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1.
Small ; : e2306990, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-38084443

RESUMEN

High-performance electromagnetic wave (EMW) absorbers are essential for addressing electromagnetic pollution and military security. However, challenges remain in realizing cost-effectiveness and modulating absorbing properties. In this study, heterogeneous Co/nanoporous carbon (NPC) nano-islands are prepared by efficient method co-precipitation combined with in situ pyrolysis. The multi-regulation strategy of morphology, graphitization, and defect density is achieved by modulating the pyrolysis temperature. Adjusting the pyrolysis temperature can effectively balance the conductivity and defect density, optimizing the impedance matching and enhancing the attenuation. Furthermore, it facilitates obtaining the appropriate shape and size of Co magnetic nanoparticles (Co-MNPs), triggering strong surface plasmon resonance. This resonance, in turn, bolsters the synergy of dielectric and magnetic loss. The incorporation of porous nanostructures not only optimizes impedance matching and enhances multiple reflections but also improves interfacial polarization. Additionally, the presence of enriched defects and heteroatom doping significantly enhances dipole polarization. Notably, the absorber exhibits an impressive minimum reflection loss (RLmin ) of -73.87 dB and a maximum effective absorption bandwidth (EABmax ) of 6.64 GHz. The combination of efficient fabrication methods, a performance regulation strategy through pyrolysis temperature modulation, and radar cross section (RCS) simulation provides a high-performance EMW absorber and can pave the way for large-scale applications.

2.
J Colloid Interface Sci ; 652(Pt B): 1197-1207, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37657219

RESUMEN

To counter the negative effects of electromagnetic radiation on the immunity of precision instruments, the stealthiness of military equipment, and human health, the preparation of porous multi-component nano-composites is considered an effective strategy to obtain efficient microwave absorption. In this work, the spongy ternary nano-composites (STC) with large specific surface area (SSA) and pore volume obtained by adjusting the calcination temperature, the porous effectively improves the impedance matching. The ternary composition of FeCo/Fe0.45Ni0.55/C, large SSA and pore volume provide abundant specific surface/interface for polarization and magnetization, the continuous conductive network is established, the strong dielectric and magnetic loss achieve a synergistic effect, realizing strong absorption in the low-frequency, greatly reducing the minimum reflection loss (RLmin, -56.37 dB) and broadening the effective absorption bandwidth (EAB, 7.45 GHz). The microwave absorption mechanism has been analyzed in detail and its great potential for practical applications has been verified by RCS signal simulations. This research provides an effective method for fabricating high-performance ternary nano-composite microwave absorbers.

3.
Materials (Basel) ; 16(1)2022 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-36614603

RESUMEN

Metal oxide semiconductor gas sensors are widely used to detect toxic and inflammable gases in industrial production and daily life. The main research hotspot in this field is the synthesis of gas sensing materials. Previous studies have shown that incorporating two or more metal oxides to form a heterojunction interface can exhibit superior gas sensing performance in response and selectivity compared with single phase. This review focuses on mainly the synthesis methods and gas sensing mechanisms of metal oxide heterostructures. A significant number of heterostructures with different morphologies and shapes have been fabricated, which exhibit specific sensing performance toward a specific target gas. Among these synthesis methods, the hydrothermal method is noteworthy due to the fabrication of diverse structures, such as nanorod-like, nanoflower-like, and hollow sphere structures with enhanced sensing properties. In addition, it should be noted that the combination of different synthesis methods is also an efficient way to obtain metal oxide heterostructures with novel morphologies. Despite advanced methods in the metal oxide semiconductors and nanotechnology field, there are still some new issues which deserve further investigation, such as long-term chemical stability of sensing materials, reproducibility of the fabrication process, and selectivity toward homogeneous gases. Moreover, the gas sensing mechanism of metal oxide heterostructures is controversial. It should be clarified so as to further integrate laboratory theory research with practical exploitation.

4.
Vet Parasitol ; 301: 109642, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34971828

RESUMEN

Eimeria necatrix, an apicomplexan protozoa of the genus Eimeria, causes intestinal coccidiosis that can reduce growth performance of poultry and result in high mortality in older chickens. In this report, the whole sporozoite proteins of E.necatrix were studied by two-dimensional electrophoresis (2-DE) and Western blotting using hyper-immune chicken serum containing E.necatrix-specific antibodies. Approximately 680 protein spots for E.necatrix sporozoite were detected by 2-DE with silver staining, where 98 spots were cross-reacted with the E. necatrix-specific immune sera. Out of the 56 spots that were selected for MALDI-TOF-MS/MS analysis, 50 unique proteins were identified using the MASCOT software, 8 proteins were identified as known E.necatrix proteins and the rest were all putative proteins. These proteins have a wide range of known or predicted structures, cellular locations and functions, including proteins in category nuclear location & function, multifunctional- or multifunctional motifs-containing proteins, cellular transport and structure-related proteins, proteins of enzymatic activities, motor proteins-related, cell surface and organelle-related proteins. These new findings will enhance our understandings of parasite immunogenicity and immune evasion mechanisms of E. necatrix and facilitate the discovery phase of highly effective vaccine candidates.


Asunto(s)
Coccidiosis , Eimeria , Enfermedades de las Aves de Corral , Animales , Pollos , Coccidiosis/veterinaria , Esporozoítos , Espectrometría de Masas en Tándem/veterinaria
5.
Materials (Basel) ; 13(18)2020 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-32933214

RESUMEN

Cavitation corrosion resistant coatings are an excellent solution to the cavitation corrosion problem. High entropy alloys provide a new possibility for cavitation resistant coatings due to their excellent comprehensive performance. Laser cladding was employed to synthesize AlCoCrxCuFe (x represents the Cr concentration, x = 0.5, 1.0, 1.5, 2.0) high entropy alloy coatings (HECs) on AISI 304 steel. The phase transformation, microstructure, micro-mechanical properties, and cavitation erosion performance of HECs were studied. Results showed that AlCoCrxCuFe HECs were composed of BCC and FCC duplex phase. The microstructure of HECs showed a typical dendritic structure. The composition segregation of interdendrite structures was observed. Cavitation erosion resistance represented by 20 h volume loss was decreased with the increase in Cr content. AlCoCrxCuFe HECs with the lowest chromium content (AlCoCr0.5CuFe) showed the best cavitation erosion resistance among all samples. The cavitation resistance of AlCoCrxCuFe HECs has good correlation with the mechanical parameter Hn3/Er2 (Hn is nanohardness, Er is elastic modulus) and phase formation parameter δ (δ is atomic radius difference). The surface after 20 h of cavitation erosion testing exposed the dendritic structure of BCC phase, which was caused by the destruction of the interdendrite structure by cavitation impact.

6.
Int J Biol Sci ; 15(1): 12-23, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30662343

RESUMEN

To evaluate the antitumor effect of sinoporphyrin sodium mediated photodynamic therapy (DVDMS-PDT) against human colorectal cancer (CRC) and to investigate the role of autophagy in its effect. Shrunken cells, condensed nuclei and increased levels of cleaved caspase-3 and Bax were observed in DVDMS-PDT treated HCT116 cells, reminiscent of apoptosis. DVDMS-PDT showed better antitumor efficiency in HCT116 cells than Photofrin mediated photodynamic therapy (PF-PDT) both in vitro and in vivo. And DVDMS-PDT caused autophagic characteristics: double membrane autophagosome structures and changes in autophagy-related protein expression (ATG7, P62, Bcl-2 and LC3-Ⅱ). In addition, inhibition of autophagy by chloroquine (CQ) promoted apoptosis, suggesting a possible protective role of autophagy in DVDMS-PDT-treated HCT116 cells, which was proved by flow cytometry and western blotting. The results of xenograft mouse model showed markedly increased apoptosis and significantly reduced tumor size in DVDMS-PDT treated group than Control, and DVDMS-PDT exhibited better antitumor efficiency than PF-PDT. Further, no visible tumor was observed in the CQ+DVDMS-PDT group at the end of the xenograft mouse experiment, which confirmed the hypothesis that autophagy was protective to DVDMS-PDT treated HCT116 cells. Our findings suggest that DVDMS is a promising photosensitizer and the combined use of autophagy inhibitor can remarkably enhance the DVDMS-PDT mediated anti-cancer efficiency in HCT116 cells both in vitro and in vivo.


Asunto(s)
Cloroquina/farmacología , Fotoquimioterapia/métodos , Porfirinas/uso terapéutico , Apoptosis/efectos de los fármacos , Western Blotting , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/terapia , Citometría de Flujo , Células HCT116 , Humanos , Etiquetado Corte-Fin in Situ , Microscopía Electrónica de Transmisión
7.
Cell Physiol Biochem ; 48(5): 1983-1994, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30092594

RESUMEN

BACKGROUND/AIMS: Monitoring the appearance and progression of tumors are important for improving the survival rate of patients with ovarian cancer. This study aims to examine circulating tumor cells (CTCs) in epithelial ovarian cancer (EOC) patients to evaluate their clinical significance in comparison to the existing biomarker CA125. METHODS: Immuomagnetic bead screening, targeting epithelial antigens on ovarian cancer cells, combined with multiplex reverse transcriptase-polymerase chain reaction (Multiplex RT-PCR) was used to detect CTCs in 211 samples of peripheral blood (5 ml) from 109 EOC patients. CTCs and CA125 were measured in serial from 153 blood and 153 serum samples from 51 patients and correlations with treatment were analyzed. Immunohistochemistry was used to detect the expression of tumor-associated proteins in tumor tissues and compared with gene expression in CTCs from patients. RESULTS: CTCs were detected in 90% (98/109) of newly diagnosed patients. In newly diagnosed patients, the number of CTCs was correlated with stage (p=0.034). Patients with stage IA-IB disease had a CTC positive rate of 93% (13/14), much higher than the CA125 positive rate of only 64% (9/14) for the same patients. The numbers of CTCs changed with treatment, and the expression of EpCAM (p=0.003) and HER2 (p=0.035) in CTCs was correlated with resistance to chemotherapy. Expression of EpCAM in CTCs before treatment was also correlated with overall survival (OS) (p=0.041). CONCLUSION: Detection of CTCs allows early diagnose and expression of EpCAM in CTC positive patients predicts prognosis and should be helpful for monitoring treatment.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Células Neoplásicas Circulantes/metabolismo , Neoplasias Ováricas/diagnóstico , Adulto , Anciano , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/genética , Antígeno Ca-125/sangre , Resistencia a Antineoplásicos , Molécula de Adhesión Celular Epitelial/genética , Molécula de Adhesión Celular Epitelial/metabolismo , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/patología , Factor de Transcripción PAX8/metabolismo , Pronóstico , Tasa de Supervivencia , Proteínas WT1/metabolismo
8.
Cell Signal ; 47: 79-87, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29601907

RESUMEN

Cancer stem cell (CSC) theory reveals a new insight into the understanding of tumorigenesis and metastasis. Recently, DNA methylation is suggested to be a potential epigenetic mechanism for maintenance of CSCs. What's more, studies have shown that DNA methyltransferase (DNMT) is essential for CSCs and deletion of DNMT can reduce tumorigenesis by limiting CSC pool. Therefore, targeting the epigenetic modifiers especially DNA methylation offers an optional strategy for treating human cancers. In the present study we found that DNMT inhibitor 5-Aza-2'-deoxycytidine (5-AzaDC) markedly reduced colorectal CSC abundance in vitro and suppressed liver metastatic tumor growth in vivo. And 5-AzaDC inhibited the expression of active ß-catenin and down-regulated the Wnt signaling pathway. The Wnt inhibitors were frequently inactivated by promoter methylation in colorectal cancer; however analysis of TCGA data base showed that only the expression of SFRP1 was significantly reduced in tumors compared to normal tissues. In addition, restoring of SFRP1 expression inhibited the stem cell-like potential of colorectal cancer cells. Our results indicated that inhibition of DNMT blocked the self-renewal of colorectal CSCs and SFRP1 was essential for the maintenance of colorectal CSCs.


Asunto(s)
Metilasas de Modificación del ADN/metabolismo , Decitabina/farmacología , Vía de Señalización Wnt/efectos de los fármacos , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Metilación de ADN/efectos de los fármacos , Metilasas de Modificación del ADN/antagonistas & inhibidores , Decitabina/uso terapéutico , Humanos , Receptores de Hialuranos/metabolismo , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos BALB C , Células Madre Neoplásicas/citología , Células Madre Neoplásicas/metabolismo , Tasa de Supervivencia , Trasplante Heterólogo , beta Catenina/metabolismo
9.
Oncotarget ; 8(47): 82326-82343, 2017 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-29137267

RESUMEN

Tumor-associated macrophages are regarded as tumor-enhancers as they have key roles in the subversion of adaptive immunity and in inflammatory circuits that promote tumor progression. Here, we show that cancer cells can subvert macrophages yielding cells that have gained pro-tumor functions. When macrophages isolated from mice or humans are co-cultured with dead cancer cell line cells, induced to undergo apoptosis to mimic chemotherapy, up-regulation of pro-tumor gene expression was identified. Phagocytosis of apoptotic cancer cells by macrophages resulted in their transformation into tumor stem (initiating)-like cells, as indicated by the expression of epithelial markers (e.g., cytokeratin) and stem cell markers (e.g., Oct4) and their capability to differentiate in vitro and self-renew in serum-free media. Moreover, we identified a subset of monocytes/macrophages cells in the blood of cancer (breast, ovarian and colorectal) patients undergoing chemotherapy that harbor tumor transcripts. Our findings uncover a new role for macrophages in tumor development, where they can be transformed into tumor-like cells, potentially by horizontal gene transfer of tumor-derived genes, thus, by taking advantage of chemotherapy, these transformed macrophages promote tumor metastasis by escaping immune surveillance.

10.
J Diabetes Res ; 2017: 2376893, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29318158

RESUMEN

Diabetic cardiomyopathy (DCM) remains the major cause of death associated with diabetes. Researchers have demonstrated the importance of impaired cardiac insulin signaling in this process. Insulin resistance (IR) is an important predictor of DCM. Previous studies examining the dynamic changes in autophagy during IR have yielded inconsistent results. This study aimed to investigate the dynamic changes in autophagy and apoptosis in the rat H9c2 cardiomyocyte IR model. H9c2 cells were treated with 500 µM palmitic acid (PA) for 24 hours, resulting in the induction of IR. To examine autophagy, monodansylcadaverine staining, GFP-LC3 puncta confocal observation, and Western blot analysis of LC3I-to-LC3II conversion were used. Results of these studies showed that autophagic acid vesicles increased in numbers during the first 24 hours and then decreased by 36 hours after PA treatment. Western blot analysis showed that treatment of H9c2 cells with 500 µM PA for 24 hours decreased the expression of Atg12-Atg5, Atg16L1, Atg3, and PI3Kp85. Annexin V/PI flow cytometry revealed that PA exposure for 24 hours increased the rate of apoptosis. Together, this study demonstrates that PA induces IR in H9c2 cells and that this process is accompanied by excessive activation of autophagy and increases in apoptosis.


Asunto(s)
Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Resistencia a la Insulina , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Ácido Palmítico/efectos adversos , Animales , Línea Celular , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/patología , Miocitos Cardíacos/patología , Ratas , Regulación hacia Arriba/efectos de los fármacos
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