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1.
J Am Chem Soc ; 146(7): 4762-4770, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38324552

RESUMEN

Proton batteries are competitive due to their merits such as high safety, low cost, and fast kinetics. However, it is generally difficult for current studies of proton batteries to combine high capacity and high stability, while the research on proton storage mechanism and redox behavior is still in its infancy. Herein, the polyanionic layered copper oxalate is proposed as the anode for a high-capacity proton battery for the first time. The copper oxalate allows for reversible proton insertion/extraction through the layered space but also achieves high capacity through synchronous redox reactions of Cu2+ and C2O42-. During the discharge process, the bivalent Cu-ion is reduced, whereas the C═O of the oxalate group is partially converted to C-O. This synchronous behavior presents two units of charge transfer, enabling the embedding of two units of protons in the (110) crystal face. As a result, the copper oxalate anode demonstrates a high specific capacity of 226 mAh g-1 and maintains stable operation over 1000 cycles with a retention of 98%. This work offers new insights into the development of dual-redox electrode materials for high-capacity proton batteries.

2.
Sensors (Basel) ; 24(1)2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38203123

RESUMEN

In contrast to outdoor environments, indoor positioning encounters signal propagation disruptions due to the presence of buildings, resulting in reduced accuracy and, at times, the inability to determine a location accurately. This research, leveraging the robust penetrative capabilities of Ultra-Wideband (UWB) signals in non-line-of-sight (NLOS) scenarios, introduces a methodology for refining ranging outcomes through a combination of inertial navigation and environmental adjustments to achieve high-precision spatial positioning. This approach systematically enhances the correction of signal propagation errors through walls. Initially, it digitalizes the spatial setting, preserving the error correction parameters. Subsequently, it employs inertial navigation to estimate spatial coordinates and delineate signal propagation pathways to achieve precise ranging results. It iteratively hones the positioning outcomes for enhanced precision. Empirical findings demonstrate that within NLOS conditions, compared to standalone UWB positioning and IMU/UWB fusion positioning using the ESKF algorithm, this positioning technique significantly enhances planar positioning accuracy while achieving a marginal elevation accuracy improvement, albeit with some residual deviations from actual values. Furthermore, this positioning methodology effectively rectifies results in NOLS settings, paving the way for a novel approach to optimize indoor positioning through UWB technology.

3.
Angew Chem Int Ed Engl ; 62(8): e202215552, 2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36536537

RESUMEN

The corrosion, parasitic reactions, and aggravated dendrite growth severely restrict development of aqueous Zn metal batteries. Here, we report a novel strategy to break the hydrogen bond network between water molecules and construct the Zn(TFSI)2 -sulfolane-H2 O deep eutectic solvents. This strategy cuts off the transfer of protons/hydroxides and inhibits the activity of H2 O, as reflected in a much lower freezing point (<-80 °C), a significantly larger electrochemical stable window (>3 V), and suppressed evaporative water from electrolytes. Stable Zn plating/stripping for over 9600 h was obtained. Based on experimental characterizations and theoretical simulations, it has been proved that sulfolane can effectively regulate solvation shell and simultaneously build the multifunctional Zn-electrolyte interface. Moreover, the multi-layer homemade modular cell and 1.32 Ah pouch cell further confirm its prospect for practical application.

4.
Anal Chem ; 94(2): 847-855, 2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-34927417

RESUMEN

Chemiluminescence (CL) with stable and glowing light emission is vital for the accurate detection of biomarkers. Moreover, the catalyst plays an important role in CL systems. Herein, the trimetallic AuPtCo nanopolyhedrons with peroxidase- and catalase-like catalytic activities are readily synthesized via a one-step reduction method. After reaction with the substrate ABEI and oxidant H2O2, the AuPtCo nanozyme can catalyze the CL emission in a flash type. Interestingly, it has been found that the biofunctionalization of the AuPtCo surface can endow the catalytic interface with a slow-diffusion effect, thereby prolonging the emission of glow-type CL. On this basis, two biofunctionalized AuPtCo nanocomposites, named as AuPtCo@Cys and AuPtCo@Ab, are prepared, achieving sensitive and selective detection of H2O2 and lipoprotein-associated phospholipase A2 (Lp-PLA2), respectively. Further, the proposed glow-type CL assays are successfully applied for the determination of H2O2 and Lp-PLA2 in female vaginal discharge and human serum samples, respectively, which exhibit good correlation with the clinical results. Overall, the trimetallic AuPtCo nanozyme-based glow-type CL analysis has demonstrated as a powerful and robust tool for biomarker analysis, which holds great promise in clinical applications.


