Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
1.
Nano Lett ; 24(4): 1153-1159, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38232325

RESUMO

Twin structures possess distinct physical and chemical properties by virtue of their specific twin configuration. However, twinning and detwinning processes are not fully understood on the atomic scale. Integrating in situ high resolution transmission electron microscopy and molecular dynamic simulations, we find tensile strain in the asymmetrical 5-fold twins of Au nanoparticles leads to twin boundary migration through dislocation sliding (slipping of an atomic layer) along twin boundaries and dislocation reactions at the 5-fold axis under an electron beam. Migration of one or two layers of twin planes is governed by energy barriers, but overall, the total energy, including surface, lattice strain, and twin boundary energy, is relaxed after consecutive twin boundary migration, leading to a detwinning process. In addition, surface rearrangement of 5-fold twinned nanoparticles can aid in the detwinning process.

2.
Neurobiol Dis ; 190: 106379, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38104911

RESUMO

BACKGROUND: Cognitive impairment is a serious nonmotor symptom in patients with Parkinson's disease (PD). Currently, there are few studies investigating the relationship of serum markers and retinal structural changes with cognitive function in PD. OBJECTIVE: To investigate the relationship between retinal structural changes, serum high mobility group box-1 (HMGB1) levels and cognitive function and motor symptoms in PD patients. METHODS: Eighty-nine participants, including 47 PD patients and 42 healthy subjects, were enrolled. PD patients were divided into Parkinson's disease with normal cognitive (PD-NC), Parkinson's disease with mild cognitive impairment (PD-MCI), and Parkinson's disease with dementia (PDD) groups. The motor and nonmotor symptoms of PD patients were evaluated with clinical scale. Serum HMGB1 levels were detected by enzyme-linked immunosorbent assay (ELISA), and ganglion cell-inner plexiform layer complex (GCIPL) thickness changes in the macula were quantitatively analyzed by swept source optical coherence tomography (SS-OCT) in all patients. RESULTS: Compared with the control group, the macular GCIPL (t = -2.308, P = 0.023) was thinner and serum HMGB1 (z = -2.285, P = 0.022) was increased in PD patients. Macular GCIPL thickness in patients with PD-MCI and PDD were significantly lower than that in PD-NC patients, but there were no significant difference between the PD-MCI and PDD groups. Serum HMGB1 levels in patients with PD-MCI and PDD were significantly higher than those in PD-NC patients, and serum HMGB1 levels in PDD patients were higher than those in PD-MCI patients. Correlation analysis showed that serum HMGB1 levels in PD patients were positively correlated with disease duration, HY stage, UPDRS-I score, UPDRS-III score, and UPDRS total score and negatively correlated with MOCA score. Macular GCIPL thickness was negatively correlated with HY stage and positively correlated with MOCA score, and macular GCIPL thickness was negatively correlated with serum HMGB1 level. Logistic regression analysis showed that elevated serum HMGB1 level, thinner macular GCIPL thickness, and higher HY stage were independent risk factors for Parkinson's disease with cognitive impairment (PD-CI). The areas under the receiver operating characteristic curve (AUC) for the serum HMGB1 level and macular GCIPL thickness-based diagnosis of PD-MCI, PDD and PD-CI based on in patients with PD were 0.786 and 0.825, 0.915 and 0.856, 0.852 and 0.841, respectively. The AUC for the diagnosis of PD-MCI, PDD and PD-CI with serum HMGB1 level and GCIPL thickness combined were 0.869, 0.967 and 0.916, respectively. CONCLUSION: The macular GCIPL thickness and serum HMGB1 level are potential markers of cognitive impairment in PD patients, and their combination can significantly improve the accuracy of the diagnosis of cognitive impairment in PD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Proteína HMGB1 , Doença de Parkinson , Humanos , Cognição , Retina
3.
Eur J Neurosci ; 59(10): 2702-2714, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38469656

