensing the small molecule drug gentamicin in whole blood based on the mechanosensitive channel of small conductance in Pseudomonas aeruginosa (PaMscS) nanopore. PaMscS can directly detect gentamicin and distinguish its main components with only a monomethyl difference. The 'molecular sieve' structure of PaMscS enables the direct measurement of gentamicin in human whole blood within 10 min. Furthermore, a continuous monitoring device constructed based on PaMscS achieved continuous monitoring of gentamicin in live rats for approximately 2.5 h without blood consumption, while the drug components can be analyzed in situ. This approach enables rapid and convenient drug monitoring with single-molecule level resolution, which can significantly lower the threshold for drug concentration monitoring and promote more efficient drug use. Moreover, this work also lays the foundation for the future development of continuous monitoring technology with single-molecule level resolution in the living body.


Assuntos
Antibacterianos , Nanoporos , Humanos , Ratos , Animais , Antibacterianos/farmacologia , Gentamicinas , Nanotecnologia , Pseudomonas aeruginosa
10.
J Am Chem Soc ; 146(12): 8528-8535, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38497738

RESUMO

Surface waves are known for their mechanical role in coastal processes that influence the weather and climate. However, their chemical impact, particularly on the transformation of pyrogenic carbon, is poorly understood. Pyrogenic carbon is generally assumed to show negligible postformational alteration of its stable carbon isotope composition. Here we present an electrochemical interaction of pyrogenic carbon with the sprayed seawater microdroplets resulting from wave breaking, driven by the galvanic coupling between the microdroplet water-carbon interfaces and the microdroplet water-vapor interfaces. This enables refractory pyrogenic carbon to rapidly degrade via the oxygenation and mineralization reaction, which makes it ∼2.6‰ enriched in 13C, far exceeding the generally assumed postformation alteration values (<0.5‰) of pyrogenic carbon. The unique chemical dynamics of seawater microdroplets provide new insights into the discrepancy in carbon isotope signatures between riverine and marine black carbon, emphasizing the potential of coastal oceans for carbon sequestration in the global carbon cycle.

11.
BMJ Open ; 14(3): e079544, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38431299

RESUMO

OBJECTIVES: Opioid-free anaesthesia (OFA) has emerged as a promising approach for mitigating the adverse effects associated with opioids. The objective of this study was to evaluate the impact of OFA on postoperative nausea and vomiting (PONV) following video-assisted thoracic surgery. DESIGN: Single-centre randomised controlled trial. SETTING: Tertiary hospital in Shanghai, China. PARTICIPANTS: Patients undergoing video-assisted thoracic surgery were recruited from September 2021 to June 2022. INTERVENTION: Patients were randomly allocated to OFA or traditional general anaesthesia with a 1:1 allocation ratio. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure was the incidence of PONV within 48 hours post-surgery, and the secondary outcomes included PONV severity, postoperative pain, haemodynamic changes during anaesthesia, and length of stay (LOS) in the recovery ward and hospital. RESULTS: A total of 86 and 88 patients were included in the OFA and control groups, respectively. Two patients were excluded because of severe adverse events including extreme bradycardia and epilepsy-like convulsion. The incidence and severity of PONV did not significantly differ between the two groups (29 patients (33.0%) in the control group and 22 patients (25.6%) in the OFA group; relative risk 0.78, 95% CI 0.49 to 1.23; p=0.285). Notably, the OFA approach used was associated with an increase in heart rate (89±17 vs 77±15 beats/min, t-test: p<0.001; U test: p<0.001) and diastolic blood pressure (87±17 vs 80±13 mm Hg, t-test: p=0.003; U test: p=0.004) after trachea intubation. Conversely, the control group exhibited more median hypotensive events per patient (mean 0.5±0.8 vs 1.0±2.0, t-test: p=0.02; median 0 (0-4) vs 0 (0-15), U test: p=0.02) during surgery. Postoperative pain scores, and LOS in the recovery ward and hospital did not significantly differ between the two groups. CONCLUSIONS: Our study findings suggest that the implementation of OFA does not effectively reduce the incidence of PONV following thoracic surgery when compared with traditional total intravenous anaesthesia. The opioid-free strategy used in our study may be associated with severe adverse cardiovascular events. TRIAL REGISTRATION NUMBER: ChiCTR2100050738.


