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1.
Drug Resist Updat ; 74: 101085, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38636338

RESUMEN

Enhanced DNA repair is an important mechanism of inherent and acquired resistance to DNA targeted therapies, including poly ADP ribose polymerase (PARP) inhibition. Spleen associated tyrosine kinase (Syk) is a non-receptor tyrosine kinase acknowledged for its regulatory roles in immune cell function, cell adhesion, and vascular development. This study presents evidence indicating that Syk expression in high-grade serous ovarian cancer and triple-negative breast cancers promotes DNA double-strand break resection, homologous recombination (HR), and subsequent therapeutic resistance. Our investigations reveal that Syk is activated by ATM following DNA damage and is recruited to DNA double-strand breaks by NBS1. Once localized to the break site, Syk phosphorylates CtIP, a pivotal mediator of resection and HR, at Thr-847 to promote repair activity, particularly in Syk-expressing cancer cells. Inhibition of Syk or its genetic deletion impedes CtIP Thr-847 phosphorylation and overcomes the resistant phenotype. Collectively, our findings suggest a model wherein Syk fosters therapeutic resistance by promoting DNA resection and HR through a hitherto uncharacterized ATM-Syk-CtIP pathway. Moreover, Syk emerges as a promising tumor-specific target to sensitize Syk-expressing tumors to PARP inhibitors, radiation and other DNA-targeted therapies.


Asunto(s)
Roturas del ADN de Doble Cadena , Resistencia a Antineoplásicos , Recombinación Homóloga , Quinasa Syk , Quinasa Syk/metabolismo , Quinasa Syk/genética , Quinasa Syk/antagonistas & inhibidores , Humanos , Roturas del ADN de Doble Cadena/efectos de los fármacos , Femenino , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Fosforilación , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Reparación del ADN/efectos de los fármacos , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada/antagonistas & inhibidores , Proteínas de la Ataxia Telangiectasia Mutada/genética , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/patología , Animales , Línea Celular Tumoral , Daño del ADN/efectos de los fármacos
2.
Ann Surg Oncol ; 31(1): 421-432, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37925653

RESUMEN

BACKGROUND: We aimed to construct and validate a deep learning (DL) radiomics nomogram using baseline and restage enhanced computed tomography (CT) images and clinical characteristics to predict the response of metastatic lymph nodes to neoadjuvant chemotherapy (NACT) in locally advanced gastric cancer (LAGC). METHODS: We prospectively enrolled 112 patients with LAGC who received NACT from January 2021 to August 2022. After applying the inclusion and exclusion criteria, 98 patients were randomized 7:3 to the training cohort (n = 68) and validation cohort (n = 30). We established and compared three radiomics signatures based on three phases of CT images before and after NACT, namely radiomics-baseline, radiomics-delta, and radiomics-restage. Then, we developed a clinical model, DL model, and a nomogram to predict the response of LAGC after NACT. We evaluated the predictive accuracy and clinical validity of each model using the receiver operating characteristic curve and decision curve analysis, respectively. RESULTS: The radiomics-delta signature was the best predictor among the three radiomics signatures. So, we developed and validated a DL delta radiomics nomogram (DLDRN). In the validation cohort, the DLDRN produced an area under the receiver operating curve of 0.94 (95% confidence interval, 0.82-0.96) and demonstrated adequate differentiation of good response to NACT. Furthermore, the DLDRN significantly outperformed the clinical model and DL model (p < 0.001). The clinical utility of the DLDRN was confirmed through decision curve analysis. CONCLUSIONS: In patients with LAGC, the DLDRN effectively predicted a therapeutic response in metastatic lymph nodes, which could provide valuable information for individualized treatment.


Asunto(s)
Aprendizaje Profundo , Neoplasias Primarias Secundarias , Neoplasias Gástricas , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Terapia Neoadyuvante , Nomogramas , Estudios Retrospectivos , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/tratamiento farmacológico , Tomografía Computarizada por Rayos X
3.
Cancer Cell Int ; 24(1): 93, 2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38431606

RESUMEN

BACKGROUND: Novel therapeutic targets are urgently needed for treating drug-resistant non-small cell lung cancer (NSCLC) and overcoming drug resistance to molecular-targeted therapies. Regulator of G protein signaling 20 (RGS20) is identified as an upregulated factor in many cancers, yet its specific role and the mechanism through which RGS20 functions in NSCLC remain unclear. Our study aimed to identify the role of RGS20 in NSCLC prognosis and delineate associated cellular and molecular pathways. METHODS: Immunohistochemistry and lung cancer tissue microarray were used to verify the expression of RGS20 between NSCLC patients. CCK8 and cell cloning were conducted to determine the proliferation ability of H1299 and Anip973 cells in vitro. Furthermore, Transcriptome sequencing was performed to show enrichment genes and pathways. Immunofluorescence was used to detect the translocation changes of YAP to nucleus. Western blotting demonstrated different expressions of autophagy and the Hippo-PKA signal pathway. In vitro and in vivo experiments verified whether overexpression of RGS20 affect the proliferation and autophagy of NSCLC through regulating the Hippo pathway. RESULTS: The higher RGS20 expression was found to be significantly correlated with a poorer five-year survival rate. Further, RGS20 accelerated cell proliferation by increasing autophagy. Transcriptomic sequencing suggested the involvement of the Hippo signaling pathway in the action of RGS20 in NSCLC. RGS20 activation reduced YAP phosphorylation and facilitated its nuclear translocation. Remarkably, inhibiting Hippo signaling with GA-017 promoted cell proliferation and activated autophagy in RGS20 knock-down cells. However, forskolin, a GPCR activator, increased YAP phosphorylation and reversed the promoting effect of RGS20 in RGS20-overexpressing cells. Lastly, in vivo experiments further confirmed role of RGS20 in aggravating tumorigenicity, as its overexpression increased NSCLC cell proliferation. CONCLUSION: Our findings indicate that RGS20 drives NSCLC cell proliferation by triggering autophagy via the inhibition of PKA-Hippo signaling. These insights support the role of RGS20 as a promising novel molecular marker and a target for future targeted therapies in lung cancer treatment.

4.
Chemistry ; 30(32): e202304003, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38573800

RESUMEN

Proton exchange membrane fuel cells (PEMFCs) and alkaline membrane fuel cells (AEMFCs) have received great attention as energy devices of the next generation. Accelerating oxygen reduction reaction (ORR) kinetics is the key to improve PEMFC and AEMFC performance. Platinum-based catalysts are the most widely used catalysts for the ORR, but their high price and low abundance limit the commercialization of fuel cells. Non-noble metal-nitrogen-carbon (M-N-C) is considered to be the most likely material class to replace Pt-based catalysts, among which Fe-N-C and Co-N-C have been widely studied due to their excellent intrinsic ORR performance and have made great progress in the past decades. With the improvement of synthesis technology and a deeper understanding of the ORR mechanism, some reported Fe-N-C and Co-N-C catalysts have shown excellent ORR activity close to that of commercial Pt/C catalysts. Inspired by the progress, regulation strategies for Fe-N-C and Co-N-C catalysts are summarized in this Review from 5 perspectives: (1) coordinated atoms, (2) environmental heteroatoms and defects, (3) dual-metal active sites, (4) metal-based particle promoters, and (5) curved carbon layers. We also make suggestions on some challenges facing Fe-N-C and Co-N-C research.

5.
Angew Chem Int Ed Engl ; 63(23): e202404766, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38567502

RESUMEN

The single-atom Fe-N-C is a prominent material with exceptional reactivity in areas of sustainable energy and catalysis research. It is challenging to obtain the dense Fe-N4 site without the Fe nanoparticles (NPs) sintering during the Fe-N-C synthesis via high-temperature pyrolysis. Thus, a novel approach is devised for the Fe-N-C synthesis at low temperatures. Taking FeCl2 as Fe source, a hydrogen environment can facilitate oxygen removal and dichlorination processes in the synthesis, efficiently favouring Fe-N4 site formation without Fe NPs clustering at as low as 360 °C. We shed light on the reaction mechanism about hydrogen promoting Fe-N4 formation in the synthesis. By adjusting the temperature and duration, the Fe-N4 structural evolution and site density can be precisely tuned to directly influence the catalytic behaviour of the Fe-N-C material. The FeNC-H2-360 catalyst demonstrates a remarkable Fe dispersion (8.3 wt %) and superior acid ORR activity with a half-wave potential of 0.85 V and a peak power density of 1.21 W cm-2 in fuel cell. This method also generally facilitates the synthesis of various high-performance M-N-C materials (M=Fe, Co, Mn, Ni, Zn, Ru) with elevated single-atom loadings.

6.
J Am Chem Soc ; 145(31): 17220-17231, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37492900

RESUMEN

In electrochemical ethanol oxidation reactions (EOR) catalyzed by Pt metal nanoparticles through a C2 route, the dissociation of the C-C bond in the ethanol molecule can be a limiting factor. Complete EOR processes producing CO2 were always exemplified by the oxidative dehydrogenation of C1 intermediates, a reaction route with less energy utilization efficiency. Here, we report a Pt3Ga/C electrocatalyst with a uniform distribution of Ga over the nanoparticle surface for EOR that produces CO2 at medium potentials (>0.3 V vs SCE) efficiently through direct and sustainable oxidation of C2 intermediate species, i.e., acetaldehyde. We demonstrate the excellent performance of the Pt3Ga-200/C catalyst by using electrochemical in situ Fourier transform infrared reflection spectroscopy (FTIR) and an isotopic labeling method. The atomic interval structure between Pt and Ga makes the surface of nanoparticles nonensembled, avoiding the formation of poisonous *CHx and *CO species via bridge-type adsorption of ethanol molecules. Meanwhile, the electron redistribution from Ga to Pt diminishes the *O/*OH adsorption and CO poisoning on Pt atoms, exposing more available sites for interaction with the C2 intermediates. Furthermore, the dissociation of H2O into *OH is facilitated by the high hydrophilicity of Ga, which is supported by DFT calculations, promoting the deep oxidation of C2 intermediates. Our work represents an extremely rare EOR process that produces CO2 without observing kinetic limitations under medium potential conditions.

7.
Angew Chem Int Ed Engl ; 62(34): e202306166, 2023 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-37309017

RESUMEN

To achieve the Fe-N-C materials with both high activity and durability in proton exchange membrane fuel cells, the attack of free radicals on Fe-N4 sites must be overcome. Herein, we report a strategy to effectively eliminate radicals at the source to mitigate the degradation by anchoring CeO2 nanoparticles as radicals scavengers adjacent (Scaad-CeO2 ) to the Fe-N4 sites. Radicals such as ⋅OH and HO2 ⋅ that form at Fe-N4 sites can be instantaneously eliminated by adjacent CeO2 , which shortens the survival time of radicals and the regional space of their damage. As a result, the CeO2 scavengers in Fe-NC/Scaad-CeO2 achieved ∼80 % elimination of the radicals generated at the Fe-N4 sites. A fuel cell prepared with the Fe-NC/Scaad-CeO2 showed a smaller peak power density decay after 30,000 cycles determined with US DOE PGM-relevant AST, increasing the decay of Fe-NCPhen from 69 % to 28 % decay.

8.
J Transl Med ; 20(1): 558, 2022 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-36463235

RESUMEN

BACKGROUND: Clear cell renal cell cancer (ccRCC) is accompanied by T-cell infiltration. In this study, we sought to determine the difference in T-cell infiltration and the T-cell receptor (TCR) immune repertoire between ccRCC and peritumour tissue. METHODS: T-cell infiltration was examined using immunohistochemistry (IHC) and haematoxylin and eosin (HE) staining. The chi-squared test and Pearson correlation analysis were applied to evaluate the relationship between clinical traits and CD3, CD4, and CD8 expression. Immune repertoire sequencing (IR-Seq) was used to describe the profile of the TCR repertoire. RESULTS: The adjacent tissue showed increased expression of CD3, CD4 and CD8 compared with ccRCC tissue (PCD3 = 0.033; PCD4 = 0.014; PCD8 = 0.004). Indicated CD3+ T-cell density in ccRCC tissue was positively correlated with that in peritumour tissue (P = 0.010, r = 0.514), which implied the T cells in peritumour tissue directly infect the number of cells infiltrating in ccRCC tissue. Moreover, there was a positive correlation between Vimentin expression and indicated positive T-cell marker in ccRCC tissue (PCD3 = 0.035; PCD4 = 0.020; PCD8 = 0.027). Advanced stage revealed less CD4+ T-cell infiltration in ccRCC tissue (PCD4 = 0.023). The results from IR-Seq revealed an obvious increase in VJ and VDJ segment usage, as well as higher complementarity-determining region 3 (CDR3) amino acid (aa) clonotypes in ccRCC. The matched antigen recognized by the TCR of ccRCC may be potential targets. CONCLUSIONS: The current study collectively demonstrates diminished T-cell infiltration and increased CDR3 aa diversity in ccRCC, which may be associated with immunotherapeutic targets for ccRCC patients.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Humanos , Carcinoma de Células Renales/genética , Complejo CD3 , Regiones Determinantes de Complementariedad/genética , Aminoácidos , Neoplasias Renales/genética
9.
Small ; 17(6): e2006698, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33470522

RESUMEN

Tailoring the near-surface composition of Pt-based alloy can optimize the surface chemical properties of a nanocatalyst and further improve the sluggish H2 electrooxidation performance in an alkaline electrolyte. However, the construction of alloy nanomaterials with a precise near-surface composition and smaller particle size still needs to overcome huge obstacles. Herein, ultra-small PtRu3 binary nanoparticles (<2 nm) evenly distributed on porous carbon (PtRu3 /PC), with different near-surface atomic compositions (Pt-increased and Ru-increased), are successfully synthesized. XPS characterizations and electrochemical test confirm the transformation of a near-surface atomic composition after annealing PtRu3 /PC-300 alloy; when annealing in CO atmosphere, forming the Pt-increased near-surface structure (500 °C), while the Ru-increased near-surface structure appears in an Ar heat treatment process (700 °C). Furthermore, three PtRu3 /PC nanocatalysts all weaken the hydrogen binding strength relative to the Pt/PC. Remarkably, the Ru-increased nanocatalyst exhibits up to 38.8-fold and 9.2-fold HOR improvement in mass activity and exchange current density, compared with the Pt/PC counterpart, respectively. CO-stripping voltammetry tests demonstrate the anti-CO poisoning ability of nanocatalysts, in the sequence of Ru-increased ≥ PtRu3 /PC-300 > Pt-increased > Pt/PC. From the perspective of engineering a near-surface structure, this study may open up a new route for the development of high-efficiency electrocatalysts with a strong electronic effect and oxophilic effect.

10.
J Transl Med ; 19(1): 288, 2021 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-34217324

RESUMEN

BACKGROUND: This study aimed to establish and validate an easy-to-operate novel scoring system based on simple and readily available clinical indices for predicting the progression of chronic kidney disease (CKD). METHODS: We retrospectively evaluated 1045 eligible CKD patients from a publicly available database. Factors included in the model were determined by univariate and multiple Cox proportional hazard analyses based on the training set. RESULTS: Independent prognostic factors including etiology, hemoglobin level, creatinine level, proteinuria, and urinary protein/creatinine ratio were determined and contained in the model. The model showed good calibration and discrimination. The area under the curve (AUC) values generated to predict 1-, 2-, and 3-year progression-free survival in the training set were 0.947, 0.931, and 0.939, respectively. In the validation set, the model still revealed excellent calibration and discrimination, and the AUC values generated to predict 1-, 2-, and 3-year progression-free survival were 0.948, 0.933, and 0.915, respectively. In addition, decision curve analysis demonstrated that the model was clinically beneficial. Moreover, to visualize the prediction results, we established a web-based calculator ( https://ncutool.shinyapps.io/CKDprogression/ ). CONCLUSION: An easy-to-operate model based on five relevant factors was developed and validated as a conventional tool to assist doctors with clinical decision-making and personalized treatment.