RESUMO

This study aims to analyse hyperechoic substantia nigra (HSN) characteristics and the correlation of HSN with clinical features and blood biomarkers in patients with Parkinson's disease (PD). Transcranial sonography (TCS) evaluations of the substantia nigra (SN) were performed in 40 healthy controls and 71 patients with PD, including patients with SN hyperechogenicity (SN+) and those with normal SN echogenicity (SN-). Evaluation of motor and non-motor symptoms was assessed by a series of rating scales. The uricase method was used to determine serum uric acid (UA) levels, and enzyme-linked immunosorbent assay (ELISA) was used to measure plasma interleukin (IL)-1ß levels. TCS showed 92.50% specificity and 61.97% sensitivity in differentiating PD patients from controls. The area of SN+ contralateral to the side of initial motor symptoms (SNcontra) was larger than that ipsilateral to the side of initial motor symptoms (SNipsi). The PDSN+ group had lower Argentine Hyposmia Rating Scale (AHRS) scores and UA levels than the PDSN- group. Binary logistic regression analysis revealed that AHRS scores and UA levels could be independent predictors for HSN. The larger SN echogenic area (SNL) sizes positively correlated with plasma IL-1ß levels in PD patients with SN+. The present study provides further evidence of the potential of SN echogenicity as an imaging biomarker for PD diagnosis. PD patients with HSN have more severe non-motor symptoms of hyposmia. HSN in PD patients is related to the mechanism of abnormal iron metabolism and microglial activation.


Assuntos
Interleucina-1beta , Doença de Parkinson , Substância Negra , Ultrassonografia Doppler Transcraniana , Humanos , Doença de Parkinson/diagnóstico por imagem , Masculino , Feminino , Pessoa de Meia-Idade , Substância Negra/diagnóstico por imagem , Substância Negra/metabolismo , Idoso , Ultrassonografia Doppler Transcraniana/métodos , Interleucina-1beta/sangue , Interleucina-1beta/metabolismo , Ácido Úrico/sangue , Biomarcadores/sangue
4.
Small ; 20(30): e2312216, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38412417

RESUMO

Electrolysis of water has emerged as a prominent area of research in recent years. As a promising catalyst support, copper foam is widely investigated for electrolytic water, yet the insufficient mechanical strength and corrosion resistance render it less suitable for harsh working conditions. To exploit high-performance catalyst supports, various metal supports are comprehensively evaluated, and Ti6Al4V (Ti64) support exhibited outstanding compression and corrosion resistance. With this in mind, a 3D porous Ti64 catalyst support is fabricated using the selective laser sintering (SLM) 3D printing technology, and a conductive layer of nickel (Ni) is coated to increase the electrical conductivity and facilitate the deposition of catalysts. Subsequently, Co0.8Ni0.2(CO3)0.5(OH)·0.11H2O (CoNiCH) nanoneedles are deposited. The resulting porous Ti64/Ni/CoNiCH electrode displayed an impressive performance in the oxygen evolution reaction (OER) and reached 30 mA cm-2 at an overpotential of only 200 mV. Remarkably, even after being compressed at 15.04 MPa, no obvious structural deformation is observed, and the attenuation of its catalytic efficiency is negligible. Based on the computational analysis, the CoNiCH catalyst demonstrated superior catalytic activity at the Ni site in comparison to the Co site. Furthermore, the electrode reached 30 mA cm-2 at 1.75 V in full water splitting conditions and showed no significant performance degradation even after 60 h of continuous operation. This study presents an innovative approach to robust and corrosion-resistant catalyst design.

5.
J Neurosci Res ; 102(2): e25303, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38361408

RESUMO

Lipocalin-2 (LCN2) is essential for the regulation of neuroinflammation and cellular uptake of iron. This study aimed to evaluate plasma LCN2 levels and explore their correlation with clinical and neuroimaging features in Parkinson's disease (PD) patients. Enzyme-linked immunosorbent assay (ELISA) was used to measure plasma LCN2 levels in 120 subjects. Evaluation of motor symptoms and nonmotor symptoms in PD patients was assessed by the associated scales. Voxel-based morphometry (VBM) was used to evaluate brain volume alterations, and quantitative susceptibility mapping (QSM) was used to quantitatively analyze brain iron deposition in 46 PD patients. Plasma LCN2 levels were significantly higher in PD patients than those in healthy controls. LCN2 levels were negatively correlated with Montreal Cognitive Assessment (MoCA) scores, total brain gray matter volume (GMV), and GMV/total intracranial volume (TIV) ratio, but positively correlated with Hamilton Anxiety Rating Scale (HAMD) scores and mean QSM values of the bilateral substantial nigra (SN). Receiver operating characteristic (ROC) curves confirmed that plasma LCN2 levels had good predictive accuracy for PD. The results suggest that plasma LCN2 levels have potential as a biomarker for the diagnosis of PD. LCN2 may be a therapeutic target for neuroinflammation and brain iron deposition.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Lipocalina-2 , Doenças Neuroinflamatórias , Imageamento por Ressonância Magnética/métodos , Neuroimagem , Ferro/metabolismo
6.
Electrophoresis ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38809093