Assuntos
Analgésicos Opioides , Náusea e Vômito Pós-Operatórios , Humanos , Analgésicos Opioides/efeitos adversos , Náusea e Vômito Pós-Operatórios/epidemiologia , Náusea e Vômito Pós-Operatórios/prevenção & controle , Cirurgia Torácica Vídeoassistida/efeitos adversos , China/epidemiologia , Anestesia Geral/efeitos adversos , Dor Pós-Operatória/etiologia
12.
Nucleic Acids Res ; 52(6): 3433-3449, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38477394

RESUMO

The regulation of carbon metabolism and virulence is critical for the rapid adaptation of pathogenic bacteria to host conditions. In Pseudomonas aeruginosa, RccR is a transcriptional regulator of genes involved in primary carbon metabolism and is associated with bacterial resistance and virulence, although the exact mechanism is unclear. Our study demonstrates that PaRccR is a direct repressor of the transcriptional regulator genes mvaU and algU. Biochemical and structural analyses reveal that PaRccR can switch its DNA recognition mode through conformational changes triggered by KDPG binding or release. Mutagenesis and functional analysis underscore the significance of allosteric communication between the SIS domain and the DBD domain. Our findings suggest that, despite its overall structural similarity to other bacterial RpiR-type regulators, RccR displays a more complex regulatory element binding mode induced by ligands and a unique regulatory mechanism.


Assuntos
Proteínas de Bactérias , Pseudomonas aeruginosa , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carbono/metabolismo , Regulação Bacteriana da Expressão Gênica , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/patogenicidade , Virulência/genética , Fatores de Virulência/genética
13.
Phytomedicine ; 128: 155507, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38552430

RESUMO

BACKGROUND: Abnormal activation of astrocytes in the amygdala contributes to anxiety after hemorrhagic shock and resuscitation (HSR). Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB)-associated epigenetic reprogramming of astrocytic activation is crucial to anxiety. A bioactive monomer derived from Epimedium icariin (ICA) has been reported to modulate NF-κB signaling and astrocytic activation. PURPOSE: The present study aimed to investigate the effects of ICA on post-HSR anxiety disorders and its potential mechanism of action. METHODS: We first induced HSR in mice through a bleeding and re-transfusion model and selectively inhibited and activated astrocytes in the amygdala using chemogenetics. Then, ICA (40 mg/kg) was administered by oral gavage once daily for 21 days. Behavioral, electrophysiological, and pathological changes were assessed after HSR using the light-dark transition test, elevated plus maze, recording of local field potential (LFP), and immunofluorescence assays. RESULTS: Exposure to HSR reduced the duration of the light chamber and attenuated open-arm entries. Moreover, HSR exposure increased the theta oscillation power in the amygdala and upregulated NF-κB p65, H3K27ac, and H3K4me3 expression. Contrarily, chemogenetic inhibition of astrocytes significantly reversed these changes. Chemogenetic inhibition in astrocytes was simulated by ICA, but chemogenetic activation of astrocytes blocked the neuroprotective effects of ICA. CONCLUSION: ICA mitigated anxiety-like behaviors induced by HSR in mice via inhibiting astrocytic activation, which is possibly associated with NF-κB-induced epigenetic reprogramming.


Assuntos
Ansiedade , Astrócitos , Flavonoides , Choque Hemorrágico , Animais , Astrócitos/efeitos dos fármacos , Flavonoides/farmacologia , Choque Hemorrágico/tratamento farmacológico , Camundongos , Ansiedade/tratamento farmacológico , Masculino , Ressuscitação/métodos , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Comportamento Animal/efeitos dos fármacos , Tonsila do Cerebelo/efeitos dos fármacos , Epimedium/química
14.
Commun Biol ; 7(1): 295, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461208

RESUMO

Pseudomonas aeruginosa, a common nosocomial pathogen, relies on siderophores to acquire iron, crucial for its survival in various environments and during host infections. However, understanding the molecular mechanisms of siderophore regulation remains incomplete. In this study, we found that the BfmRS two-component system, previously associated with biofilm formation and quorum sensing, is essential for siderophore regulation under high osmolality stress. Activated BfmR directly bound to the promoter regions of pvd, fpv, and femARI gene clusters, thereby activating their transcription and promoting siderophore production. Subsequent proteomic and phenotypic analyses confirmed that deletion of BfmRS reduces siderophore-related proteins and impairs bacterial survival in iron-deficient conditions. Furthermore, phylogenetic analysis demonstrated the high conservation of the BfmRS system across Pseudomonas species, functional evidences also indicated that BfmR homologues from Pseudomonas putida KT2440 and Pseudomonas sp. MRSN12121 could bind to the promoter regions of key siderophore genes and osmolality-mediated increases in siderophore production were observed. This work illuminates a novel signaling pathway for siderophore regulation and enhances our understanding of siderophore-mediated bacterial interactions and community establishment.