Asunto(s)
Luminiscencia , Nanopartículas del Metal , Peroxidasa , Catalasa , Catálisis , Femenino , Humanos , Peróxido de Hidrógeno/análisis , Mediciones Luminiscentes/métodos
5.
Small ; 18(51): e2204348, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36336632

RESUMEN

KVPO4 F is one of the most competitive cathode candidates for potassium-ion batteries (KIBs) because of its high output voltage and energy density. Although the gravimetric energy density of KIBs is intensively discussed in literature, little attention is paid to the volumetric energy density. In view of this, pomegranate-like carbon-coated KVPO4 F microspheres with a high volumetric energy density are designed in this work. The nano-sized primary particles with carbon sheets in KVPO4 F microspheres enable promis rate capability by enhancing the K+ diffusion kinetics, while the micro-sized spheres guarantee the improvement of cycling stability. Owing to the dense hierarchical microspheres, the volumetric energy density of cells is greatly improved compared to bulk materials. This cathode delivers a reversible capacity of 101.5 mA h g-1 at 0.3 C with an average output voltage of 4.0 V and a capacity retention of 85.1% after 200 cycles. The KVPO4 F@C microspheres have a compact density of 2.45 g cm-3 and further offer a high volumetric energy density up to 891.3 Wh L-1 . The overcharge behavior of KVPO4 F in the first three cycles is also revealed. The presented KVPO4 F@C microspheres cathode provides a new sight for developing KIBs with large volumetric energy density.

6.
Ann Clin Microbiol Antimicrob ; 21(1): 9, 2022 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-35232448

RESUMEN

BACKGROUND: Olsenella uli is anaerobic or microaerophilic bacteria, commonly found in oral cavity or gastrointestinal tract, which has not been reported to be associated with lower respiratory tract infection. Herein, we report the first case of Olsenella uli infection in the lung. CASE PRESENTATION: A 70-year-old male farmer with no history of other respiratory tract diseases developed a cough with bloody sputum three times a day without obvious causes or other concomitant symptoms. After a period of treatment with empirical antibiotic, his condition did not improve. The computed tomography (CT) and lung biopsy results indicated bilateral pneumonia, and Olsenella uli was identified by micromorphology, sequence analysis and mass spectrometry analysis recovered from sputum. Ceftazidime, a third generation cephalosporin was used for the treatment, and the patient recovered after 10 days. CONCLUSIONS: Our report suggests a causative role of gingival bacteria in the pathogenesis of pneumonia, thus early diagnosis and prompt antibiotic therapy may play a role in the treatment of Olsenella uli induced pneumonia.


Asunto(s)
Actinobacteria , Actinobacteria/genética , Anciano , Humanos , Pulmón/diagnóstico por imagen , Pulmón/patología , Masculino , Neumonía Bacteriana/diagnóstico , Neumonía Bacteriana/tratamiento farmacológico , ARN Ribosómico 16S
7.
J Clin Lab Anal ; 36(2): e24211, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34967040

RESUMEN

BACKGROUND: Presently, the global spread of COVID-19 is still going on, with more than 0.6 million new cases confirmed per day (as of November 20, 2021). However, since China entered a post-epidemic phase in mid-March 2020, the daily number of new domestic infections in the Chinese mainland has been maintained at almost zero or single digits, which was attributed to a series of effective measures for COVID-19 prevention and control adopted by the Chinese government. Among these measures, SARS-CoV-2 nucleic acid testing holds key role for the timely confirmation and isolation of the infections to prevent further transmission. METHODS: Referring to the national policy requirements, since April 30, 2020, The Affiliated Hospital of Qingdao University has conducted SARS-CoV-2 nucleic acid testing in its PCR laboratory for patients and social workers, as well as for environmental monitoring and employee screening. As of mid-November 2020, the daily amount of single-tube samples for nucleic acid testing rose above 4,000. RESULTS: In this article, a rapid and highly effective approach for SARS-CoV-2 nucleic acid daily testing is presented, allowing five technicians to complete nucleic acid testing in 6,500 single-tube samples in one day with a high level of quality. Using this approach, since the samples entered the PCR laboratory, all testing results were reported in 2.5-3 h with satisfactory quality control and precise reporting criterion as prerequisites. CONCLUSION: This testing approach provides a referable workflow for other testing institutions and is expected to play an important role in COVID-19 prevention and control.