RESUMO

This research examines the electromagnetohydrodynamic (EMHD) flow of Jeffrey fluid in a rough circular microchannel while considering the effect of surface charge on slip. The channel wall corrugations are described as periodic sinusoidal waves with small amplitudes. The perturbation method is employed to derive solutions for velocity and volumetric flow rate, and a combination of three-dimensional (3D) and two-dimensional (2D) graphical representations is utilized to effectively illustrate the impacts of relevant parameters on them. The significance of the Reynolds number R e $Re$ in investigations of EMHD flow is particularly emphasized. Furthermore, the effect of wall roughness ε $\varepsilon $ and wave number k $k$ on velocity and the influence of wall roughness ε $\varepsilon $ and surface charge density σ s ${\sigma }_s$ on volumetric flow rate are primarily focused on, respectively, at various Reynolds numbers. The results suggest that increasing the wall roughness leads to a reduction in velocity at low Reynolds numbers ( R e = 1 $Re = 1$ ) and an increment at high Reynolds numbers ( R e = 10 $Re = 10$ ). For any Reynolds number, a roughness with an odd multiple of wave number ( k = 6 , 10 $k = 6,10$ ) will result in a more stable velocity profile compared to one with an even multiple of wave number ( k = 4 , 8 $k = 4,8$ ). Decreasing the relaxation time λ ¯ 1 ${\bar{\lambda }}_1$ while increasing the retardation time λ ¯ 2 ${\bar{\lambda }}_2$ and Hartmann number H a $Ha$ can diminish the impact of wall roughness ε $\varepsilon $ and surface charge density σ s ${\sigma }_s$ on volumetric flow rate, independent of the Reynolds number. Interestingly, in the existence of wall roughness, further consideration of the effect of surface charge on slip leads to a 15% drop in volumetric flow rate at R e = 1 $Re = 1$ and a 32% slippage at R e = 10 $Re = 10$ . However, in the condition where the effect of surface charge on slip is considered, further examination of the presence of wall roughness only results in a 1.4% decline in volumetric flow rate at R e = 1 $Re = 1$ and a 1.6% rise at R e = 10 $Re = 10$ . These findings are crucial for optimizing the EMHD flow models in microchannels.

7.
Cardiovasc Diabetol ; 23(1): 23, 2024 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-38216931

RESUMO

BACKGROUND: The TyG index, a prominent metric for assessing insulin resistance, has gained traction as a prognostic tool for cardiovascular disease. Nevertheless, the understanding of the prognostic significance of the extent of coronary artery stenosis in individuals afflicted with H-type hypertension remains limited. METHODS: A retrospective study was conducted at Wuhan Third Hospital, including a cohort of 320 inpatients who were diagnosed with hypertension in combination with coronary artery disease. The study period spanned from January 1, 2021, to February 1, 2023. The study cohort was stratified based on the severity of stenosis into three distinct groups: low stenosis, medium stenosis, and high stenosis, as determined by the Gensini score derived from coronary angiography findings. The present study aimed to investigate the association between the severity of coronary stenosis and the number of lesion branches, utilizing the TyG index as a testing indicator. The predictive ability of TyG for coronary lesion severity was assessed using logistic regression analysis. RESULTS: The results of our study indicate a positive correlation between elevated levels of TyG and an increased susceptibility to severe stenosis in individuals diagnosed with H-type hypertension. Upon careful consideration of potential confounding variables, it has been observed that the TyG index exhibits a robust association with the likelihood of severe stenosis in individuals with H-type hypertension (odds ratio [OR] = 4000, 95% confidence interval CI 2.411-6.635, p = 0.0001), as well as the prevalence of multivessel disease (OR = 1.862, 95% CI 1.036-3.348, p < 0.0001). The TyG index demonstrated superior predictive ability for severe coronary stenosis in patients with H-type hypertension compared to those without H-type hypertension (area under the curve [AUC] = 0.888, 95% confidence interval CI 0.838-0.939, p < 0.0001, versus AUC = 0.615, 95% CI 0.494-0.737, p < 0.05). CONCLUSION: The TyG index is an independent risk factor for the degree of coronary stenosis and a better predictor in patients with H-type hypertension combined with coronary artery disease.