Assuntos
Infecções por Pseudomonas , Sideróforos , Humanos , Sideróforos/metabolismo , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Pressão Osmótica , Filogenia , Proteômica , Ferro/metabolismo , Pseudomonas/metabolismo
15.
Mikrochim Acta ; 191(3): 141, 2024 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-38363372

RESUMO

The one-step synthesis of Mn-doped carbon quantum dots (Mn-CPDs) with a high quantum yield (QY = 45%) is reported using the microwave-assisted method. Subsequently, Mn-CPDs were successfully combined with Eu3+ ions to construct an Eu3+@Mn-CPDs fluorescence sensor. The presence of tetracycline (TC) induced a transition of fluorescence emission from blue (434 nm) to red (618 nm), and a robust linear relationship was observed between the ratio of F618 nm / F434 nm and the TC concentration (5 - 50 nmol/L), with a limit of detection (LOD) of 5.76 nmol/L. The underlying mechanism of Eu3+@Mn-CPDs and TC sensing is unveiled as a synergistic effect involving inner filter effect (IFE) and concurrent interactions. Notably, the smartphone-integrated sensing platform based on Eu3+@Mn-CPDs enables rapid and quantitative TC detection within a short time (< 30 s) by monitoring fluorescence color changes, achieving high-detection sensitivities (with a LOD of 6.18 nmol/L). This versatile and efficient sensing platform demonstrates its potential for the determination of TC concentrations in milk, honey, and tap water samples.


Assuntos
Manganês , Pontos Quânticos , Carbono , Polímeros , Smartphone , Antibacterianos , Tetraciclina
16.
J Affect Disord ; 353: 38-47, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38417715

RESUMO

PURPOSE: Previous studies have suggested a potential association between gut microbiota and neurological and psychiatric disorders. However, the causal relationship between gut microbiota and cognitive performance remains uncertain. METHODS: A two-sample Mendelian randomization (MR) study used SNPs linked to gut microbiota (n = 18,340) and cognitive performance (n = 257,841) from recent GWAS data. Inverse-variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode were employed. Heterogeneity was assessed via Cochran's Q test for IVW. Results were shown with funnel plots. Outliers were detected through leave-one-out method. MR-PRESSO and MR-Egger intercept tests were conducted to address horizontal pleiotropy influence. LIMITATIONS: Limited to European populations, generic level, and potential confounding factors. RESULTS: IVW analysis revealed detrimental effects on cognitive perfmance associated with the presence of genus Blautia (P = 0.013, 0.966[0.940-0.993]), Catenibacterium (P = 0.035, 0.977[0.956-0.998]), Oxalobacter (P = 0.043, 0.979[0.960-0.999]). Roseburia (P < 0.001, 0.935[0.906-0.965]), in particular, remained strongly negatively associated with cognitive performance after Bonferroni correction. Conversely, families including Bacteroidaceae (P = 0.043, 1.040[1.001-1.081]), Rikenellaceae (P = 0.047, 1.026[1.000-1.053]), along with genera including Paraprevotella (P = 0.044, 1.020[1.001-1.039]), Ruminococcus torques group (P = 0.016, 1.062[1.011-1.115]), Bacteroides (P = 0.043, 1.040[1.001-1.081]), Dialister (P = 0.027, 1.039[1.004-1.074]), Paraprevotella (P = 0.044, 1.020[1.001-1.039]) and Ruminococcaceae UCG003 (P = 0.007, 1.040[1.011-1.070]) had a protective effect on cognitive performance. CONCLUSIONS: Our results suggest that interventions targeting specific gut microbiota may offer a promising avenue for improving cognitive function in diseased populations. The practical application of these findings has the potential to enhance cognitive performance, thereby improving overall quality of life.


Assuntos
Microbioma Gastrointestinal , Transtornos Mentais , Humanos , Microbioma Gastrointestinal/genética , Análise da Randomização Mendeliana , Qualidade de Vida , Cognição
17.
Mar Pollut Bull ; 199: 115931, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38280293

RESUMO

Understanding Perfluoroalkyl substances (PFASs) spatial distribution in natural environments is crucial due to their environmental persistence and potential bioaccumulation. However, limited research has investigated PFASs spatial distribution at a high resolution, especially in the Guangdong-Hong Kong-Macao Greater Bay Area. Here, we examined the composition and concentration of PFASs in 36 bulk surface sediments and grain-size fractionated sediments from 9 representative sites to determine the spatial distribution characteristics in Shenzhen Bay. We found that ΣPFASs decreased gradually from nearshore area to offshore area (0.680 and 0.297 ng g-1 dw, respectively). Furthermore, PFASs are easily adsorbed on fine-grained sediments, likely due to their chain length and hydrophobicity. We argue that the lateral movement of sediments may transport fine-grained sediments associated with ΣPFASs out of the bay, resulting in the spatial difference in ΣPFASs in Shenzhen Bay. Our findings provide important insights into explore the mechanisms associated with preservation and transport of PFASs.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Poluentes Químicos da Água , Sedimentos Geológicos , Fluorocarbonos/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Rios , China , Ácidos Alcanossulfônicos/análise
18.
Cardiovasc Eng Technol ; 15(1): 39-51, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38191807

RESUMO

OBJECTIVE: Easy access bio-signals are useful for alleviating the shortcomings and difficulties associated with cuff-based and invasive blood pressure (BP) measurement techniques. This study proposes a deep learning model, trained using knowledge distillation, based on photoplethysmographic (PPG) and electrocardiogram (ECG) signals to estimate systolic and diastolic blood pressures. METHODS: The estimation model comprises convolutional layers followed by one bidirectional recurrent layer and attention layers. The training approach involves knowledge distillation, where a smaller model (student model) is trained by leveraging information from a larger model (teacher model). RESULTS: The proposed multistage model was evaluated on 1205 subjects from Medical Information Mart for Intensive Care (MIMIC) III database using the Association for the Advancement of Medical Instrumentation (AAMI) and the standards of the British Hypertension Society (BHS). The results revealed that our model performance achieved grade A in estimating both systolic blood pressure (SBP) and diastolic blood pressure (DBP) and met the requirements of the AAMI standard. After training with knowledge distillation (KD), the model achieved a mean absolute error and standard deviation of 2.94 ± 5.61 mmHg for SBP and 2.02 ± 3.60 mmHg for DBP. CONCLUSION: Our results demonstrate the benefits of the knowledge distillation training method in reducing the number of parameters and improving the predictive accuracy of the blood pressure regression model.


Assuntos
Determinação da Pressão Arterial , Hipertensão , Humanos , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial/métodos , Eletrocardiografia , Sístole
19.
PLoS Pathog ; 20(1): e1011946, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38198506

RESUMO

Pseudomonas aeruginosa is a highly pathogenic bacterium known for its ability to sense and coordinate the production of virulence factors in response to host immune responses. However, the regulatory mechanisms underlying this process have remained largely elusive. In this study, we investigate the two-component system CprRS in P. aeruginosa and unveil the crucial role of the sensor protein CprS in sensing the human host defense peptide LL-37, thereby modulating bacterial virulence. We demonstrate that CprS acts as a phosphatase in the presence of LL-37, leading to the phosphorylation and activation of the response regulator CprR. The results prove that CprR directly recognizes a specific sequence within the promoter region of the HigBA toxin-antitoxin system, resulting in enhanced expression of the toxin HigB. Importantly, LL-37-induced HigB expression promotes the production of type III secretion system effectors, leading to reduced expression of proinflammatory cytokines and increased cytotoxicity towards macrophages. Moreover, mutations in cprS or cprR significantly impair bacterial survival in both macrophage and insect infection models. This study uncovers the regulatory mechanism of the CprRS system, enabling P. aeruginosa to detect and respond to human innate immune responses while maintaining a balanced virulence gene expression profile. Additionally, this study provides new evidence and insights into the complex regulatory system of T3SS in P. aeruginosa within the host environment, contributing to a better understanding of host-microbe communication and the development of novel strategies to combat bacterial infections.


Assuntos
Infecções por Pseudomonas , Pseudomonas aeruginosa , Humanos , Pseudomonas aeruginosa/metabolismo , Infecções por Pseudomonas/genética , Infecções por Pseudomonas/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Virulência , Sistemas de Secreção Tipo III/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica
20.
J Colloid Interface Sci ; 660: 136-146, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38241862

RESUMO

HYPOTHESIS: Ice mitigation has received increasing attention due to the severe safety and economic threats of icing hazards to modern industries. Slippery icephobic surface is a potential ice mitigation approach due to its ultra-low ice adhesion strength, great humidity resistance, and effective delay of ice nucleation. However, this approach currently has limited practical applications because of serious liquid depletion in the icing/de-icing process. EXPERIMENTS: A new strategy of phase change materials (PCM)-impregnation porous metallic structures (PIPMSs) was proposed to develop phase changeable icephobic surfaces in this study, and aimed to solve the rapid depletion via the phase changeable interfacial interactions. FINDINGS: Evaluation of surface icephobicity and interfacial analysis proved that the phase changeable surfaces (PIPMSs) worked as an effective and durable icephobic platform by significantly delaying ice nucleation, providing long-term humid tolerance, low ice adhesion strength of as-prepared samples (less than 5 kPa), and signally improved maintaining capacity of impregnated PCMs (less than 10 % depletion) after 50 icing/de-icing cycles. To explore the interfacial responses, phase change models consisting of the unfrozen quasi-liquid layer and solid lubricant layer at the ice/PIPMSs interfaces were established, and the involved icephobic mechanisms of PIPMSs were studied based on the analysis of interfacial interactions.

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