Asunto(s)
COVID-19 , Técnicas de Amplificación de Ácido Nucleico , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/prevención & control , China , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Amplificación de Ácido Nucleico/normas , Técnicas de Amplificación de Ácido Nucleico/estadística & datos numéricos , Control de Calidad , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Factores de Tiempo
8.
Angew Chem Int Ed Engl ; 61(31): e202206717, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35610667

RESUMEN

Zinc-ion batteries (ZIB) present great potential in energy storage due to low cost and high safety. However, the poor stability, dendrite growth, and narrow electrochemical window limit their practical application. Herein, we develop a new eutectic electrolyte consisting of ethylene glycol (EG) and ZnCl2 for dendrite-free and long-lifespan ZIBs. The EG molecules participate in the Zn2+ solvation via coordination and hydrogen-bond interactions. Optimizing the ZnCl2 /EG molar ratio (1 : 4) can strengthen intermolecular interactions to form [ZnCl(EG)]+ and [ZnCl(EG)2 ]+ cations. The dissociation-reduction of these complex cations enables the formation of a Cl-rich organic-inorganic hybrid solid electrolyte interphase film on a Zn anode, realizing highly reversible Zn plating/stripping with long-term stability of ≈3200 h. Furthermore, the polyaniline||Zn cell manifests decent cycling performance with ≈78 % capacity retention after 10 000 cycles, and the assembled pouch cell demonstrates high safety and stable capacity. This work opens an avenue for developing eutectic electrolytes for high-safety and practical ZIBs.

9.
BMC Pregnancy Childbirth ; 21(1): 745, 2021 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-34732157

RESUMEN

BACKGROUND: Seasonal influenza can circulate in parallel with coronavirus disease (COVID-19) in winter. In the context of COVID-19 pandemic, the risk of co-infection and the burden it poses on healthcare system calls for timely influenza vaccination among pregnant women, who are the priority population recommended for vaccination. We aimed to evaluate the acceptance of influenza vaccination and associated factors among pregnant women during COVID-19 pandemic, provide evidence to improve influenza vaccination among pregnant women, help reduce the risk of infection and alleviate the burden of healthcare system for co-infected patients. METHODS: We conducted a multi-center cross-sectional study among pregnant women in China. Sociodemographic characteristics, health status, knowledge on influenza, attitude towards vaccination, and health beliefs were collected. Locally weighted scatterplot smoothing regression analysis was used to evaluate the trends in the acceptance of influenza vaccine. Logistic regression was applied to identify factors associated with vaccination acceptance. RESULTS: The total acceptance rate was 76.5% (95%CI: 74.8-78.1%) among 2568 pregnant women enrolled. Only 8.3% of the participants had a history of seasonal influenza vaccination. In the logistic regression model, factors associated with the acceptance of influenza vaccine were western region, history of influenza vaccination, high knowledge of influenza infection and vaccination, high level of perceived susceptibility, perceived benefit, cues to action and low level of perceived barriers. Among 23.5% of the participants who had vaccine hesitancy, 48.0% of them were worried about side effect, 35.6% of them lacked confidence of vaccine safety. CONCLUSIONS: Our findings highlighted that tailored strategies and publicity for influenza vaccination in the context of COVID-19 pandemic are warranted to reduce pregnant women's concerns, improve their knowledge, expand vaccine uptake and alleviate pressure for healthcare system.


Asunto(s)
COVID-19/epidemiología , Virus de la Influenza A/inmunología , Vacunas contra la Influenza/farmacología , Gripe Humana/prevención & control , Pandemias , Complicaciones Infecciosas del Embarazo/prevención & control , Vacunación/métodos , Adulto , China/epidemiología , Comorbilidad , Estudios Transversales , Femenino , Modelo de Creencias sobre la Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Gripe Humana/epidemiología , Aceptación de la Atención de Salud , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , SARS-CoV-2 , Estaciones del Año , Encuestas y Cuestionarios
10.
Small ; 15(2): e1803572, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30548088