Assuntos
Doença da Artéria Coronariana , Estenose Coronária , Hipertensão , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Constrição Patológica , Estudos Retrospectivos , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/epidemiologia , Triglicerídeos , Glucose , Glicemia , Fatores de Risco , Biomarcadores
8.
Scand J Immunol ; 99(5): e13362, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38605563

RESUMO

T cells contribute to the pathogenesis of atherosclerosis. However, the presence and function of granulocyte-macrophage-colony-stimulating factor (GM-CSF)-producing T helper (ThGM) cells in atherosclerosis development is unknown. This study aims to characterize the phenotype and function of ThGM cells in experimental atherosclerosis. Atherosclerosis was induced by feeding apolipoprotein E knockout (ApoE-/-) mice with a high-fat diet. Aortic ThGM cells were detected and sorted by flow cytometry. The effect of oxidized low-density lipoprotein (oxLDL) on ThGM cells and the impact of ThGM cells on macrophages were evaluated by flow cytometry, quantitative RT-PCR, oxLDL binding/uptake assay, immunoblotting and foam cell formation assay. We found that GM-CSF+IFN-γ- ThGM cells existed in atherosclerotic aortas. Live ThGM cells were enriched in aortic CD4+CCR6-CCR8-CXCR3-CCR10+ T cells. Aortic ThGM cells triggered the expression of interleukin-1ß (IL-1ß), tumour necrosis factor (TNF), interleukin-6 (IL-6) and C-C motif chemokine ligand 2 (CCL2) in macrophages. Besides, aortic ThGM cells expressed higher CD69 than other T cells and bound to oxLDL. oxLDL suppressed the cytokine expression in ThGM cells probably via inhibiting the signal transducer and activator of transcription 5 (STAT5) signalling. Furthermore, oxLDL alleviated the effect of ThGM cells on inducing macrophages to produce pro-inflammatory cytokines and generate foam cells. The nuclear receptor subfamily 4 group A (NR4A) members NR4A1 and NR4A2 were involved in the suppressive effect of oxLDL on ThGM cells. Collectively, oxLDL suppressed the supportive effect of ThGM cells on pro-atherosclerotic macrophages.


Assuntos
Aterosclerose , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Lipoproteínas LDL , Macrófagos , Linfócitos T Auxiliares-Indutores , Animais , Camundongos , Aterosclerose/genética , Citocinas/metabolismo , Células Espumosas/patologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Interleucina-6/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Linfócitos T Auxiliares-Indutores/metabolismo
9.
Opt Lett ; 49(15): 4066-4069, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090860

RESUMO

Tin-doped germanium quantum dots (Sn-doped Ge QDs)-decorated hexagonal silicon nanowires (h-Si NWs) were adopted to overcome the low infrared response of silicon and the excess dark current of germanium. High-quality Sn-doped Ge QDs with a narrow bandgap can be achieved through Ge-Sn co-sputtering on silicon nanowires by reducing the contact area between heterojunction materials and Sn-induced germanium crystallization. The absorption limit of the heterostructure is extended to 2.2 µm, and it is sensitive to 375-1550 nm light at 0 V, which has optimality at 1342 nm, with a photo-to-dark current ratio of over 815, a responsivity of 0.154 A/W, and a response time of 0.93 ms. The superior performance of the Sn-doped Ge QDs/h-Si NW photodetector in multiwavelength is attractive for multi-scenario applications.

