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1.
Environ Sci Technol ; 57(39): 14558-14568, 2023 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-37728882

RESUMEN

Due to the extremely high bond energy of N≡N (∼941 kJ/mol), the traditional Haber-Bosch process of ammonia synthesis is known as an energy-intensive and high CO2-emission industry. In this paper, a cascade N2 reduction process with dielectric barrier discharge (DBD) plasma oxidation and electrocatalytic reduction as an alternative route is first proposed. N2 is oxidized to be reactive nitrogen species (RNS) by nonthermal plasma, which would then be absorbed by KOH solution and electroreduced to NH4+. It is found that the production of NOx is a function of discharge length, discharge power, and gas flow rate. Afterward, the cobalt catalyst is used in the process of electrocatalytic reduction of ammonia, which shows high selectivity (Faradic efficiency (FE) above 90%) and high yield of ammonia (45.45 mg/h). Finally, the cascade plasma oxidation and electrocatalytic reduction for ammonia synthesis is performed. Also, the performance of the reaction system is evaluated. It is worth mentioning that a stable and sustainable ammonia production efficiency of 16.21 mg/h is achieved, and 22.16% of NOx obtained by air activation is converted into NH4+. This work provides a demonstration for further industrial application of ammonia production with DBD plasma oxidation and electrocatalytic reduction techniques.


Asunto(s)
Amoníaco , Plasma , Oxidación-Reducción , Aire , Óxido Nítrico
2.
Anal Chem ; 93(18): 7102-7109, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33908770

RESUMEN

Effective acquirement of highly pure circulating tumor cells (CTCs) is very important for CTC-related research. However, it is a great challenge since abundant white blood cells (WBCs) are always co-collected with CTCs because of nonspecific bonding or low depletion rate of WBCs in various CTC isolation platforms. Herein, we designed a three-dimensional (3D) conductive scaffold microchip for highly effective capture and electrochemical release of CTCs with high purity. The conductive 3D scaffold was prepared by dense immobilization of gold nanotubes (Au NTs) on porous polydimethylsiloxane and was functionalized with a CTC-specific biomolecule facilitated by a Au-S bond before embedding into a microfluidic device. The spatially distributed 3D macroporous structure compelled cells to change migration from linear to chaotic and the densely covered Au NTs enhanced the topographic interaction between cells and the substrate, thus synergistically improving the CTC capture efficiency. The Au NT-coated 3D scaffold had good electrical conductivity and the Au-S bond was breakable by voltage exposure so that captured CTCs could be specifically released by electrochemical stimulation while nonspecifically bonded WBCs were not responsive to this process, facilitating recovery of CTCs with high purity. The 3D conductive scaffold microchip was successfully applied to obtain highly pure CTCs from cancer patients' blood, benefiting the downstream analysis of CTCs.


Asunto(s)
Células Neoplásicas Circulantes , Recuento de Células , Línea Celular Tumoral , Separación Celular , Conductividad Eléctrica , Humanos , Dispositivos Laboratorio en un Chip , Análisis por Micromatrices
3.
Diagnostics (Basel) ; 13(15)2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37568923

RESUMEN

BACKGROUND: This study aimed to investigate the natural growth history of peripheral small-cell lung cancer (SCLC) using CT imaging. METHODS: A retrospective study was conducted on 27 patients with peripheral SCLC who underwent at least two CT scans. Two methods were used: Method 1 involved direct measurement of nodule dimensions using a calliper, while Method 2 involved tumour lesion segmentation and voxel volume calculation using the "py-radiomics" package in Python. Agreement between the two methods was assessed using the intraclass correlation coefficient (ICC). Volume doubling time (VDT) and growth rate (GR) were used as evaluation indices for SCLC growth, and growth distribution based on GR and volume measurements were depicted. We collected potential factors related to imaging VDT and performed a differential analysis. Patients were classified into slow-growing and fast-growing groups based on a VDT cut-off point of 60 days, and univariate analysis was used to identify factors influencing VDT. RESULTS: Median VDT calculated by the two methods were 61 days and 71 days, respectively, with strong agreement. All patients had continuously growing tumours, and none had tumours that decreased in size or remained unchanged. Eight patients showed possible growth patterns, with six possibly exhibiting exponential growth and two possibly showing Gompertzian growth. Tumours deeper in the lung grew faster than those adjacent to the pleura. CONCLUSIONS: Peripheral SCLC tumours grow rapidly and continuously without periods of nongrowth or regression. Tumours located deeper in the lung tend to grow faster, but further research is needed to confirm this finding.

4.
Br J Ophthalmol ; 107(4): 525-533, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-34750100

RESUMEN

BACKGROUND/AIMS: To determine whether a combination of baseline and change in spectral domain-optical coherence tomography (SD-OCT)-based biomarkers can predict visual outcomes in eyes with diabetic macular oedema (DMO) treated with antivascular endothelial growth factors (VEGF) injections. METHODS: This is a retrospective cohort study conducted in Hong Kong, China. 196 eyes with centre-involving DMO, who received anti-VEGF injections between 1 January 2011 and 30 June 2018 were recruited. Medical records of the participants were retrieved retrospectively, visual acuity (VA) at baseline, 6, 12 and 24 months and SD-OCT before initiation and after completion of anti-VEGF treatment were obtained. The SD-OCT images were evaluated for the morphology of DMO, vitreomacular status, presence of disorganisation of retinal inner layers (DRIL), sizes of intraretinal cysts, visibility of external limiting membrane (ELM), ellipsoid zone (EZ) and cone outer segment tip (COST) and the presence of hyper-reflective foci in retina or the choroid. RESULTS: The presence of baseline DRIL, hyper-reflective foci in retina and disruption of ELM/EZ and COST were associated with worse baseline and subsequent VA up to 24 months after treatment. Improvement in DRIL (p=0.048), ELM/EZ (p=0.001) and COST (p=0.002) disruption after treatment was associated with greater improvement in VA at 12 months. Eyes with cystoid macular oedema (p=0.003, OR=8.18) and serous retinal detachment (p=0.011, OR=4.84) morphology were more likely to achieve at least 20% reduction in central subfield thickness. CONCLUSION AND RELEVANCE: Baseline SD-OCT biomarkers and their subsequent change predict VA and improvement in vision in eyes with DMO treated with anti-VEGF injections. We proposed an SD-OCT-based system that can be readily used in real-life eye clinics to improve decision making in the management of DMO.


Asunto(s)
Diabetes Mellitus , Retinopatía Diabética , Edema Macular , Humanos , Biomarcadores , Retinopatía Diabética/diagnóstico , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/complicaciones , Angiografía con Fluoresceína/métodos , Inyecciones Intravítreas , Edema Macular/diagnóstico , Edema Macular/tratamiento farmacológico , Retina , Estudios Retrospectivos , Tomografía de Coherencia Óptica/métodos , Factor A de Crecimiento Endotelial Vascular/inmunología
5.
Aging (Albany NY) ; 12(14): 14285-14299, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32669478

RESUMEN

Emerging evidence has shown activation of the complement component C5 to C5a in cancer tissues and C5aR expression in breast cancer cells relates to the tumor development and poor prognosis, suggesting the involvement of complement C5a/C5aR pathway in the breast cancer pathogenesis. In this study, we found that as compared to the non-tumoral tissues, both C5aR and MAPK/p38 showed an elevated expression, but p21/p-p21 showed lower expression, in the tumoral tissues of breast cancer patients. Mice deficient in C5aR or mice treated with the C5aR antagonist exhibited attenuation of breast cancer growth and reduction in the p38/p-p38 expression, but increase in p21/p-p21 expression, in the tumor tissues. Pre-treatment of the breast cancer cells with recombinant C5a resulted in reduced p21 expression, and MAPK/p38 inhibitors prevented C5a-induced reduction in p21 expression, suggesting the involvement of the MAPK/p38 signaling pathway in the C5a/C5aR-mediated suppression of p21/p-p21 expression. These results provide evidence that breast cancer development may rely on C5a/C5aR interaction, for which MAPK/p38 pathway participate in down-regulating the p21 expression. Inhibition of C5a/C5aR pathway is expected to be helpful for the treatment of patients with breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , Receptor de Anafilatoxina C5a/genética , Transducción de Señal/genética , Quinasas p21 Activadas , Proteínas Quinasas p38 Activadas por Mitógenos , Adulto , Animales , Neoplasias de la Mama/patología , Línea Celular Tumoral , Senescencia Celular , Complemento C5a , Femenino , Humanos , Sistema de Señalización de MAP Quinasas , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Persona de Mediana Edad , Proteínas Quinasas Activadas por Mitógenos/genética , Receptor de Anafilatoxina C5a/antagonistas & inhibidores , Proteínas Recombinantes/farmacología
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