RESUMEN

High-capacity anodes of lithium-ion batteries generally suffer from poor electrical conductivity, large volume variation, and low tap density caused by prepared nanostructures, which make it an obstacle to achieve both high-areal capacity and stable cycling performance for practical applications. Herein, micrometer-sized porous Fe2 N/C bulk is prepared to tackle the aforementioned issues, and thus realize both high-areal capacity and stable cycling performance at high mass loading. The porous structure in Fe2 N/C bulk is beneficial to alleviate the volumetric change. In addition, the N-doped carbon conducting networks with high electrical conductivity provide a fast charge transfer pathway. Meanwhile, the micrometer-sized Fe2 N/C bulk exhibits a higher tap density than that of commercial graphite powder (1.03 g cm-3 ), which facilitates the preparation of thinner electrode at high mass loadings. As a result, a high-areal capacity of above 4.2 mA h cm-2 at 0.45 mA cm-2 is obtained at a high mass loading of 7.0 mg cm-2 for LIBs, which still maintains at 2.59 mA h cm-2 after 200 cycles with a capacity retention of 98.8% at 0.89 mA cm-2 .

11.
Proc Natl Acad Sci U S A ; 112(14): 4411-6, 2015 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-25831546

RESUMEN

Cancer stem cells (CSCs) with enhanced tumorigenicity and chemoresistance are believed to be responsible for treatment failure and tumor relapse in ovarian cancer patients. However, it is still unclear how CSCs survive DNA-damaging agent treatment. Here, we report an elevated expression of DNA polymerase η (Pol η) in ovarian CSCs isolated from both ovarian cancer cell lines and primary tumors, indicating that CSCs may have intrinsically enhanced translesion DNA synthesis (TLS). Down-regulation of Pol η blocked cisplatin-induced CSC enrichment both in vitro and in vivo through the enhancement of cisplatin-induced apoptosis in CSCs, indicating that Pol η-mediated TLS contributes to the survival of CSCs upon cisplatin treatment. Furthermore, our data demonstrated a depletion of miR-93 in ovarian CSCs. Enforced expression of miR-93 in ovarian CSCs reduced Pol η expression and increased their sensitivity to cisplatin. Taken together, our data suggest that ovarian CSCs have intrinsically enhanced Pol η-mediated TLS, allowing CSCs to survive cisplatin treatment, leading to tumor relapse. Targeting Pol η, probably through enhancement of miR-93 expression, might be exploited as a strategy to increase the efficacy of cisplatin treatment.


Asunto(s)
Cisplatino/química , ADN Polimerasa Dirigida por ADN/metabolismo , Neoplasias Ováricas/genética , Animales , Línea Celular Tumoral , Supervivencia Celular , ADN/química , Daño del ADN , Reparación del ADN , ADN Polimerasa Dirigida por ADN/genética , Regulación hacia Abajo , Femenino , Citometría de Flujo , Humanos , Ratones , Ratones Desnudos , MicroARNs/genética , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia , Trasplante de Neoplasias , Células Madre Neoplásicas/citología , Células Madre Neoplásicas/efectos de los fármacos , Neoplasias Ováricas/metabolismo , Recurrencia
13.
Carcinogenesis ; 38(10): 976-985, 2017 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-28981631

RESUMEN

Subunit 2 of DNA damage-binding protein complex (DDB2) is an early sensor of nucleotide excision repair (NER) pathway for eliminating DNA damage induced by UV radiation (UVR) and cisplatin treatments of mammalian cells. DDB2 is modified by ubiquitin and poly(ADP-ribose) (PAR) in response to UVR, and these modifications play a crucial role in regulating NER. Here, using immuno-analysis of irradiated cell extracts, we have identified multiple post-irradiation modifications of DDB2 protein. Interestingly, although the DNA lesions induced by both UVR and cisplatin are corrected by NER, only the UV irradiation, but not the cisplatin treatment, induces any discernable DDB2 modifications. We, for the first time, show that the appearance of UVR-induced DDB2 modifications depend on the binding of DDB2 to the damaged chromatin and the participation of functionally active 26S proteasome. The in vitro and in vivo analysis revealed that SUMO-1 conjugations comprise a significant portion of these UVR-induced DDB2 modifications. Mapping of SUMO-modified sites demonstrated that UVR-induced SUMOylation occurs on Lys-309 residue of DDB2 protein. Mutation of Lys-309 to Arg-309 diminished the DDB2 SUMOylation observable both in vitro and in vivo. Moreover, K309R mutated DDB2 lost its function of recruiting XPC to the DNA damage sites, as well as the ability to repair cyclobutane pyrimidine dimers following cellular UV irradiation. Taken together, our results indicate that DDB2 is modified by SUMOylation upon UV irradiation, and this post-translational modification plays an important role in the initial recognition and processing of UVR-induced DNA damage occurring within the context of chromatin.


Asunto(s)
Reparación del ADN/efectos de la radiación , Proteínas de Unión al ADN/metabolismo , Sumoilación/efectos de la radiación , Cromatina/metabolismo , Cromatina/efectos de la radiación , Cisplatino/farmacología , Reparación del ADN/efectos de los fármacos , Reparación del ADN/fisiología , Proteínas de Unión al ADN/genética , Células HeLa , Humanos , Lisina/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Dímeros de Pirimidina/genética , Dímeros de Pirimidina/metabolismo , Sumoilación/efectos de los fármacos , Rayos Ultravioleta
14.
J Biol Chem ; 291(20): 10847-57, 2016 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-26994140

RESUMEN

The response to UV irradiation is important for a cell to maintain its genetic integrity when challenged by environmental genotoxins. An immediate early response to UV irradiation is the rapid induction of activating transcription factor 3 (ATF3) expression. Although emerging evidence has linked ATF3 to stress pathways regulated by the tumor suppressor p53 and the histone acetyltransferase Tip60, the role of ATF3 in the UV response remains largely unclear. Here, we report that ATF3 mediated dichotomous UV responses. Although UV irradiation enhanced the binding of ATF3 to Tip60, knockdown of ATF3 expression decreased Tip60 stability, thereby impairing Tip60 induction by UV irradiation. In line with the role of Tip60 in mediating UV-induced apoptosis, ATF3 promoted the death of p53-defective cells in response to UV irradiation. However, ATF3 could also activate p53 and promote p53-mediated DNA repair, mainly through altering histone modifications that could facilitate recruitment of DNA repair proteins (such as DDB2) to damaged DNA sites. As a result, ATF3 rather protected the p53 wild-type cells from UV-induced apoptosis. Our results thus indicate that ATF3 regulates cell fates upon UV irradiation in a p53-dependent manner.


Asunto(s)
Factor de Transcripción Activador 3/metabolismo , Apoptosis/efectos de la radiación , Reparación del ADN/efectos de la radiación , Histona Acetiltransferasas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Rayos Ultravioleta/efectos adversos , Factor de Transcripción Activador 3/genética , Apoptosis/genética , Línea Celular Tumoral , Reparación del ADN/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Estabilidad de Enzimas/genética , Estabilidad de Enzimas/efectos de la radiación , Técnicas de Silenciamiento del Gen , Histona Acetiltransferasas/genética , Humanos , Lisina Acetiltransferasa 5 , Proteína p53 Supresora de Tumor/genética
15.
Nucleic Acids Res ; 43(16): 7838-49, 2015 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-26130719

RESUMEN

The expression of DNA damage-binding protein 2 (DDB2) has been linked to the prognosis of ovarian cancer and its underlying transcription regulatory function was proposed to contribute to the favorable treatment outcome. By applying gene microarray analysis, we discovered neural precursor cell expressed, developmentally downregulated 4-Like (NEDD4L) as a previously unidentified downstream gene regulated by DDB2. Mechanistic investigation demonstrated that DDB2 can bind to the promoter region of NEDD4L and recruit enhancer of zeste homolog 2 histone methyltransferase to repress NEDD4L transcription by enhancing histone H3 lysine 27 trimethylation (H3K27me3) at the NEDD4L promoter. Given that NEDD4L plays an important role in constraining transforming growth factor ß signaling by targeting activated Smad2/Smad3 for degradation, we investigated the role of DDB2 in the regulation of TGF-ß signaling in ovarian cancer cells. Our data indicate that DDB2 enhances TGF-ß signal transduction and increases the responsiveness of ovarian cancer cells to TGF-ß-induced growth inhibition. The study has uncovered an unappreciated regulatory mode that hinges on the interaction between DDB2 and NEDD4L in human ovarian cancer cells. The novel mechanism proposes the DDB2-mediated fine-tuning of TGF-ß signaling and its downstream effects that impinge upon tumor growth in ovarian cancers.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Ováricas/genética , Factor de Crecimiento Transformador beta/farmacología , Ubiquitina-Proteína Ligasas/genética , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo , Proteína Potenciadora del Homólogo Zeste 2 , Femenino , Histonas/metabolismo , Humanos , Ubiquitina-Proteína Ligasas Nedd4 , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Complejo Represivo Polycomb 2/metabolismo , Regiones Promotoras Genéticas , Transducción de Señal
16.
Nano Lett ; 16(3): 1523-9, 2016 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-26882441

RESUMEN

Graphene has been widely used to enhance the performance of energy storage devices due to its high conductivity, large surface area, and excellent mechanical flexibility. However, it is still unclear how graphene influences the electrochemical performance and reaction mechanisms of electrode materials. The single-nanowire electrochemical probe is an effective tool to explore the intrinsic mechanisms of the electrochemical reactions in situ. Here, pure MnO2 nanowires, reduced graphene oxide/MnO2 wire-in-scroll nanowires, and porous graphene oxide/MnO2 wire-in-scroll nanowires are employed to investigate the capacitance, ion diffusion coefficient, and charge storage mechanisms in single-nanowire electrochemical devices. The porous graphene oxide/MnO2 wire-in-scroll nanowire delivers an areal capacitance of 104 nF/µm(2), which is 4.0 and 2.8 times as high as those of reduced graphene oxide/MnO2 wire-in-scroll nanowire and MnO2 nanowire, respectively, at a scan rate of 20 mV/s. It is demonstrated that the reduced graphene oxide wrapping around the MnO2 nanowire greatly increases the electronic conductivity of the active materials, but decreases the ion diffusion coefficient because of the shielding effect of graphene. By creating pores in the graphene, the ion diffusion coefficient is recovered without degradation of the electron transport rate, which significantly improves the capacitance. Such single-nanowire electrochemical probes, which can detect electrochemical processes and behavior in situ, can also be fabricated with other active materials for energy storage and other applications in related fields.


Asunto(s)
Técnicas Electroquímicas/instrumentación , Grafito/química , Compuestos de Manganeso/química , Nanocables/química , Óxidos/química , Capacidad Eléctrica , Transporte de Electrón , Diseño de Equipo , Iones/química , Nanocables/ultraestructura , Porosidad
17.
Carcinogenesis ; 37(2): 129-38, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26717995

RESUMEN

Discretely orchestrated chromatin condensation is important for chromosome protection from DNA damage. However, it is still unclear how different chromatin states affect the formation and repair of nucleotide excision repair (NER) substrates, e.g. ultraviolet (UV)-induced cyclobutane pyrimidine dimers (CPD) and the pyrimidine (6-4) pyrimidone photoproducts (6-4PP), as well as cisplatin-induced intrastrand crosslinks (Pt-GG). Here, by using immunofluorescence and chromatin immunoprecipitation assays, we have demonstrated that CPD, which cause minor distortion of DNA double helix, can be detected in both euchromatic and heterochromatic regions, while 6-4PP and Pt-GG, which cause major distortion of DNA helix, can exclusively be detected in euchromatin, indicating that the condensed chromatin environment specifically interferes with the formation of these DNA lesions. Mechanistic investigation revealed that the class III histone deacetylase SIRT1 is responsible for restricting the formation of 6-4PP and Pt-GG in cells, probably by facilitating the maintenance of highly condensed heterochromatin. In addition, we also showed that the repair of CPD in heterochromatin is slower than that in euchromatin, and DNA damage binding protein 2 (DDB2) can promote the removal of CPD from heterochromatic region. In summary, our data provide evidence for differential formation and repair of DNA lesions that are substrates of NER. Both the sensitivity of DNA to damage and the kinetics of repair can be affected by the underlying level of chromatin compaction.


Asunto(s)
Daño del ADN/fisiología , Reparación del ADN/fisiología , Eucromatina/química , Heterocromatina/química , Células Cultivadas , Inmunoprecipitación de Cromatina , Técnica del Anticuerpo Fluorescente , Humanos , Immunoblotting , Dímeros de Pirimidina/metabolismo , Interferencia de ARN
18.
Tumour Biol ; 37(4): 5645-51, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26581907

RESUMEN

The level of microRNA-93 (miR-93) in tumors has been recently reported to be negatively correlated with survival of lung cancer patients. Considering that the most devastating aspect of lung cancer is metastasis, which can be promoted by transforming growth factor-ß (TGF-ß)-induced epithelial-to-mesenchymal transition (EMT), we sought to determine whether miR-93 is involved in this process. Here, we report that a previously unidentified target of miR-93, neural precursor cell expressed developmentally downregulated gene 4-like (NEDD4L), is able to mediate TGF-ß-mediated EMT in lung cancer cells. miR-93 binds directly to the 3'-UTR of the NEDD4L messenger RNA (mRNA), leading to a downregulation of NEDD4L expression at the protein level. We next demonstrated that the downregulation of NEDD4L enhanced, while overexpression of NEDD4L reduced TGF-ß signaling, reflected by increased phosphorylation of SMAD2 in the lung cancer cell line after TGF-ß treatment. Furthermore, overexpression of miR-93 in lung cancer cells promoted TGF-ß-induced EMT through downregulation of NEDD4L. The analysis of publicly available gene expression array datasets indicates that low NEDD4L expression correlates with poor outcomes among patients with lung cancer, further supporting the oncogenic role of miR-93 in lung tumorigenesis and metastasis.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Neoplasias Pulmonares/genética , MicroARNs/genética , Factor de Crecimiento Transformador beta/genética , Ubiquitina-Proteína Ligasas/genética , Carcinogénesis/genética , Línea Celular Tumoral , Complejos de Clasificación Endosomal Requeridos para el Transporte/biosíntesis , Transición Epitelial-Mesenquimal/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/patología , Masculino , MicroARNs/biosíntesis , Ubiquitina-Proteína Ligasas Nedd4 , Metástasis de la Neoplasia , Estadificación de Neoplasias , Proteína Smad2/biosíntesis , Ubiquitina-Proteína Ligasas/biosíntesis
19.
Nano Lett ; 15(1): 738-44, 2015 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-25490409

RESUMEN

Transition metal oxides have attracted much interest for their high energy density in lithium batteries. However, the fast capacity fading and the low power density still limit their practical implementation. In order to overcome these challenges, one-dimensional yolk-shell nanorods have been successfully constructed using manganese oxide as an example through a facile two-step sol-gel coating method. Dopamine and tetraethoxysilane are used as precursors to obtain uniform polymer coating and silica layer followed by converting into carbon shell and hollow space, respectively. As anode material for lithium batteries, the manganese oxide/carbon yolk-shell nanorod electrode has a reversible capacity of 660 mAh/g for initial cycle at 100 mA/g and exhibits excellent cyclability with a capacity of 634 mAh/g after 900 cycles at a current density of 500 mA/g. An enhanced capacity is observed during the long-term cycling process, which may be attributed to the structural integrity, the stability of solid electrolyte interphase layer, and the electrochemical actuation of the yolk-shell nanorod structure. The results demonstrate that the manganese oxide is well utilized with the one-dimensional yolk-shell structure, which represents an efficient way to realize excellent performance for practical applications.

20.
Nano Lett ; 15(3): 2180-5, 2015 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-25654208

RESUMEN

Intercalation of ions in electrode materials has been explored to improve the rate capability in lithium batteries and supercapacitors, due to the enhanced diffusion of Li(+) or electrolyte cations. Here, we describe a synergistic effect between crystal structure and intercalated ion by experimental characterization and ab initio calculations, based on more than 20 nanomaterials: five typical cathode materials together with their alkali metal ion intercalation compounds A-M-O (A = Li, Na, K, Rb; M = V, Mo, Co, Mn, Fe-P). Our focus on nanowires is motivated by general enhancements afforded by nanoscale structures that better sustain lattice distortions associated with charge/discharge cycles. We show that preintercalation of alkali metal ions in V-O and Mo-O yields substantial improvement in the Li ion charge/discharge cycling and rate, compared to A-Co-O, A-Mn-O, and A-Fe-P-O. Diffraction and modeling studies reveal that preintercalation with K and Rb ions yields a more stable interlayer expansion, which prevents destructive collapse of layers and allow Li ions to diffuse more freely. This study demonstrates that appropriate alkali metal ion intercalation in admissible structure can overcome the limitation of cyclability as well as rate capability of cathode materials, besides, the preintercalation strategy provides an effective method to enlarge diffusion channel at the technical level, and more generally, it suggests that the optimized design of stable intercalation compounds could lead to substantial improvements for applications in energy storage.

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