10.
Cell Commun Signal ; 22(1): 183, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491517

RESUMO

PURPOSE: Prostatitis is a highly prevalent condition that seriously affects men's physical and mental health. Although epidemiological investigations have provided evidence of a correlation between insufficient sleep and prostatitis, the pathogenesis of prostatitis remains unclear. We sought to identify the underlying mechanism involved and identify a promising therapeutic target. METHODS: Sleep deprivation (SD) was utilized to establish a mouse model of insufficient sleep in a special device. Prostatitis was observed at different time points post-SD. The degree of prostatitis was evaluated by pathological section and behavioural tests. Using immunofluorescence, western blot, and proteomic analyses, the underlying mechanism of SD-related prostatitis was investigated, and the development and therapeutic target of prostatitis were elucidated. RESULTS: SD, as an initial pathological trigger, resulted in a reduction in dihydrotestosterone and melatonin levels. Proteomic analysis revealed that the cGAS-STING pathway may play a significant role in inducing prostatitis. The subsequent results illustrated that the dual reduction in dihydrotestosterone and melatonin led to an accumulation of reactive oxygen species and the release of mitochondrial DNA (mt-DNA). The accumulation of mt-DNA activated the cGAS-STING pathway, which recruited inflammatory cells into the prostatic stroma through the secretion of interferon-ß. Consequently, an inflammatory microenvironment was formed, ultimately promoting the development of prostatitis. Notably, mice with SD-induced prostatitis gradually recovered to a normal state within 7 days of recovery sleep. However, after being subjected to SD again, these mice tended to have a more pronounced manifestation of prostatitis within a shorter timeframe, which suggested that prostatitis is prone to relapse. CONCLUSIONS: The cGAS-STING pathway activated by dual deficiency of dihydrotestosterone and melatonin plays a comprehensive inflammatory role in SD-related prostatitis. This research provides valuable insights into the pathogenesis, therapeutic targets, and prevention strategies of prostatitis.


Assuntos
Melatonina , Prostatite , Humanos , Masculino , Animais , Camundongos , Privação do Sono/complicações , Di-Hidrotestosterona/farmacologia , Proteômica , Sono , DNA Mitocondrial , Nucleotidiltransferases
11.
Arch Microbiol ; 206(3): 102, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38353788

RESUMO

A plant growth hormone indoleacetic acid-producing strain LX3-4T was isolated from a carrot rhizosphere soil sample collected in Shandong Province, China. It is Gram-stain-positive, non-motile, and has irregular short rod-shaped cells. LX3-4T shared high 16S rRNA gene sequence identity with Microbacterium oleivorans DSM 16091T (99.4%), M. testaceum NBRC 12675T (98.6%), M. marinum DSM 24947T (98.5%), M. resistens NBRC 103078T (98.4%), and M. paraoxydans NBRC 103076T (98.3%). Phylogenetic analysis based on the concatenated gene sequences of 16S rRNA gene, housekeeping genes gryB and rpoB also showed the distinction between strain LX3-4T and other Microbacterium species. Furthermore, analysis of the average nucleotide identities (ANI), the average amino acid identity (AAI), and the digital DNA-DNA hybridization (dDDH) values between strain LX3-4T and its relatives revealed that strain LX3-4T represents a distinct species. The genomic DNA G + C content of the strain is 69.5%. It can grow at 25-37 °C (optimum 37 °C), pH 5.0-10.0 (optimum pH 6.0-8.0), and the range of NaCl concentration is 0-7% (w/v) (optimum 1-5%). The colonies on agar plates are smooth, translucent, and pale yellow. The main cellular fatty acids of strain LX3-4T are anteiso-C15:0, anteiso-C17:0, and iso-C16:0. The predominant respiratory quinones are MK-12 and MK-11. Diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid, and an unidentified phosphoglycolipid are major polar lipids. The cell-wall sugar of strain LX3-4T is glucose. The cell-wall peptidoglycan contains glycine, alanine, lysine, and glutamic acid. In addition, this strain carries nitrogen fixation genes and can grow in nitrogen-free medium. Based on the polyphasic data, strain LX3-4T represents a novel species of the genus Microbacterium, for which the name Microbacterium dauci sp. nov. is proposed with strain LX3-4T (= CCTCC AB 2023103T = LMG 33159T) designated as the type strain.


Assuntos
Daucus carota , Hormônio do Crescimento , Reguladores de Crescimento de Plantas , Microbacterium , Filogenia , RNA Ribossômico 16S/genética , Rizosfera , Ácidos Indolacéticos , DNA
12.
Clin Exp Rheumatol ; 2024 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-38819961

RESUMO

OBJECTIVES: This study aimed to evaluate the clinical significance of the coexistence of 2 or more myositis-specific antibodies (multiple MSAs) in adult patients with idiopathic inflammatory myopathies (IIM). METHODS: We assessed a cohort of 202 consecutive patients with IIM. Clinical features and survival rates were compared between patients with and without multiple MSAs. RESULTS: Of those 202 patients, 44 (21.8%) were found to have multiple MSAs. 63.6% of the 44 patients tested positive for anti-aminoacyl-tRNA synthetase antibodies (anti-ARS+) and 52.3% positive for anti-melanoma differentiation-associated protein-5 antibody (anti-MDA5+). The presence of multiple MSAs was associated with less rapidly progressive interstitial lung disease (RP-ILD), fever, rash, periungual erythema, more muscle involvement and dysphagia, higher albumin level, and higher positive rate of ANA antibody in anti-MDA5+ population. In anti-ARS+ population with multiple MSAs, there were more V-neck sign, skin ulcers, dysphagia and peripheral edema. No differences in survival rates were observed between patients with or without multiple MSAs in the overall and anti-ARS+ populations. However, the survival rate in anti-MDA5+ population with multiple MSAs was significantly higher than those without multiple MSAs (p = 0.003). Moreover, multiple MSAs remained an independent protective factor against mortality in multivariable Cox regression analysis of anti-MDA5+ population [HR 0.108 (95% CI 0.013, 0.908), p=0.041]. CONCLUSIONS: Multiple MSAs coexist in some IIM patients and their existence indicates mixed features from concomitant MSAs in anti-MDA5+ population and anti-ARS+ population. Identifying multiple MSAs could help to discover a more favourable disease phenotype with decreased mortality in anti-MDA5+ population.

13.
Inorg Chem ; 63(19): 8948-8957, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38687980

RESUMO

Excellent electrocatalytic CO2 reduction reaction activity has been demonstrated by transition metals and nitrogen-codoped carbon (M-N-C) catalysts, especially for transition-metal porphyrin (MTPP)-based catalysts. In this work, we propose to use one-step low-temperature pyrolysis of the isostructural MTPP-based metal-organic frameworks (MOFs) and electrochemical in situ reduction strategies to obtain a series of hybrid catalysts of Co nanoparticles (Co NPs) and MTPP, named Co NPs/MTPP (M = Fe, Co, and Ni). The in situ introduction of Co NPs can efficiently enhance the electrocatalytic ability of MTPP (M = Fe, Co, and Ni) to convert CO2 to CO, particularly for FeTPP. Co NPs/FeTPP endowed a high CO faradaic efficiency (FECOmax = 95.5%) in the H cell, and the FECO > 90.0% is in the broad potential range of -0.72 to -1.22 VRHE. In addition, the Co NPs/FeTPP achieved 145.4 mA cm-2 at a lower potential of -0.70 VRHE with an FECO of 94.7%, and the CO partial currents increased quickly to reach 202.2 mA cm-2 at -0.80 VRHE with an FECO of 91.6% in the flow cell. It is confirmed that Co NPs are necessary for hybrid catalysts to get superior electrocatalytic activity; Co NPs also can accelerate H2O dissociation and boost the proton supply capacity to hasten the proton-coupled electron-transfer process, effectively adjusting the adsorption strength of the reaction intermediates.

14.
BMC Vet Res ; 20(1): 110, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500105

RESUMO

BACKGROUND: Traumatic brain injury (TBI) is a common condition in veterinary medicine that is difficult to manage.Veterinary regenerative therapy based on adipose mesenchymal stem cells seem to be an effective strategy for the treatment of traumatic brain injury. In this study, we evaluated therapeutic efficacy of canine Adipose-derived mesenchymal stem cells (AD-MSCs)in a rat TBI model, in terms of improved nerve function and anti-neuroinflammation. RESULTS: Canine AD-MSCs promoted neural functional recovery, reduced neuronal apoptosis, and inhibited the activation of microglia and astrocytes in TBI rats. According to the results in vivo, we further investigated the regulatory mechanism of AD-MSCs on activated microglia by co-culture in vitro. Finally, we found that canine AD-MSCs promoted their polarization to the M2 phenotype, and inhibited their polarization to the M1 phenotype. What's more, AD-MSCs could reduce the migration, proliferation and Inflammatory cytokines of activated microglia, which is able to inhibit inflammation in the central system. CONCLUSIONS: Collectively, the present study demonstrates that transplantation of canine AD-MSCs can promote functional recovery in TBI rats via inhibition of neuronal apoptosis, glial cell activation and central system inflammation, thus providing a theoretical basis for canine AD-MSCs therapy for TBI in veterinary clinic.


Assuntos
Lesões Encefálicas Traumáticas , Doenças do Cão , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Doenças dos Roedores , Ratos , Animais , Cães , Lesões Encefálicas Traumáticas/terapia , Lesões Encefálicas Traumáticas/veterinária , Microglia , Macrófagos , Inflamação/veterinária , Transplante de Células-Tronco Mesenquimais/veterinária , Transplante de Células-Tronco Mesenquimais/métodos
15.
Sensors (Basel) ; 24(15)2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39123919

RESUMO

To improve the accuracy of in situ measurement of the standard volumes of pipe provers and to shorten the traceability chain, a new method of in situ pipe prover volume measurement was developed alongside a supporting measurement device. This method is based on the geometric dimension approach, which measures the inner diameter and length of a pipe prover to calculate its volume. For inner diameter measurement, a three-probe inner-diameter algorithm model was established. This model was calibrated using a standard ring gauge of Φ313 mm, with the parameters calculated through fitting. Another standard ring gauge of Φ320 mm was used to verify the inner diameters determined by the algorithmic model. A laser interferometer was employed for the segmented measurement of the pipe prover length. The comprehensive measurement system was then used for in situ measurement of the standard pipe prover. The newly developed system achieved an expanded uncertainty of 0.012% (k = 2) in volume measurement, with the deviation between the measured and nominal pipe prover volumes being merely 0.007%. These results demonstrate that the proposed in situ measurement method offers ultra-high-precision measurement capabilities.

16.
Angew Chem Int Ed Engl ; 63(32): e202406552, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38766881

RESUMO

Triply interlocked [2]catenane complexes featuring two identical, mechanically interlocked units are extraordinarily rare chemical compounds, whose properties and applications remain open to detailed studies. Herein, we introduce the rational design of a new ligand precursor, L1, suitable for the synthesis of six triply interlocked [2]catenanes by coordination-driven self-assembly. The interlocked compounds can be reversibly converted into the corresponding simple triangular prism metallacage by addition of H2O or DMF solvents to their CH3OH solutions, thereby demonstrating the importance of π⋅⋅⋅π stacking and hydrogen bonding interactions in the formation of triply interlocked [2]catenanes. Moreover, extensive studies have been conducted to assess the remarkable photothermal conversion performance. Complex 6 a, exhibiting outstanding photothermal conversion performance (conversion efficiency in solution : 31.82 %), is used to prepare novel photoresponsive elastomer in combination with thermally activated liquid crystal elastomer. The resultant material displays robust response to near-infrared (NIR) laser and the capability of completely reforming the shape and reversible actuation, paving the way for the application of half-sandwich organometallic units in photo-responsive smart materials.

17.
Cell Mol Biol (Noisy-le-grand) ; 69(13): 102-105, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38158681

RESUMO

The objective of this study was to analyze the effect of curcumin (Cur) on pulmonary fibrosis (PF), so as to provide new clinical evidence for future PF treatment. To achieve these goals, the researchers set up bought human lung fibroblasts MRC-5 as a control group without treatment, a model group for PF cell modeling, and an intervention group for Cur intervention after PF modeling. Cell proliferation capacity and cellular TGF-ß1, α-SMA, Collagen I, Collagen III, Bax, N-cadherin and E-cadherin protein expression were determined. The results show that markedly enhanced cell proliferation capacity and TGF-ß1, α-SMA, Collagen I and Collagen III protein levels were observed in the model group, while the cell activity and fibrosis degree in the intervention group were significantly decreased compared with the model group (P<0.05). In addition, the intervention group exhibited lower N-cadherin and Bax with higher E-cadherin than the model group (P<0.05). In addition, the team found that the inflammatory response and oxidative stress were also more significantly improved in the intervention group (P<0.05). These experimental results tell us that Cur can ameliorate the fibrotic process of PF by inhibiting the activity of MRC-5.


Assuntos
Curcumina , Fibrose Pulmonar , Humanos , Fibrose Pulmonar/tratamento farmacológico , Fator de Crescimento Transformador beta1/metabolismo , Curcumina/farmacologia , Curcumina/uso terapêutico , Curcumina/metabolismo , Proteína X Associada a bcl-2/metabolismo , Fibrose , Pulmão/patologia , Colágeno/metabolismo , Fibroblastos/metabolismo , Colágeno Tipo I/metabolismo , Colágeno Tipo I/farmacologia , Colágeno Tipo I/uso terapêutico , Caderinas/metabolismo
18.
Materials (Basel) ; 17(12)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38930164

RESUMO

Orthotropic steel decks (OSDs) are commonly used in the construction of bridges due to their load-bearing capabilities. However, they are prone to fatigue damage over time due to the cyclic loads from vehicles. Therefore, the early structural health monitoring of fatigue damage in OSDs is crucial for ensuring bridge safety. Moreover, Lamb waves, as elastic waves propagating in OSD plate-like structures, are characterized by their long propagation distances and minimal attenuation. This paper introduces a method of emitting high-energy ultrasonic waves onto the OSD surface to capture the nonlinear Lamb waves formed, thereby calculating the nonlinear parameters. These parameters are then correlated with the fatigue damage endured, forming a damage index (DI) for monitoring the fatigue life of OSDs. Experimental results indicate that as fatigue damage increases, the nonlinear parameters exhibit a significant initial increase followed by a decrease. The behavior is distinct from the characteristic parameters of linear ultrasound (velocity and energy), which also exhibit changes but to a relatively smaller extent. The proposed DI and fatigue life based on nonlinear parameters can be fitted with a Gaussian curve, with the R-squared value of the fitting curve being close to 1. Additionally, this paper discusses the influence of rib welds within the OSDs on the DI, whereby as fatigue damage increases, it enlarges the value of the nonlinear parameters without altering their trend. The proposed method provides a more effective approach for monitoring early fatigue damage in OSDs.

19.
Nat Commun ; 15(1): 4461, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796491

RESUMO

Behaving efficiently and flexibly is crucial for biological and artificial embodied agents. Behavior is generally classified into two types: habitual (fast but inflexible), and goal-directed (flexible but slow). While these two types of behaviors are typically considered to be managed by two distinct systems in the brain, recent studies have revealed a more sophisticated interplay between them. We introduce a theoretical framework using variational Bayesian theory, incorporating a Bayesian intention variable. Habitual behavior depends on the prior distribution of intention, computed from sensory context without goal-specification. In contrast, goal-directed behavior relies on the goal-conditioned posterior distribution of intention, inferred through variational free energy minimization. Assuming that an agent behaves using a synergized intention, our simulations in vision-based sensorimotor tasks explain the key properties of their interaction as observed in experiments. Our work suggests a fresh perspective on the neural mechanisms of habits and goals, shedding light on future research in decision making.


Assuntos
Teorema de Bayes , Objetivos , Hábitos , Humanos , Intenção , Tomada de Decisões/fisiologia , Encéfalo/fisiologia
20.
Int J Biol Macromol ; 274(Pt 1): 133365, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38914410

RESUMO

PLA is widely known as biodegradable plastics whose further application in fields such as automotive and architectural is still constrained by its flammability and unsatisfactory crystallization properties. To address the aforementioned concerns, a novel biomass phosphonamide PDPA was synthesized with chemical structure confirmed by FTIR, NMR and elemental analysis tests. Immediately thereafter, PLA/PDPA composites were prepared by melting blending, with a focus on flame retardancy, crystallization properties and flame-retardant mechanism. As expected, PDPA efficiently enhanced both the flame retardancy and crystallization properties of PLA. Specifically, the PLA/4.0PDPA obtained UL-94 V-0 grade and the LOI value increased to 28.6 % with only 4 wt% PDPA added, which comes down to the superior free radical capture and dilution effect of PDPA in the vapor phase and the melting droplet effect. More appealingly, the crystallinity of PLA/4.0PDPA was significantly enhanced to 43.4 % from 2.5 % of PLA, and the shortest t1/2 was 4 mins in the isothermal crystallization process due to the excellent heterogeneous nucleation of PDPA. Moreover, PLA/PDPA composites maintain almost the same mechanical performance as pure PLA. In brief, this work provides a green strategy for the preparation of PLA composites with excellent comprehensive performance and shows great potential in engineering materials.


Assuntos
Biomassa , Cristalização , Retardadores de Chama , Poliésteres , Poliésteres/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA