Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; 20(22): e2308419, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38102103

RESUMO

The unsatisfactory oxygen evolution reaction (OER) activity of IrO2 has intensively raised the cost and energy consumption of hydrogen generation from proton exchange membrane water electrolyzers. Here, the acidic OER activity of the rutile IrO2 is significantly enhanced by the incorporation of trivalent metals (e.g., Gd, Nd, and Pr) to increase the Ir-O covalency, while the high-valence (pentavalent or higher) metal incorporation decreases the Ir-O covalency resulting in worse OER activity. Experimental and theoretical analyses indicate that enhanced Ir-O covalency activates lattice oxygen and triggers lattice oxygen-mediated mechanism to enhance OER kinetics, which is verified by the finding of a linear relationship between the natural logarithm of intrinsic activity and Ir-O covalency described by charge transfer energy. By regulating the Ir-O covalency, the obtained Gd-IrO2-δ merely needs 260 mV of overpotential to reach 10 mA cm-2 and shows impressive stability during a 200-h test in 0.5 м H2SO4. This work provides an effective strategy for significantly enhancing the OER activity of the widely used IrO2 electrocatalysts through the rational regulation of Ir-O covalency.

2.
Small ; 20(15): e2308053, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38009478

RESUMO

The urgent development of effective electrocatalysts for hydrogen evolution and hydrogen oxidation reaction (HER/HOR) is needed due to the sluggish alkaline hydrogen electrocatalysis. Here, an unusual face-centered cubic (fcc) Ru nanocrystal with favorable HER/HOR performance is offered. Guided by the lower calculated surface energy of fcc Ru than that of hcp Ru in NH3, the carbon-supported fcc Ru electrocatalyst is facilely synthesized in the NH3 reducing atmosphere. The specific HOR kinetic current density of fcc Ru can reach 23.4 mA cmPGM -2, which is around 20 and 21 times greater than that of hexagonal close-packed (hcp) Ru and Pt/C, respectively. Additionally, the HER specific activity is enhanced more than six times in fcc Ru electrocatalyst when compared to Pt/C. Experimental and theoretical analysis indicate that the phase transition from hcp Ru to fcc Ru can negatively shift the d band center, weaken the interaction between catalysts and key intermediates and therefore enhances the HER/HOR kinetics.

3.
Small ; 20(31): e2400381, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38639308

RESUMO

Pt-based intermetallic compounds (IMCs) are considered as a class of promising fuel cell electrocatalysts, owing to their outstanding intrinsic activity and durability. However, the synthesis of uniformly dispersed IMCs with small sizes presents a formidable challenge during the essential high-temperature annealing process. Herein, a facile and generally applicable VOx matrix confinement strategy is demonstrated for the controllable synthesis of ordered L10-PtM (M = Fe, Co, and Mn) nanoparticles, which not only enhances the dispersion of intermetallic nanocrystals, even at high loading (40 wt%), but also simplifies the oxide removal and acid-washing procedures. Taking intermetallic PtCo as an example, the as-prepared catalyst displays a high-performance oxygen reduction activity (mass activity of 1.52 A mgPt -1) and excellent stability in the membrane electrode assemblies (MEAs) (the ECSA has just 7% decay after durability test). This strategy provides an economical and scalable route for the controlled synthesis of Pt-based intermetallic catalysts, which can pave a way for the commercialization of fuel cell technologies.

4.
Opt Express ; 32(5): 8308-8320, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38439489

RESUMO

Conventional photoacoustic endoscopy (PAE) is mostly for structural imaging, and its molecular imaging ability is quite limited. In this work, we address this issue and present the development of a flexible acoustic-resolution-based photoacoustic endoscopic (AR-PAE) probe with an outer diameter of 8 mm. This probe is driven by a micro-step motor at the distal end, enabling flexible and precise angular step control to synchronize with the optical parametric oscillator (OPO) lasers. This probe retains the high spatial resolution, high penetration depth, and spectroscopic imaging ability of conventional AR-PAE. Moreover, it is capable for background-free high-specific photoacoustic molecular imaging with a novel pump-probe detection technique, as demonstrated by the distribution visualizing of the FDA approved contrast agent methylene blue (MB) in an ex-vivo pig ileum. This proposed method represents an important technical advancement in multimodal PAE, and can potentially make considerable contributions across various biomedical fields.


Assuntos
Endoscópios , Imagem Molecular , Animais , Suínos , Análise Espectral , Meios de Contraste , Azul de Metileno
5.
Nano Lett ; 23(11): 5187-5193, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37276263

RESUMO

Intermetallic compounds, featuring atomically ordered structures, have emerged as a class of promising electrocatalysts for fuel cells. However, it remains a formidable challenge to controllably synthesize Pt-based intermetallics during the essential high-temperature annealing process as well as stabilize the nanoparticles (NPs) during the electrocatalytic process. Herein, we demonstrated a Ketjen black supported intermetallic Pt3Ti nanocatalyst coupled with amorphous TiOx species (Pt3Ti-TiOx/KB). The TiOx can not only confine Pt3Ti NPs during the synthesis and electrocatalytic process by a strong metal-oxide interaction but also promote the water dissociation for generating more OH species, thus facilitating the conversion of COad. The Pt3Ti-TiOx/KB showed a significantly enhanced mass activity (2.15 A mgPt-1) for the methanol oxidation reaction, compared with Pt3Ti/KB and Pt/C, and presented an impressively high mass activity retention (∼71%) after the durability test. This work provides an effective strategy of coupling Pt-based intermetallics with functional oxides for developing highly performed electrocatalysts.

6.
Int J Mol Sci ; 25(12)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38928450

RESUMO

Abnormal cell proliferation and growth leading to cancer primarily result from cumulative genome mutations. Single gene mutations alone do not fully explain cancer onset and progression; instead, clustered mutations-simultaneous occurrences of multiple mutations-are considered to be pivotal in cancer development and advancement. These mutations can affect different genes and pathways, resulting in cells undergoing malignant transformation with multiple functional abnormalities. Clustered mutations influence cancer growth rates, metastatic potential, and drug treatment sensitivity. This summary highlights the various types and characteristics of clustered mutations to understand their associations with carcinogenesis and discusses their potential clinical significance in cancer. As a unique mutation type, clustered mutations may involve genomic instability, DNA repair mechanism defects, and environmental exposures, potentially correlating with responsiveness to immunotherapy. Understanding the characteristics and underlying processes of clustered mutations enhances our comprehension of carcinogenesis and cancer progression, providing new diagnostic and therapeutic approaches for cancer.


Assuntos
Carcinogênese , Mutação , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/patologia , Carcinogênese/genética , Instabilidade Genômica , Transformação Celular Neoplásica/genética , Reparo do DNA/genética , Animais
7.
J Environ Manage ; 370: 122908, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39405871

RESUMO

Bisphenol A (BPA), a pervasive substance in our daily lives and livestock excreta, poses significant threats due to its infiltration into foods and water sources. BPA has adverse impacts on male reproductive function, particularly affecting the critical Sertoli (ST) cells that play a pivotal role in the process of spermatogonia differentiating into spermatozoa. In this study, we examined the prevalence of BPA within the pig industry and delved into the impact of BPA exposure on the motility of boar sperm, the function of pig ST cells, as well as the underlying molecular mechanisms involved. This study revealed spatial disparities in the global distribution of BPA and its analogue contamination, utilizing data compiled from 130 comprehensive studies. The average concentration of BPA found in pig feed ranges from 9.7 to 47.9 µg/kg, while in serum, it averages between 55.1 and 75.6 ng/L. The BPA concentration in feed exhibits a negative correlation with sperm viability and the percentage of progressive motile spermatozoa. Exposure to BPA reduced sperm motility in boar and ST cell activity at both 6 and 24 h. The transcriptome analysis revealed that, compared to untreated control cells, endoplasmic reticulum stress (ERS)-related genes were upregulated in ST cells exposed to BPA at 6 and 24 h. This activation of ERS in ST cells was mediated by receptor protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring protein-1α (IRE1α), and activating transcription factor 6 (ATF6). Additionally, BPA exposure triggered oxidative stress and a proinflammatory response mediated by the transcription factor NF-κB, accompanied by an increase in downstream proinflammatory cytokines. BPA exposure also led to apoptosis in ST cells and upregulated the expression levels of pro-apoptosis proteins. However, inhibiting ERS activity with 4-PBA attenuated the BPA-induced inflammatory response and apoptosis in ST cells. Our findings suggest that BPA induced apoptosis and inflammatory response in porcine ST cells through persistent activation of ERS, thereby compromising the normal function of these cells.

8.
Molecules ; 29(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38398537

RESUMO

Proton exchange membrane water electrolysis is hindered by the sluggish kinetics of the anodic oxygen evolution reaction. RuO2 is regarded as a promising alternative to IrO2 for the anode catalyst of proton exchange membrane water electrolyzers due to its superior activity and relatively lower cost compared to IrO2. However, the dissolution of Ru induced by its overoxidation under acidic oxygen evolution reaction (OER) conditions greatly hinders its durability. Herein, we developed a strategy for stabilizing RuO2 in acidic OER by the incorporation of high-valence metals with suitable ionic electronegativity. A molten salt method was employed to synthesize a series of high-valence metal-substituted RuO2 with large specific surface areas. The experimental results revealed that a high content of surface Ru4+ species promoted the OER intrinsic activity of high-valence doped RuO2. It was found that there was a linear relationship between the ratio of surface Ru4+/Ru3+ species and the ionic electronegativity of the dopant metals. By regulating the ratio of surface Ru4+/Ru3+ species, incorporating Re, with the highest ionic electronegativity, endowed Re0.1Ru0.9O2 with exceptional OER activity, exhibiting a low overpotential of 199 mV to reach 10 mA cm-2. More importantly, Re0.1Ru0.9O2 demonstrated outstanding stability at both 10 mA cm-2 (over 300 h) and 100 mA cm-2 (over 25 h). The characterization of post-stability Re0.1Ru0.9O2 revealed that Re promoted electron transfer to Ru, serving as an electron reservoir to mitigate excessive oxidation of Ru sites during the OER process and thus enhancing OER stability. We conclude that Re, with the highest ionic electronegativity, attracted a mass of electrons from Ru in the pre-catalyst and replenished electrons to Ru under the operating potential. This work spotlights an effective strategy for stabilizing cost-effective Ru-based catalysts for acidic OER.

9.
Angew Chem Int Ed Engl ; : e202411123, 2024 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-39370396

RESUMO

Advancing the design of cathode catalysts to significantly maximize platinum utilization and augment the longevity has emerged as a formidable challenge in the field of fuel cells. Herein, we rationally design a high entropy intermetallic compound (HEIC, Pt(FeCoNiCu)3) for catalyzing oxygen reduction reaction (ORR) by an efficient machine learning stategy, where crystal graph convolutional neural networks are employed to expedite the multicomponent design. Based on a dataset generated from first-principles calculations, the model can achieve a high prediction accuracy with mean absolute errors of 0.003 for surface strain and 0.011 eV atom-1 for formation energy. In addition, we identify two chemical features (atomic size difference and mixing enthalpy) as new descriptors to explore advanced ORR catalysts. The carbon supported Pt(FeCoNiCu)3 catalyst with small particle size is successfully synthesized by a freeze-drying-annealing technology, and exhibits ultrahigh mass activity (4.09 A mgPt-1) and specific activity (7.92 mA cm-2). Meanwhile, The catalyst also shows significantly enhanced electrochemical stability which can be ascribed to the sluggish difussion effect in the HEIC structure. Beyond offering a promising low-Pt electrocatalysts for fuel cell cathode, this work offers a new paradigm to rationally design advanced catalysts for energy storage and conversion devices.

10.
Cancer Sci ; 114(4): 1740-1756, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36478492

RESUMO

Limb expression 1-like protein (LIX1L) might be an RNA-binding protein involved in post-transcriptional regulation. However, little is known regarding the biological function and mechanism of LIX1L in cancer cells. Here we demonstrate a clear correlation between LIX1L expression and epithelial-mesenchymal transition (EMT) markers in 81 non-small cell lung cancer (NSCLC) tissues and The Cancer Genome Atlas database, suggesting that LIX1L is a mesenchymal marker. Besides, LIX1L expression is obviously elevated in TGFß1-induced EMT NSCLC cells and enhances cell migration, invasion, anoikis resistance, epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) resistance, and proliferation. Interestingly, the increased LIX1L expression prominently localizes to the nucleoli, where it physically interacts with the key ribosome biogenesis regulator NCL protein, inducing ribosomal RNA (rRNA) synthesis in EMT NSCLC cells. NCL knockdown or inhibition of rRNA synthesis reverses the enhanced EMT functions and proliferation ability caused by LIX1L overexpression in NSCLC cells, indicating that NCL expression and rRNA synthesis participates in LIX1L-mediated biological functions during EMT. Collectively, our findings suggest that the LIX1L-NCL-rRNA synthesis axis is a novel EMT-activated mechanism. Targeting the pathway might be a therapeutic option for EMT and EGFR-TKI resistance in NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal/genética , Receptores ErbB , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Ribossomos/metabolismo , RNA Ribossômico/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Relacionadas à Autofagia/metabolismo , Nucleolina
11.
BMC Cancer ; 23(1): 1230, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097995

RESUMO

BACKGROUND: This study aimed to investigate the differences in the clinicopathological characteristics of younger and older patients with endometrial cancer (EC) and develop a nomogram to assess the prognosis of early onset EC in terms of overall survival. METHODS: Patients diagnosed with EC from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015 were selected. Clinicopathological characteristics were compared between younger and older patients, and survival analysis was performed for both groups. Prognostic factors affecting overall survival in young patients with EC were identified using Cox regression. A nomogram was created and internal validation was performed using the consistency index, decision curve analysis, receiver operating characteristic curves, and calibration curves. External validation used data from 70 patients with early onset EC. Finally, Kaplan-Meier curves were plotted to compare survival outcomes across the risk subgroups. RESULTS: A total of 1042 young patients and 12,991 older patients were included in this study. Younger patients were divided into training (732) and validation (310) cohorts in a 7:3 ratio. Cox regression analysis identified age, tumorsize, grade, FIGO stage(International Federation of Gynecology and Obstetrics) and surgery as independent risk factors for overall survival, and a nomogram was constructed based on these factors. Internal and external validations demonstrated the good predictive power of the nomogram. In particular, the C-index for the overall survival nomogram was 0.832 [95% confidence interval (0.797-0.844)] in the training cohort and 0.839 (0.810-0.868) in the internal validation cohort. The differences in the Kaplan-Meier curves between the different risk subgroups were statistically significant. CONCLUSIONS: In this study, a nomogram for predicting overall survival of patients with early onset endometrial cancer based on the SEER database was developed to help assess the prognosis of patients and guide clinical treatment.


Assuntos
Neoplasias do Endométrio , Nomogramas , Feminino , Gravidez , Humanos , Neoplasias do Endométrio/terapia , Calibragem , Bases de Dados Factuais , Pacientes , Prognóstico
12.
Lasers Med Sci ; 38(1): 232, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37819407

RESUMO

This study aimed to investigate the effect of Low-Level Laser Therapy (LLLT) on human Periodontal Ligament Cells (hPDLCs) under tension stress. Primary hPDLCs were obtained using the tissue culture method, and P3 cells were utilized for the subsequent experiments. The study comprised four groups: a blank control group (Group B), a laser irradiation group (Group L), a tension stress group (Group T), and a laser + tension stress group (Group LT). Mechanical loading was applied using an in-vitro cell stress loading device at a frequency of 0.5 Hz and deformation of 2% for two hours per day for two days. Laser irradiation at 808 nm GaAlAs laser was administered 1 h after force loading. Cell samples were collected after the experiment. Bone and fiber remodeling factors were analyzed using PCR and Western blot. Flow cytometry was employed to assess the cell cycle, while ROS and Ca2+ levels were measured using a multifunctional enzyme labeling instrument. The results revealed that laser intervention under tension stress inhibited the expression of osteogenic differentiation factors, promoted the expression of osteoclast differentiation factors, and significantly increased the production of collagen factors, MMPs, and TIMPs. The LT group exhibited the most active cell cycle (P < 0.05). LLLT not only enhanced Ca2+ expression in hPDLCs under tension stress, but also stimulated the production of ROS. Overall, our findings demonstrate that LLLT effectively accelerated the proliferation of hPDLCs and the remodeling of periodontal tissue, possibly through the regulation of ROS and Ca2+ levels in hPDLCs.


Assuntos
Osteogênese , Ligamento Periodontal , Humanos , Células Cultivadas , Espécies Reativas de Oxigênio/metabolismo , Lasers , Diferenciação Celular
13.
Int J Mol Sci ; 24(8)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37108405

RESUMO

Bisphenol A (BPA) is widely used to harden plastics and polycarbonates and causes serious toxic effects in multiple organs, including the intestines. Selenium, as an essential nutrient element for humans and animals, exhibits a predominant effect in various physiological processes. Selenium nanoparticles have attracted more and more attention due to their outstanding biological activity and biosafety. We prepared chitosan-coated selenium nanoparticles (SeNPs) and further compared the protective effects, and investigated the underlying mechanism of SeNPs and inorganic selenium (Na2SeO3) on BPA-induced toxicity in porcine intestinal epithelial cells (IPEC-J2). The particle size, zeta potential, and microstructure of SeNPs were detected by using a nano-selenium particle size meter and a transmission electron microscope. IPEC-J2 cells were exposed to BPA alone or simultaneously exposed to BPA and SeNPs or Na2SeO3. The CCK8 assay was performed to screen the optimal concentration of BPA exposure and the optimal concentration of SeNPs and Na2SeO3 treatment. The apoptosis rate was detected by flow cytometry. Real-time PCR and Western blot methods were used to analyze the mRNA and protein expression of factors related to tight junctions, apoptosis, inflammatory responses and endoplasmic reticulum stress. Increased death and morphological damage were observed after BPA exposure, and these increases were attenuated by SeNPs and Na2SeO3 treatment. BPA exposure disturbed the tight junction function involved with decreased expression of tight junction protein Zonula occludens 1 (ZO-1), occludin, and claudin-1 proteins. Proinflammatory response mediated by the transcription factor nuclear factor-k-gene binding (NF-κB), such as elevated levels of interleukin-1ß(IL-1ß), interleukin-6 (IL-6), interferon-γ (IFN-γ), interleukin-17 (IL-17), and tumor necrosis factor-α (TNF-α) expression was induced at 6 and 24 h after BPA exposure. BPA exposure also disturbed the oxidant/antioxidant status and led to oxidative stress. IPEC-J2 cell apoptosis was induced by BPA exposure, as indicated by increased BCL-2-associated X protein (Bax), caspase 3, caspase 8, and caspase 9 expression and decreased B-cell lymphoma-2 (Bcl-2) and Bcl-xl expression. BPA exposure activated the endoplasmic reticulum stress (ERS) mediated by the receptor protein kinase receptor-like endoplasmic reticulum kinase (PERK), Inositol requiring enzyme 1 (IRE1α), and activating transcription factor 6 (ATF6). We found that treatment with SeNPs and Na2SeO3 can alleviate the intestinal damage caused by BPA. SeNPs were superior to Na2SeO3 and counteracted BPA-induced tight junction function injury, proinflammatory response, oxidative stress, apoptosis, and ERS stress. Our findings suggest that SeNPs protect intestinal epithelial cells from BPA-induced damage, partly through inhibiting ER stress activation and subsequently attenuating proinflammatory responses and oxidative stress and suppressing apoptosis, thus enhancing the intestinal epithelial barrier function. Our data indicate that selenium nanoparticles may represent an effective and reliable tool for preventing BPA toxicity in animals and humans.


Assuntos
Nanopartículas , Selênio , Humanos , Animais , Suínos , Selênio/farmacologia , Selênio/metabolismo , Endorribonucleases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Intestinos , Células Epiteliais/metabolismo , Nanopartículas/química , Claudinas/metabolismo , Apoptose
14.
Small ; 18(6): e2105664, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34854562

RESUMO

The sluggish kinetics of sulfur conversion in the cathode and the nonuniform deposition of lithium metal at the anode result in severe capacity decay and poor cycle life for lithium-sulfur (Li-S) batteries. Resolving these deficiencies is the most direct route toward achieving practical cells of this chemistry. Herein, a vertically aligned wood-derived carbon plate decorated with Co4 N nanoparticles host (Co4 N/WCP) is proposed that can serve as a host for both the sulfur cathode and the metallic lithium anode. This Co4 N/WCP electrode host drastically enhances the reaction kinetics in the sulfur cathode and homogenizes the electric field at the anode for the uniform lithium plating. Density functional theory calculations confirm the experimental observations that Co4 N/WCP provides a lower energy barrier for the polysulfide redox reaction in the cathode and a low adsorption energy for lithium deposition at the anode. Employing the Co4 N/WCP host at both electrodes in a S@Co4 N/WCP||Li@Co4 N/WCP full cell delivers a specific capacity of 807.9 mAh g-1 after 500 cycles at a 1 C rate. Additional experiments are performed with high areal sulfur loading of 4 mg cm-2 to demonstrate the viability of this strategy for producing practical Li-S cells.


Assuntos
Carbono , Lítio , Eletrodos , Enxofre , Madeira
15.
Opt Express ; 30(19): 35014-35028, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36242503

RESUMO

Due to many technical difficulties, the study of molecular photoacoustic endoscopic (PAE) imaging in deep tissues is limited. In this work, we have set up a multimodal acoustic-resolution-based PAE (AR-PAE) system to image the rabbit rectum and preliminarily explored the potential of molecular PAE for deep-seated targets in proof-of-concept. We developed an improved back-projection (IBP) algorithm for focused detection over the centimeter-scale imaging depth. We also developed a deep-learning-based algorithm to remove the electrical noise from the step motor to prevent data averaging for reduced scanning time. We injected a dose of indocyanine green (ICG) near the rabbit rectum and compared 2D and 3D photoacoustic/ultrasound (PA/US) images at different wavelengths. We proposed incorporating a small camera to guide the slow PA/US endoscopic scan. Results show that this system has achieved a lateral resolution of about 0.77/0.65 mm for PA/US images with a signal-to-noise ratio (SNR) of 25/38 dB at an imaging depth of 1.4 cm. We found that the rectum wall and the ICG can be well distinguished spectroscopically. Results also show that the PA images at 532 nm have higher signal intensity and reflection artifacts from pelvic tendons and bones than those at longer wavelengths such as 800 nm. The proposed methods and the intuitive findings in this work may guide and promote the development of high-penetration molecular PAE.


Assuntos
Técnicas Fotoacústicas , Acústica , Animais , Endoscopia/métodos , Verde de Indocianina/química , Imagem Molecular , Técnicas Fotoacústicas/métodos , Coelhos
16.
Neural Plast ; 2022: 1478048, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36300173

RESUMO

Background: Transient ischemic attack (TIA) is a known risk factor for stroke. Abnormal alterations in the low-frequency range of the gray matter (GM) of the brain have been studied in patients with TIA. However, whether there are abnormal neural activities in the low-frequency range of the white matter (WM) in patients with TIA remains unknown. The current study applied two resting-state metrics to explore functional abnormalities in the low-frequency range of WM in patients with TIA. Furthermore, a reinforcement learning method was used to investigate whether altered WM function could be a diagnostic indicator of TIA. Methods: We enrolled 48 patients with TIA and 41 age- and sex-matched healthy controls (HCs). Resting-state functional magnetic resonance imaging (rs-fMRI) and clinical/physiological/biochemical data were collected from each participant. We compared the group differences between patients with TIA and HCs in the low-frequency range of WM using two resting-state metrics: amplitude of low-frequency fluctuation (ALFF) and fractional ALFF (fALFF). The altered ALFF and fALFF values were defined as features of the reinforcement learning method involving a Q-learning algorithm. Results: Compared with HCs, patients with TIA showed decreased ALFF in the right cingulate gyrus/right superior longitudinal fasciculus/left superior corona radiata and decreased fALFF in the right cerebral peduncle/right cingulate gyrus/middle cerebellar peduncle. Based on these two rs-fMRI metrics, an optimal Q-learning model was obtained with an accuracy of 82.02%, sensitivity of 85.42%, specificity of 78.05%, precision of 82.00%, and area under the curve (AUC) of 0.87. Conclusion: The present study revealed abnormal WM functional alterations in the low-frequency range in patients with TIA. These results support the role of WM functional neural activity as a potential neuromarker in classifying patients with TIA and offer novel insights into the underlying mechanisms in patients with TIA from the perspective of WM function.


Assuntos
Ataque Isquêmico Transitório , Substância Branca , Humanos , Mapeamento Encefálico/métodos , Ataque Isquêmico Transitório/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem
17.
BMC Cardiovasc Disord ; 20(1): 371, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32795253

RESUMO

BACKGROUND: The association of myocardial bridge (MB) with cardiovascular risk and the possible cardiovascular risk factors remain unclear. This study aimed to explore the clinical characteristics and related factors of coronary stenosis proximal to an MB. METHODS: This was a retrospective study of patients with symptoms of coronary atherosclerotic heart disease admitted between 10/2011 and 12/2014 to the Emergency and Cardiology Department of Bayannur Hospital, who underwent selective coronary angiography (SCAG). The patients were assigned to the non-stenosis and stenosis groups according to whether coronary stenosis was proximal to the MB. RESULTS: Among 244 patients with MB and cardiovascular symptoms, 91 (37.3%) had stenosis proximal to the MB. Compared with the non-stenosis group, there were more males (80.2% vs. 55.6%, P < 0.001) and smokers (including those who had quit smoking) (P < 0.001) in the stenosis group. There were no significant differences in blood lipid-related indexes (TG, TC, HDL-C, LDL-C, and VLDL-C) between the two groups. Multivariable analysis suggested that MB location in the middle distal or distal segment of the left anterior descending artery (LAD) increased the odds of coronary stenosis proximal to the MB (OR = 0.439, 95% CI: 1.57-7.532, P = 0.002), which was then considered an independent factor associated with coronary stenosis proximal to the MB. CONCLUSIONS: In patients diagnosed with an MB by SCAG, only MB located in the middle distal or distal segment of the LAD is independently associated with coronary stenosis proximal to the MB.


Assuntos
Estenose Coronária/etiologia , Ponte Miocárdica/complicações , Idoso , Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ponte Miocárdica/diagnóstico , Estudos Retrospectivos , Medição de Risco , Fatores de Risco
18.
Nano Lett ; 19(10): 7457-7463, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31532687

RESUMO

Perovskite oxides have attracted much attention for enabling the oxygen-evolution reaction (OER) over the past decades. Nevertheless, their poor conductivity is still a barrier hindering their use. Herein, we report a catalyst prototype of Co-based antiperovskite nitrides CuNCo3-xVx (0 ≤ x ≤ 1) to be a highly effective OER electrocatalyst. The synthesized CuNCo3-xVx exhibits greatly enhanced activity and stability toward the OER in alkaline medium. The CuNCo2.4V0.6 shows a mere 235 mV of overpotential to reach 10 mA cm-2, which is comparable to that of Ir/C (232 mV). More importantly, the CuNCo2.4V0.6 is more durable than the conventional Ir/C catalyst. The CuNCo2.4V0.6 catalyst enabled a Zn-air battery to exhibit a cycle life of 143 h with a much higher cell efficiency. The V-substituted CuNCo2.4V0.6 provides a higher content of the desirable Co3+ species in the post-OER catalyst, which ensures a high activity over a long-term operation. With these enhanced effects enabled by the compositional flexibility of CuNCo3-xVx antiperovskite nitride, a feasible strategy for optimizing an electrocatalyst with tunable properties is provided.

19.
Angew Chem Int Ed Engl ; 59(40): 17488-17493, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32578368

RESUMO

A group of newly reported antiperovskite nitrides Cux In1-x NNi3 (0≤x≤1) with tunable composition are employed as electrocatalysts for the hydrogen evolution reaction (HER). Cu0.4 In0.6 NNi3 shows the highest intrinsic performance among all developed catalysts with an overpotential of merely 42 mV at 10 mA cmgeo -2 . Stability tests at a high current density of 100 mA cmgeo -2 show its super-stable performance with only 7 mV increase in overpotential after more than 60 hours of measurement, surpassing commercial Pt/C (increase of 170 mV). By partial substitution, the derived antiperovskite nitride achieves a smaller kinetic barrier of water dissociation compared to the unsubstituted InNNi3 and CuNNi3 , revealed by first-principle calculations. It is found that the partially substituted Cux In1-x NNi3 possesses a thermal neutral and desirable Gibbs free energy of hydrogen for HER, ascribed to the tailoring of the energy of d-band center arose by the A-site (A=Cu or In) substitution and a resulting optimization of adsorbate interactions.

20.
World J Urol ; 37(7): 1441-1447, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30361956

RESUMO

PURPOSE: To compare the perioperative and long-term outcomes of retroperitoneal laparoscopic pyelolithotomy (RLP) and percutaneous nephrolithotomy (PCNL) for the treatment of staghorn calculi. METHODS: From May 2011 to March 2017, eligible patients with staghorn calculi were randomly assigned to two groups: RLP and PCNL. Patients underwent the operations prospectively. Subsequently, a follow-up protocol was performed. Perioperative data related to the efficacy, safety and long-term outcomes (stone recurrence and functional changes in the affected kidney) were comparatively analyzed between the two groups. RESULTS: Overall, 105 patients underwent surgical treatment, including 51 in the RLP group and 54 in the PCNL group. There was no difference in demographics or stone characteristics between the two groups. The single-session stone-free rate (SFR) was higher (88.2% vs. 64.8%), the mean hemoglobin drop was lower (0.4 ± 0.3 vs. 1.7 ± 0.9 g/dL), the rate of postoperative fever was lower (5.9% vs. 20.4%), but operative time was longer (135.7 ± 35.5 vs. 101.9 ± 41.2 min) and the total cost was more expensive (5546 ± 772 vs. 3861 ± 402 USD)in the RLP group than in the PCNL group (all p < 0.05). The mean increase in the split function (8.3 ± 3.1 vs. 4.2 ± 2.4 mL/min) and the rate of improvement of the affected kidney (56.3% vs. 35.3%) were significantly higher in the RLP group than in the PCNL group at 1 year after surgery (both p < 0.05). However, the rate of stone recurrence was similar between the groups at a mean follow-up of 47.3 ± 18.6 months. CONCLUSIONS: PCNL remains the first-line treatment for most cases of staghorn calculi. Nevertheless, in some selected cases with the extrarenal and dilated pelvis, RLP can be considered as an alternative management of staghorn calculi, which was associated with a high single-session SFR, low rates of complications, and better functional preservation of the affected kidney.


Assuntos
Pelve Renal/cirurgia , Laparoscopia/métodos , Nefrolitotomia Percutânea/métodos , Cálculos Coraliformes/cirurgia , Adulto , Idoso , Feminino , Humanos , Cálculos Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Nefrotomia/métodos , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Espaço Retroperitoneal/cirurgia , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA