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1.
Nano Lett ; 24(34): 10642-10649, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39158134

RESUMO

CO poisoning in Pt-based anode catalysts significantly hampers the proton exchange membrane fuel cell (PEMFC) performance. Despite great advances in CO-tolerant catalysts, their effectiveness is often limited to fundamental three-electrode systems, which is inadequate for practical PEMFC applications. Herein, we present a straightforward thermal oxidation strategy for constructing a Ru oxide blocking layer on commercial PtRu/C through a one-step Ru-segregation-and-oxidation process. The resulting 0.7 nm thick Ru oxide layer effectively inhibits CO adsorption while maintaining hydrogen oxidation activity. PtRu@RuO2/C demonstrates exceptional CO tolerance, enduring 1% CO in rotating disk electrode tests, an ∼10-fold improvement compared to that of PtRu/C. Crucially, it retains high HOR activity and CO tolerance in PEMFC, with negligible polarization curve loss in the presence of 100 ppm CO. Notably, 85% HOR activity is retained after a 4 h stability test. This enhancement contributes to the Ru oxide layer decelerating CO adsorption kinetics, rather than promoting CO oxidation via the classic bifunctional mechanism.

2.
Biol Proced Online ; 25(1): 25, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37726652

RESUMO

BACKGROUND: Exosomes, a special subtype of extracellular vesicles derived from human cells, serve as vital mediators of intercellular communication by transporting diverse bioactive cargos, including proteins and enzymes. However, the underlying mechanisms governing exosome secretion and regulation remain poorly understood. In this study, we employed a dual-reporter system consisting of bioluminescent Gaussia luciferase and fluorescent proteins to investigate the dynamics and regulation of exosome secretion in cultured human cells. RESULTS: Our results demonstrated that the engineered dual-reporters effectively monitored both exosome-mediated and ER-Golgi-mediated secretory pathways in a specific and quantitative manner. Notably, we observed distinct characteristics of exosome-mediated protein secretion, including significantly lower capacity and different dynamics compared to the ER-Golgi pathway. This phenomenon was observed in human kidney 293T cells and liver HepG2 cells, emphasizing the conserved nature of exosome-mediated secretion across cell types. Furthermore, we investigated the impact of brefeldin A (BFA), an inhibitor of ER-to-Golgi membrane trafficking, on protein secretion. Interestingly, BFA inhibited protein secretion via the ER-Golgi pathway while stimulating exosome-mediated protein secretion under same experimental conditions. CONCLUSIONS: Collectively, our study highlights the utility of the dual-reporter system for real-time monitoring and quantitative analysis of protein secretion through conventional ER-Golgi and unconventional exosome pathways. Moreover, our findings unveil distinct features of exosome-mediated protein secretion, shedding light on its differential capacity, dynamics, and regulatory mechanisms compared to ER-Golgi-mediated proteins in human cells.

3.
J Am Chem Soc ; 144(21): 9292-9301, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35593455

RESUMO

CO poisoning of Pt-group metal catalysts is a long-standing problem, particularly for hydrogen oxidation reaction in proton exchange membrane fuel cells. Here, we report a catalyst of Ru oxide-coated Ru supported on TiO2 (Ru@RuO2/TiO2), which can tolerate 1-3% CO, enhanced by about 2 orders of magnitude over the classic PtRu/C catalyst, for hydrogen electrooxidation in a rotating disk electrode test. This catalyst can work stably in 1% CO/H2 for 50 h. About 20% of active sites can survive even in a pure CO environment. The high CO tolerance is not via a traditional bifunctional mechanism, i.e., oxide promoting CO oxidation, but rather via hydrous metal oxide shell blocking CO adsorption. An ab initio molecular dynamics (AIMD) simulation indicates that water confined in grain boundaries of the Ru oxide layer and Ru surface can suppress the diffusion and adsorption of CO. This oxide blocking layer approach opens a promising avenue for the design of high CO-tolerant electrocatalysts for fuel cells.

4.
Biochem Biophys Res Commun ; 512(1): 29-33, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30853185

RESUMO

Gastric cancer (GC) is still a major aggressive malignancy worldwide. While the importance of circular RNAs (circRNAs) involved in carcinogenesis has gradually been acknowledged, their role in human cancers is not largely understood, including in GC. Here, we focused on hsa_circ_0001368 in GC, a novel circRNA that has not been previously reported. In the current study, we found a broad downregulation of hsa_circ_0001368 in GC tissues and cells, which correlates with a worse prognosis in GC patients. Functional experiments suggested that the knockdown of hsa_circ_0001368 promoted cell viability and motility by cell proliferation and invasion assays. In addition, the knockdown of hsa_circ_0001368 led to accelerated tumor growth in vivo. Mechanically, we demonstrated that hsa_circ_0001368 served as a competing endogenous RNA (ceRNA) to sponge miR-6506-5p. Subsequently, FOXO3 may act as the functional target of miR-6506-5p, and the knockdown of hsa_circ_0001368 decreased the expression of the tumor-suppressive gene FOXO3. Taken together, our study revealed that hsa_circ_0001368 plays a tumor-suppression role in GC via the miR-6506-5p/FOXO3 axis and may serve as a potential target for GC therapy.


Assuntos
Proteína Forkhead Box O3/genética , MicroRNAs/genética , RNA Circular/genética , Neoplasias Gástricas/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Regulação para Baixo , Proteína Forkhead Box O3/metabolismo , Técnicas de Silenciamento de Genes , Genes Supressores de Tumor , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/metabolismo , Invasividade Neoplásica/genética , Prognóstico , RNA Circular/antagonistas & inibidores , RNA Circular/metabolismo , Neoplasias Gástricas/metabolismo
5.
J Clin Lab Anal ; 33(3): e22726, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30461077

RESUMO

BACKGROUND: Emerging evidence indicates that dysregulation of circular RNAs (circRNAs) is implicated in the development of malignancies. However, the diagnostic value and functional role of circRNAs in gastric cancer (GC) remain largely elusive. METHODS: Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to detect the expression of hsa_circ_0000467 in tissues, cell lines, and plasma. A receiver operating characteristic (ROC) curve was constructed to estimate the diagnostic value of hsa_circ_0000467. The association between the expression level of hsa_circ_0000467 and the clinicopathological features was analyzed. Moreover, cell functional assays were performed. RESULTS: Hsa_circ_0000467 was significantly upregulated in GC tissue compared to adjacent nontumor tissue (n = 51, P < 0.05). Similar results were detected in the HGC-27, MGC-803, AGS, NUGC-3, GES-1 cell lines (n = 15, P < 0.001), and in the plasma samples from GC patients (n = 20, P < 0.05). The area under the ROC curve of hsa_circ_0000467 was 0.790, which is superior to commonly used biomarkers including CEA and CA-724. We found that the expression levels of hsa_circ_0000467 in the same patient were significantly lower after surgery (n = 20, P < 0.05). Moreover, the hsa_circ_0000467 expression level is closely associated with TNM stage. Additionally, Cox multivariate analysis showed that hsa_circ_0000467 is a novel independent prognostic factor. Furthermore, in vitro experiments demonstrated that knockdown of hsa_circ_0000467 markedly inhibited the proliferation, migration, and invasion of GC cells. Moreover, hsa_circ_0000467 silencing increased tumor apoptosis in vitro. CONCLUSION: Hsa_circ_0000467 can act as a novel noninvasive biomarker for the diagnosis and prognosis of GC and may be a potential therapeutic target for GC.


Assuntos
Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , RNA/análise , RNA/genética , Neoplasias Gástricas , Apoptose , Biomarcadores Tumorais/metabolismo , Estudos de Casos e Controles , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Humanos , Pessoa de Meia-Idade , Especificidade de Órgãos , Prognóstico , RNA/metabolismo , RNA Circular , Curva ROC , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia
6.
Front Plant Sci ; 15: 1440234, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39391774

RESUMO

UAV-based plant protection represents an efficient, energy-saving agricultural technology with significant potential to enhance tea production. However, the complex terrain of hilly and mountainous tea fields, coupled with the limited endurance of UAVs, presents substantial challenges for efficient route planning. This study introduces a novel methodological framework for UAV-based precision plant protection across multiple tea fields, addressing the difficulties in planning the shortest routes and optimal flights for UAVs constrained by their endurance. The framework employs a hyperbolic genetic annealing algorithm (ACHAGA) to optimize UAV plant protection routes with the objectives of minimizing flight distance, reducing the number of turns, and enhancing route stability. The method involves two primary steps: cluster partitioning and sortie allocation for multiple tea fields based on UAV range capabilities, followed by refining the UAV's flight path using a combination of hyperbolic genetic and simulated annealing algorithms with an adaptive temperature control mechanism. Simulation experiments and UAV route validation tests confirm the effectiveness of ACHAGA. The algorithm consistently identified optimal solutions within an average of 40 iterations, demonstrating robust global search capabilities and stability. It achieved an average reduction of 45.75 iterations and 1811.93 meters in the optimal route, with lower variation coefficients and extreme deviations across repeated simulations. ACHAGA significantly outperforms these algorithms, GA, GA-ACO, AFSA and BSO, which are also heuristic search strategies, in the multi-tea field route scheduling problem, reducing the optimal routes by 4904.82 m, 926.07 m, 3803.96 m and 800.11 m, respectively. Field tests revealed that ACHAGA reduced actual flight routes by 791.9 meters and 359.6 meters compared to manual and brainstorming-based planning methods, respectively. Additionally, the algorithm reduced flight scheduling distance and the number of turns by 11 compared to manual planning. This study provides a theoretical and technical foundation for managing large-scale tea plantations in challenging landscapes and serves as a reference for UAV precision operation planning in complex environments.

7.
Pharmaceutics ; 16(6)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38931944

RESUMO

Exosomes, nanoscale vesicles derived from human cells, offer great promise for targeted drug delivery. However, their inherent diversity and genetic modifications present challenges in terms of ensuring quality in clinical use. To explore solutions, we employed advanced gene fusion and transfection techniques in human 293T cells to generate two distinct sets of genetically engineered samples. We used dual-omics analysis, combining transcriptomics and proteomics, to comprehensively assess exosome quality by comparing with controls. Transcriptomic profiling showed increased levels of engineering scaffolds in the modified groups, confirming the success of genetic manipulation. Through transcriptomic analysis, we identified 15 RNA species, including 2008 miRNAs and 13,897 mRNAs, loaded onto exosomes, with no significant differences in miRNA or mRNA levels between the control and engineered exosomes. Proteomics analysis identified changes introduced through genetic engineering and over 1330 endogenous exosome-associated proteins, indicating the complex nature of the samples. Further pathway analysis showed enrichment in a small subset of cellular signaling pathways, aiding in our understanding of the potential biological impacts on recipient cells. Detection of over 100 cow proteins highlighted the effectiveness of LC-MS for identifying potential contaminants. Our findings establish a dual-omics framework for the quality control of engineered exosome products, facilitating their clinical translation and therapeutic applications in nanomedicine.

8.
Front Plant Sci ; 14: 1177114, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37346117

RESUMO

To address the problem of accurate recognition and localization of multiple clusters of green persimmons with similar color to the background under natural environment, this study proposes a multi-cluster green persimmon identification method based on improved Faster RCNN was proposed by using the self-built green persimmon dataset. The feature extractor DetNet is used as the backbone feature extraction network, and the model detection attention is focused on the target object itself by adding the weighted ECA channel attention mechanism to the three effective feature layers in the backbone, and the detection accuracy of the algorithm is improved. By maximizing the pooling of the lower layer features with the added attention mechanism, the high and low dimensions and magnitudes are made the same. The processed feature layers are combined with multi-scale features using a serial layer-hopping connection structure to enhance the robustness of feature information, effectively copes with the problem of target detection of objects with obscured near scenery in complex environments and accelerates the detection speed through feature complementarity between different feature layers. In this study, the K-means clustering algorithm is used to group and anchor the bounding boxes so that they converge to the actual bounding boxes, The average mean accuracy (mAP) of the improved Faster RCNN model reaches 98.4%, which was 11.8% higher than that of traditional Faster RCNN model, which also increases the accuracy of object detection during regression prediction. and the average detection time of a single image is improved by 0.54s. The algorithm is significantly improved in terms of accuracy and speed, which provides a basis for green fruit growth state monitoring and intelligent yield estimation in real scenarios.

9.
Waste Manag ; 165: 189-198, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37149393

RESUMO

A large amount of hazardous spent lithium-ion batteries (LIBs) is produced every year. Recovery of valuable metals from spent LIBs is significant to achieve environmental protection and alleviate resource shortages. In this study, a green and facile process for recovery of valuable metals from spent LIBs by waste copperas was proposed. The effects of heat treatment parameters on recovery efficiency of valuable metals and the redox mechanism were studied systematically through phase transformation behavior and valence transition. At low temperature (≤460 °C), copperas reacted with lithium on the outer layer of LIBs preferentially, but the reduction of transition metals was limited. As the temperature rose to 460-700 °C, the extraction efficiency of valuable metals was greatly enhanced due to the generation of SO2, and the gas-solid reaction proceeded much fast than the solid-solid reaction. In the final stage (≥700 °C), the main reactions were the thermal decomposition of soluble sulfates and the combination of decomposed oxides with Fe2O3 to form insoluble spinel. Under the optimum roasting conditions, i.e., at a copperas/LIBs mass ratio of 4.5, and a roasting temperature of 650 °C and roasting time of 120 min, the leaching efficiencies of Li, Ni, Co and Mn were 99.94%, 99.2%, 99.5% and 99.65%, respectively. The results showed that valuable metals can be selectively and efficiently extracted from the complex cathode materials by water leaching. This study used waste copperas as an aid to recover metals and provided an alternative technical route for green recycling of spent LIBs.


Assuntos
Lítio , Metais , Fontes de Energia Elétrica , Reciclagem , Temperatura
10.
Front Plant Sci ; 13: 998962, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36186015

RESUMO

The complex environments and weak infrastructure constructions of hilly mountainous areas complicate the effective path planning for plant protection operations. Therefore, with the aim of improving the current status of complicated tea plant protections in hills and slopes, an unmanned aerial vehicle (UAV) multi-tea field plant protection route planning algorithm is developed in this paper and integrated with a full-coverage spraying route method for a single region. By optimizing the crossover and mutation operators of the genetic algorithm (GA), the crossover and mutation probabilities are automatically adjusted with the individual fitness and a dynamic genetic algorithm (DGA) is proposed. The iteration period and reinforcement concepts are then introduced in the pheromone update rule of the ant colony optimization (ACO) to improve the convergence accuracy and global optimization capability, and an ant colony binary iteration optimization (ACBIO) is proposed. Serial fusion is subsequently employed on the two algorithms to optimize the route planning for multi-regional operations. Simulation tests reveal that the dynamic genetic algorithm with ant colony binary iterative optimization (DGA-ACBIO) proposed in this study shortens the optimal flight range by 715.8 m, 428.3 m, 589 m, and 287.6 m compared to the dynamic genetic algorithm, ant colony binary iterative algorithm, artificial fish swarm algorithm (AFSA) and particle swarm optimization (PSO), respectively, for multiple tea field scheduling route planning. Moreover, the search time is reduced by more than half compared to other bionic algorithms. The proposed algorithm maintains advantages in performance and stability when solving standard traveling salesman problems with more complex objectives, as well as the planning accuracy and search speed. In this paper, the research on the planning algorithm of plant protection route for multi-tea field scheduling helps to shorten the inter-regional scheduling range and thus reduces the cost of plant protection.

11.
J Colloid Interface Sci ; 609: 139-148, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34894548

RESUMO

Glucose oxidation reaction (GOR) plays a significant role in glucose fuel cells anode and glucose sensors. Therefore, optimizing the GOR catalyst nanostructure is auxiliary to their efficient operation. In this study, we present a cascade-assembled strategy to prepare CuO nanobundles (CuO-NB) with high-density and homogenous grainboundaries (GBs). The essence of activity in GOR that depended on GBs are thoroughly investigated. The increased glucose diffusion coefficient of CuO-NB means that GBs has a faster glucose mass transfer, which is attributed to the terraces in GBs dislocation surface. Furthermore, the accumulation of electrons on GBs makes the glucose adsorption increased and the free energy of dehydrogenation step decreased, leading to a lower glucose oxidation barrier. Therefore, CuO-NB is appropriate for non-invasive glucose detection and glucose fuel cells. This study sheds new light on the GBs effect in GOR and paves the way for developing high-efficiency electrocatalysts.


Assuntos
Cobre , Glucose , Catálise , Eletrodos
12.
ACS Appl Mater Interfaces ; 14(27): 30724-30734, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35766357

RESUMO

The oxygen reduction reaction (ORR) activity of the Fe/N/Carbon catalysts derived from the pyrolysis of zeolitic-imidazolate-framework-8 (ZIF-8) has been still lower than that of commercial Pt-based catalysts utilized in the proton exchange membrane fuel cells (PEMFCs) due to low density of accessible active sites. In this study, an efficient carbon-supporting strategy is developed to enhance the ORR efficiency of the ZIF-derived Fe/N/Carbon catalysts by increasing the accessible active site density. The enhancement lies in (i) improving the accessibility of active sites via converting dodecahedral particles to graphene-like layered materials and (ii) enhancing the density of FeNx active sites via suppressing the formation of nanoparticles as well as providing extra spaces to host active sites. The optimized and efficient Fe/N/Carbon catalyst shows a half-wave potential (E1/2) of 0.834 V versus reversible hydrogen electrode in acidic media and produces a peak power density of 0.66 W cm-2 in an air-fed PEMFC at 2 bar backpressure, outperforming most previously reported Pt-free ORR catalysts. Finally, the general applicability of the carbon-supporting strategy is confirmed using five different commercial carbon blacks. This work provides an effective route to derive Fe/N/Carbon catalysts exhibiting a higher power density in PEMFCs.

13.
J Phys Chem Lett ; 12(32): 7797-7803, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34375530

RESUMO

The identification of the generation pathway of •OH radical during the oxygen reduction reaction (ORR) is critical because it determines which strategy should be adopted to minimize these corrosive species. In this way, researchers can develop a more stable Fe/N/C ORR catalyst or a catalyst layer in the proton exchange membrane fuel cells (PEMFCs). To date, this critical problem has still been unresolved. Herein, the generation of the •OH radical during the acidic ORR was mimicked by using two known pathways, that is, the Fenton (and Fenton-like) and the electrochemical reduction of H2O2(H2O2-ECR) process. The latter was determined as the main generation pathway of •OH radical below 30 °C. As the temperature surpassed 30 °C, the H2O2-ECR process began to lose its dominance because of the appearance of a third so-far unknown generation pathway. This work lays a basis for future development of radical elimination strategies to stabilize a Fe/N/C ORR catalyst or a catalyst layer in PEMFCs.

14.
World J Gastroenterol ; 25(2): 258-268, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30670914

RESUMO

BACKGROUND: Anastomotic leakage (AL) is a severe complication associated with high morbidity and mortality after radical gastrectomy (RG) for gastric cancer (GC). We hypothesized that a novel abdominal negative pressure lavage-drainage system (ANPLDS) can effectively reduce the failure-to-rescue (FTR) and the risk of reoperation, and it is a feasible management for AL. AIM: To report our institution's experience with a novel ANPLDS for AL after RG for GC. METHODS: The study enrolled 4173 patients who underwent R0 resection for GC at our institution between June 2009 and December 2016. ANPLDS was routinely used for patients with AL after January 2014. Characterization of patients who underwent R0 resection was compared between different study periods. AL rates and postoperative outcome among patients with AL were compared before and after the ANPLDS therapy. We used multivariate analyses to evaluate clinicopathological and perioperative factors for associations with AL and FTR after AL. RESULTS: AL occurred in 83 (83/4173, 2%) patients, leading to 7 deaths. The mean time of occurrence of AL was 5.6 days. The AL rate was similar before (2009-2013, period 1) and after (2014-2016, period 2) the implementation of the ANPLDS therapy (1.7% vs 2.3%, P = 0.121). Age and malnourishment were independently associated with AL. The FTR rate and abdominal bleeding rate after AL occurred were respectively 8.4% and 9.6% for the entire period; however, compared with period 1, this significantly decreased during period 2 (16.2% vs 2.2%, P = 0.041; 18.9% vs 2.2%, P = 0.020, respectively). Moreover, the reoperation rate was also reduced in period 2, although this result was not statistically significant (13.5% vs 2.2%, P = 0.084). Additionally, only ANPLDS therapy was an independent protective factor for FTR after AL (P = 0.04). CONCLUSION: Our experience demonstrates that ANPLDS is a feasible management for AL after RG for GC.


Assuntos
Fístula Anastomótica/terapia , Drenagem/métodos , Falha da Terapia de Resgate/estatística & dados numéricos , Gastrectomia/efeitos adversos , Neoplasias Gástricas/cirurgia , Irrigação Terapêutica/métodos , Fatores Etários , Idoso , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Fístula Anastomótica/mortalidade , Estudos de Viabilidade , Feminino , Gastrectomia/métodos , Humanos , Laparoscopia/efeitos adversos , Laparoscopia/métodos , Masculino , Desnutrição/complicações , Desnutrição/epidemiologia , Pessoa de Meia-Idade , Reoperação/estatística & dados numéricos , Estudos Retrospectivos
15.
Dis Markers ; 2019: 3863458, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31565098

RESUMO

OBJECTIVE: Circular RNAs (circRNAs) have been reported to be widely involved in pathological processes of various cancers. However, little is known about their diagnostic values in early gastric cancer (EGC). This study is aimed at exploring whether circulating circRNAs in plasma could act as biomarkers for EGC diagnosis. MATERIALS AND METHODS: Mass spectrometry (MS) was performed to identify the proteins that at significantly aberrantly levels in gastric cancer (GC) tissues. The target circRNA was identified by bioinformatics analysis. A receiver operating characteristic (ROC) curve was generated to evaluate the diagnostic utility. RESULTS: MS revealed that the ribosomal protein L6 (RPL6) expression was significantly downregulated only in EGC tissues vs. nontumorous tissues; this was validated by western blotting (n = 30, p = 0.0094). Bioinformatics analysis predicted that there is a hsa_circ_0006848/hsa_miR-329-5p/RPL6 axis in GC progression. The hsa_circ_0006848 expression was significantly downregulated in EGC tissues (vs. nontumorous tissues, n = 30, p = 0.0073) and plasma samples from EGC patients (vs. paired healthy volunteers, n = 30, p = 0.0089). In addition, the hsa_circ_0006848 plasma level in postoperative patients was significantly higher than that of preoperative patients (n = 30, p = 0.047). Furthermore, the decreased hsa_circ_0006848 expression in plasma was negatively correlated with poor differentiation (p = 0.037) and tumor size (p = 0.046). The area under the ROC curve (AUC) of hsa_circ_0006848 in plasma was 0.733, suggesting a good diagnostic value. The plasma hsa_circ_0006848 level combined with the carcinoembryonic antigen (CEA), carbohydrate-associated antigen 19-9 (CA19-9), and carbohydrate-associated antigen 72-4 (CA72-4) level increased the AUC to 0.825. CONCLUSION: Our results indicated that plasma hsa_circ_0006848 may be a novel noninvasive biomarker in EGC diagnosis.


Assuntos
Biomarcadores Tumorais/sangue , Ácidos Nucleicos Livres/sangue , RNA Circular/sangue , Proteínas Ribossômicas/genética , Neoplasias Gástricas/sangue , Biomarcadores Tumorais/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Ribossômicas/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia
16.
Oncol Rep ; 41(2): 779-788, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30431123

RESUMO

Several previous studies have demonstrated that cyclin­dependent kinase (CDK)­5 expression serves an important role in promoting the development of malignant tumours. We have previously reported that CDK5 suppresses gastric tumourigenesis. The aim of the present study was to investigate the mechanistic basis of CDK5. The results of immunoprecipitation and western blot analysis demonstrated that CDK5 could interact with serine/threonine­protein phosphatase 2A (PP2A). The use of an inhibitor of PP2A in CDK5­overexpressing gastric cancer (GC) cell lines antagonized CDK5­mediated suppression in GC cells. Further analysis revealed that PP2A expression was downregulated in GC and patients with low levels of PP2A had worse survival outcomes than those with high levels of PP2A (P=0.035). Therefore, the present study provided a novel mechanism for CDK5­mediated tumour suppression, suggesting that CDK5 may be an attractive target for future therapeutic strategies for treating GC. In addition, low levels of PP2A may indicate a tendency for poor prognosis in patients with GC.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Proteína Fosfatase 2/metabolismo , Neoplasias Gástricas/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Ácido Okadáico/farmacologia , Prognóstico , Ligação Proteica , Proteína Fosfatase 2/antagonistas & inibidores , Estômago/patologia , Neoplasias Gástricas/mortalidade
17.
ChemSusChem ; 11(5): 881-887, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29446547