Asunto(s)
Insuficiencia Renal Crónica , Área Bajo la Curva , Bases de Datos Factuales , Progresión de la Enfermedad , Humanos , Internet , Estudios Retrospectivos
11.
Chemistry ; 27(32): 8337-8343, 2021 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-33847024

RESUMEN

Oxygen defects and hollow structures positively impact pseudocapacitive properties of diffusion/surface-controlled processes, a component of critical importance when building high-performance supercapacitors. Hence, we fabricated hollow nickel/cobalt molybdate rods with O-defects (D-H-NiMoO4 @CoMoO4 ) through a soft-template and partial reduction method, enhancing D-H-NiMoO4 @CoMoO4 's electrochemical performance, yielding a specific capacitance of 1329 F g-1 , and demonstrating excellent durability with 95.8 % capacity retention after 3000 cycles. D-H-NiMoO4 @CoMoO4 was used as the positive electrode to construct an asymmetric supercapacitor, displaying an energy density of up to 34.13 Wh kg-1 and demonstrating good predisposition towards practical applications. This work presents an effective approach to fabricate and use hollow nickel/cobalt molybdate rods with O-defects as pseudocapacitor material for high-performance capacitive energy storage devices.

12.
Pulm Pharmacol Ther ; 70: 102070, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34403779

RESUMEN

Copious evidence reveals that long non-coding RNAs (lncRNAs) exert great regulatory functions in various human cancers. LINC01224 is a novel lncRNA, identified as a cancer regulator of HCC. However, the underlying mechanisms and clinical significance of LINC01224 in other types of cancers need further researches to explore. In this study, we aimed to elucidate the biological role of LINC01224 in NSCLC progression. Presently, LINNC01224 expression was elevated and miR-2467 expression was down-regulated in NSCLC, compared with standard control. Then we described the reciprocal correlation between LINC01224 and miR 2467. Afterward, the dual-luciferase reporter assay, RIP assay and RNA pull-down assay validated the base-pair interaction between LINC01224 and miR-2467. Moreover, our findings demonstrated that the silence of LINC01224 inhibited cell proliferation and invasion in NSCLC and enhanced cisplatin (CDDP) sensitivity in vitro. Besides, rescue assays verified that miR-2467 inhibitor could reverse the effects on cell biological activities and CDDP resistance caused by knockdown of LINC01224. Finally, in vivo experiments implicated that knockdown of LINC01224 could inhibit NSCLC tumor growth. To sum up, LINC01224 can promote tumor progression and CDDP resistance in NSCLC via sponging miR-2467, suggesting a promising therapeutic target for better diagnosis and prognosis of NSCLC patients.


Asunto(s)
Resistencia a Antineoplásicos , Neoplasias Pulmonares , MicroARNs , ARN Largo no Codificante , Carcinoma de Pulmón de Células no Pequeñas , Proliferación Celular , Cisplatino/farmacología , Resistencia a Antineoplásicos/genética , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , MicroARNs/genética , ARN Largo no Codificante/genética
13.
Cancer Cell Int ; 20: 307, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32684844

RESUMEN

BACKGROUND: Although the fact that long non-coding RNA MCM3AP antisense RNA 1 (MCM3AP-AS1) is oncogenic in several cancers is well documented, very few researchers investigate its expression and function in prostate cancer. METHODS: Paired prostate cancer samples were selected, and expressions of MCM3AP-AS1, miR-876-5p and WNT5A were examined by qRT-PCR. MCM3AP-AS1 shRNA was transfected into LNCaP and PC-3 cell lines, and then the proliferative activity and apoptosis of cancer cells were detected by CCK-8 assay, EdU assay and flow cytometry analysis, respectively. qRT-PCR and Western blot were used to analyze the changes of miR-876-5p and WNT5A. Luciferase reporter gene assay was employed to determine the regulatory relationship between miR-876-5p and MCM3AP-AS1, miR-876-5p and WNT5A. RESULTS: MCM3AP-AS1 was significantly up-regulated in cancerous tissues of prostate cancer samples, positively correlated with the expression of WNT5A, while negatively related with miR-876-5p. After transfection of MCM3AP-AS1 shRNA into prostate cancer cells, the proliferative ability of cancer cells was signally inhibited, but the apoptosis of cancer cells was increased. MCM3AP-AS1 shRNA could reduce the expression of WNT5A on both mRNA and protein levels. Besides, MCM3AP-AS1 was identified as a sponge of miR-876-5p. WNT5A was validated as a target gene of miR- 876-5p. CONCLUSION: MCM3AP-AS1 is abnormally up-regulated in prostate cancer tissues and can modulate the proliferation and apoptosis of prostate cancer cells, which has the potential to be the "ceRNA" to regulate the expression of WNT5A by targeting miR-876-5p.

14.
Cancer Cell Int ; 20: 301, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32669977

RESUMEN

BACKGROUND: Researches validate that circular RNAs (circRNAs) are dysregulated in a variety of malignancies and play an important role in regulating the malignant phenotype of tumor cells. Nevertheless, the role of circ_0000527 in retinoblastoma (RB) and its regulatory mechanisms remain largely unknown. METHODS: Real-time PCR (RT-PCR) was used to detect circ_0000527 and miR-646 expression in RB tissues and cells. The LRP6 expression in RB cells was detected by Western blot. The relationship between circ_0000527 expression and the clinicopathological parameters of RB patients was analyzed. Cell proliferation, apoptosis and metastasis were monitored by cell counting kit-8 (CCK-8), flow cytometry, and Transwell assay. The dual-luciferase reporter gene assay and RIP assay were employed to verify the targeting relationship between circ_0000527 and miR-646, miR-646 and LRP6. RESULTS: Circ_0000527 was highly expressed in both RB and RB cell lines, whose high expression level and degree of differentiation were significantly correlated with the increase in cTNM staging level. Overexpression of circ_0000527 contributed to RB cell proliferation, migration, invasion and suppressed cell apoptosis, while knocking down circ_0000527 inhibited the above malignant biological behavior. The underlying mechanism suggested that functioning as a endogenous competitive RNA, circ_0000527 directly targeted miR-646 and positively regulated LRP6 expression. CONCLUSION: Circ_0000527 enhances the proliferation and metastasis of RB cells by modulating the miR-646/LRP6 axis.

15.
Angew Chem Int Ed Engl ; 59(49): 21976-21979, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32860730

RESUMEN

Metal-containing nanoparticles (M-NPs) in metal/nitrogen-doped carbon (M-N-C) catalysts have been considered hostile to the acidic oxygen reduction reaction (ORR). The relation between M-NPs and the active sites of metal coordinated with nitrogen (MNx ) is hard to establish in acid medium owing to the poor stability of M-NPs. Herein, we develop a strategy to successfully construct a new FeCo-N-C catalyst containing highly active M-NPs and MN4 composite sites (M/FeCo-SAs-N-C). Enhanced catalytic activity and stability of M/FeCo-SAs-N-C is shown experimentally. Calculations reveal that there is a strong interaction between M-NPs and FeN4 sites, which can favor ORR by activating the O-O bond, thus facilitating a direct 4 e- process. Those findings firstly shed light on the highly active M-NPs and FeN4 composite sites for catalyzing acid oxygen reduction reaction, and the relevant reaction mechanism is suggested.

16.
Angew Chem Int Ed Engl ; 59(50): 22397-22402, 2020 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-32893447

RESUMEN

Driven by the persisting poor understanding of the sluggish kinetics of the hydrogen evolution reaction (HER) on Pt in alkaline media, a direct correlation of the interfacial water structure and activity is still yet to be established. Herein, using Pt and Pt-Ni nanoparticles we first demonstrate a strong dependence of the proton donor structure on the HER activity and pH. The structure of the first layer changes from the proton acceptors to the donors with increasing pH. In the base, the reactivity of the interfacial water varied its structure, and the activation energies of water dissociation increased in the sequence: the dangling O-H bonds < the trihedrally coordinated water < the tetrahedrally coordinated water. Moreover, optimizing the adsorption of H and OH intermediates can re-orientate the interfacial water molecules with their H atoms pointing towards the electrode surface, thereby enhancing the kinetics of HER. Our results clarified the dynamic role of the water structure at the electrode-electrolyte interface during HER and the design of highly efficient HER catalysts.