RESUMO

Cu is a unique catalyst for CO2 electroreduction, since it can catalyze CO2 reduction to a series of hydrocarbons, alcohols, and carboxylic acids. Nevertheless, such Cu catalysts suffer from poor selectivity. High pressure of CO2 is considered to facilitate the activity and selectivity of CO2 reduction. Herein, a new strategy is presented for CO2 reduction with improved C2 H4 selectivity on a Cu catalyst by using CO2 capture materials as the support at ambient pressure. N-doped carbon (Nx C) was synthesized through high-temperature carbonization of melamine and l-lysine. We observed that the CO2 uptake capacity of Nx C depends on both the microporous area and the content of pyridinic N species, which can be controlled by the carbonization temperature (600-800 °C). The as-prepared CuO/Nx C catalysts exhibit a considerably higher C2 H4 faradaic efficiency (36 %) than CuO supported on XC-72 carbon black (19 %), or unsupported CuO (20 %). Moreover, there is a good linear relationship between the C2 H4 faradaic efficiency and CO2 uptake capacity of the supports for CuO. The local high CO2 concentration near Cu catalysts, created by CO2 capture materials, was proposed to increase the coverage of CO intermediate, which is favorable for the coupling of two CO units in the formation of C2 H4 . This study demonstrates that pairing Cu catalysts with CO2 capture supports is a promising approach for designing highly effective CO2 reduction electrocatalysts.


Assuntos
Dióxido de Carbono/química , Cobre/química , Técnicas Eletroquímicas/métodos , Álcoois/síntese química , Ácidos Carboxílicos/síntese química , Catálise , Etilenos/química , Hidrocarbonetos/síntese química , Oxirredução , Temperatura
18.
J Exp Clin Cancer Res ; 37(1): 59, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29540196

RESUMO

BACKGROUND: CDK5RAP3 was initially isolated as a binding protein of the CDK5 activator p35. Although CDK5RAP3 has been shown to negatively regulate the Wnt/ß-catenin signaling pathway in gastric cancer by repressing GSK-3ß phosphorylation, its in-depth mechanism has not been determined. METHODS: Following CDK5RAP3 overexpression or knock down, CDK5RAP3 signaling pathways were investigated in gastric cancer cells by Western Blotting. Cell growth, invasion and migration were also evaluated in gastric cancer cell lines. We analyzed CDK5RAP3, AKT, p-AKT (Ser473), GSK-3ß and p-GSK-3ß (Ser9) expression in gastric tumor samples and adjacent non-tumor tissues from 295 patients using immunohistochemistry and Western Blotting. The prognostic significance of CDK5RAP3 and p-AKT (Ser473) was confirmed by a Log-rank test. RESULTS: Our study demonstrated that the expression of p-AKT (Ser473) and p-GSK-3ß (Ser9) was negatively correlated with CDK5RAP3 in stable gastric cancer cell lines. CDK5RAP3 repressed AKT phosphorylation, which promoted GSK-3ß phosphorylation, thereby suppressing ß-catenin protein expression and, consequently, gastric cancer. The protein level of CDK5RAP3 was markedly decreased in most gastric tumor tissues compared with adjacent non-tumor tissues, and the levels of p-AKT (Ser473) and p-GSK-3ß (Ser9) were also negatively correlated with those of CDK5RAP3. The prognostic value of CDK5RAP3 for overall survival was found to be dependent on AKT phosphorylation. CONCLUSION: Our results demonstrated that CDK5RAP3 negatively regulates the Wnt/ß-catenin signaling pathway by repressing AKT phosphorylation, which leads to better survival of patients with gastric cancer.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo , Via de Sinalização Wnt , Idoso , Idoso de 80 Anos ou mais , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Feminino , Inativação Gênica , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Fosforilação , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Análise Serial de Tecidos , Carga Tumoral , Proteínas Supressoras de Tumor , beta Catenina/genética , beta Catenina/metabolismo
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