19.
Acc Chem Res ; 49(11): 2569-2577, 2016 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-27739662

RESUMEN

The performance of nanomaterials in electrochemical energy conversion (fuel cells) and storage (secondary batteries) strongly depends on the nature of their surfaces. Designing the structure of electrode materials is the key approach to achieving better performance. Metal or metal oxide nanocrystals (NCs) with high-energy surfaces and open surface structures have attained significant attention in the past decade since such features possess intrinsically exceptional properties. However, they are thermodynamically metastable, resulting in a huge challenge in their shape-controlled synthesis. The tuning of material structure, design, and performance on the nanoscale for electrochemical energy conversion and storage has attracted extended attention over the past few years. In this Account, recent progress made in shape-controlled synthesis of nanomaterials with high-energy surfaces and open surface structures using both electrochemical methods and surfactant-based wet chemical route are reviewed. In fuel cells, the most important catalytic materials are Pt and Pd and their NCs with high-energy surfaces of convex or concave morphology. These exhibit remarkable activity toward electrooxidation of small organic molecules, such as formic acid, methanol, and ethanol and so on. In practical applications, the successful synthesis of Pt NCs with high-energy surfaces of small sizes (sub-10 nm) realized a superior high mass activity. The electrocatalytic performances have been further boosted by synergetic effects in bimetallic systems, either through surface decoration using foreign metal atoms or by alloying in which the high-index facet structure is preserved and the electronic structure of the NCs is altered. The intrinsic relationship of high electrocatalytic performance dependent on open structure and high-energy surface is also valid for (metal) oxide nanomaterials used in Li ion batteries (LIB). It is essential for the anode nanomaterials to have optimized structures to keep them more stable during the charge/discharge processes for reducing damaging volume expansion via intercalation and subsequent reduced battery lifetime. In the case of cathodes, tuning the surface structure of nanomaterials should be one of the most beneficial strategies to enhance the capacity and rate performance. In addition, metal oxides with unique defective structure of high catalytic activity and carbon materials of porous structure for facilitating fast Li+ diffusion paths and efficiently trapping polysulfide are most important approached and employed in Li-O2 battery and Li-S battery, respectively. In summary, significant progress has already been made in the electrocatalytic field, and likely emerging techniques based on NCs enclosed with high-energy surfaces and high-index facets could provide a promising platform to investigate the surface structure-catalytic functionality at nanoscale, thus shedding light on the rational design of practical catalysts with high activity, selectivity, and durability for energy conversion and storage.

20.
Histopathology ; 71(1): 53-62, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28199742

RESUMEN

AIMS: Anaplastic lymphoma kinase (ALK)-rearranged renal cell carcinoma (RCC) is a rare subtype of RCC reported in recent years, with eight cases so far. The aims of the present study were to screen ALK-rearranged cases from a large cohort of RCCs in China to determine the frequency of ALK rearrangement and investigate the clinicopathological features and outcomes. METHODS AND RESULTS: Tissues from a total of 477 RCC patients in China were embedded into tissue microarrays for immunostaining. Fluorescence in-situ hybridization (FISH) and fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR) were applied to identify and confirm the rearrangement of ALK, and to identify the genes fused with ALK. ALK expression was identified in two of 477 RCCs. By FISH analysis, the two tumours showed either a 1R1G1F or a 2R2G signal pattern, indicating rearrangement involving ALK. Fluorescence quantitative RT-PCR detected the TPM3-ALK fusion and EML4-ALK fusion transcripts in the two tumours, respectively. Follow-up data were analyzed for the two cases and eight other ALK-rearranged RCCs reported in the literature. Two patients died from RCCs, on the 16th month and 48th month after surgery, respectively. The 5-year cancer-specific survival rate of patients with the 10 ALK-rearranged RCCs was lower than that of patients with International Society of Urological Pathology (ISUP) G1, G2 and G3 clear cell RCC (CCRCC) and papillary RCC (PRCC), but higher than that of patients with G4 CCRCC and PRCC. CONCLUSIONS: ALK-rearranged RCC is a rare subtype of adult RCC and is associated with distinct histological features and a poor prognosis. Identification of ALK-rearranged RCC has important clinical significance, because patients might benefit from ALK inhibitor therapy as used in lung adenocarcinoma.


Asunto(s)
Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Neoplasias Renales/genética , Neoplasias Renales/patología , Proteínas Tirosina Quinasas Receptoras/genética , Quinasa de Linfoma Anaplásico , Pueblo Asiatico/genética , Femenino , Reordenamiento Génico , Humanos , Masculino , Persona de Mediana Edad
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