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1.
RSC Adv ; 14(28): 19707-19717, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38903670

RESUMO

In recent decades, environmental protection and energy issues have gained significant attention, and the development of efficient, environmentally friendly catalysts has become especially crucial for the advancement of photocatalytic technology. This study employs the sintering method to produce biochar. A hybrid photocatalyst for the degradation of RHB under visible light was prepared by loading varying proportions of biochar onto g-C3N4 using ultrasonic technology. Among them, 2% CGCD (2% biochar/g-C3N4) achieved a degradation rate of 91.3% for RHB after 30 minutes of visible light exposure, which was more than 25% higher than GCD (g-C3N4), and exhibited a higher photocurrent intensity and lower impedance value. The enhancement in photocatalytic activity is primarily attributed to the increased utilization efficiency of visible light and the electron transfer channel effect from a minor amount of biochar, effectively reducing the recombination of photo-generated charge carriers on the g-C3N4 surface, thereby significantly improving photocatalytic activity. The degradation of RHB is synergistically mediated by O2 -, h+ (photo-generated holes), and ˙OH. The free radical capture experiment indicates that O2 - and ˙OH are the primary active components, followed by h+.

2.
RSC Adv ; 14(25): 17498-17506, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38818363

RESUMO

Nowadays, the widespread concern over controlling CO2 emissions and mitigating the adverse effects of greenhouse gases on global climate has attracted significant attention. In this study, g-C3N4 was synthesized by thermopolymerizing urea. Subsequently, ZIF-8 was combined with g-C3N4 using an in situ deposition method, resulting in the fabrication of ZIF-8/g-C3N4 composite photocatalysts at various molar ratios. Effective incorporation of ZIF-8 into g-C3N4 suppressed the recombination of photogenerated electrons and holes, thereby enhancing CO2 capture capacity and preserving light absorption capabilities. The ZIF-8/g-C3N4 composite demonstrates excellent photocatalytic performance for CO2 reduction, where the optimized material exhibited a CO2 adsorption capacity 1.52 times that of pure g-C3N4 and increased the conversion of CO2 to CH4 by more than sevenfold. This study harnesses the superior CO2 adsorption properties of metal-organic frameworks to develop more efficient photocatalysts, enhancing CO2 conversion efficacy and offering insights for developing efficient photocatalysts that utilize CO2.

3.
JMIR Public Health Surveill ; 10: e47428, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38648087

RESUMO

BACKGROUND: Depression is often accompanied by changes in behavior, including dietary behaviors. The relationship between dietary behaviors and depression has been widely studied, yet previous research has relied on self-reported data which is subject to recall bias. Electronic device-based behavioral monitoring offers the potential for objective, real-time data collection of a large amount of continuous, long-term behavior data in naturalistic settings. OBJECTIVE: The study aims to characterize digital dietary behaviors in depression, and to determine whether these behaviors could be used to detect depression. METHODS: A total of 3310 students (2222 healthy controls [HCs], 916 with mild depression, and 172 with moderate-severe depression) were recruited for the study of their dietary behaviors via electronic records over a 1-month period, and depression severity was assessed in the middle of the month. The differences in dietary behaviors across the HCs, mild depression, and moderate-severe depression were determined by ANCOVA (analyses of covariance) with age, gender, BMI, and educational level as covariates. Multivariate logistic regression analyses were used to examine the association between dietary behaviors and depression severity. Support vector machine analysis was used to determine whether changes in dietary behaviors could detect mild and moderate-severe depression. RESULTS: The study found that individuals with moderate-severe depression had more irregular eating patterns, more fluctuated feeding times, spent more money on dinner, less diverse food choices, as well as eating breakfast less frequently, and preferred to eat only lunch and dinner, compared with HCs. Moderate-severe depression was found to be negatively associated with the daily 3 regular meals pattern (breakfast-lunch-dinner pattern; OR 0.467, 95% CI 0.239-0.912), and mild depression was positively associated with daily lunch and dinner pattern (OR 1.460, 95% CI 1.016-2.100). These changes in digital dietary behaviors were able to detect mild and moderate-severe depression (accuracy=0.53, precision=0.60), with better accuracy for detecting moderate-severe depression (accuracy=0.67, precision=0.64). CONCLUSIONS: This is the first study to develop a profile of changes in digital dietary behaviors in individuals with depression using real-world behavioral monitoring. The results suggest that digital markers may be a promising approach for detecting depression.


Assuntos
Depressão , Comportamento Alimentar , Humanos , Feminino , Masculino , Adulto , Depressão/epidemiologia , Depressão/psicologia , Adulto Jovem , Comportamento Alimentar/psicologia , Técnicas de Observação do Comportamento/métodos , Técnicas de Observação do Comportamento/estatística & dados numéricos , Adolescente
4.
Disaster Med Public Health Prep ; 18: e19, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329113

RESUMO

OBJECTIVE: The goal of this study is to explore the risk factors associated with self-contamination points during personal protective equipment (PPE) donning and doffing among health care workers (HCWs). METHODS: In total, 116 HCWs were randomly sampled and trained to don and doff the whole PPE set. We smeared the whole PPE set with the fluorescent powder. After each participant finished PPE doffing, the whole body was irradiated with ultraviolet light in order to detect contamination points and record the position and quantity. Sociodemographic characteristics and previous infection prevention control (IPC) training experience, among others, were collected by using electronic questionnaires. Poisson regression was used in identifying risk factors that are associated with the number of contamination points, and the relative risk (RR) and its 95% confidence interval (CI) were calculated. RESULTS: About 78.5% of participants were contaminated. Ever training experience (RR = 0.37; 0.26, 0.52), clinical departments (RR = 0.67; 0.49, 0.93), body mass index (BMI) (RR = 1.09; 1.01, 1.18), and shoulder width (RR = 1.07; 1.01, 1.13) were associated with the number of contamination points. CONCLUSIONS: Previous IPC training experience, department types, BMI, and shoulder width were associated with self-contamination points after the PPE was removed.


Assuntos
Controle de Infecções , Equipamento de Proteção Individual , Humanos , Pessoal de Saúde/educação , Fatores de Risco
5.
Eur J Pharmacol ; 967: 176365, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38316247

RESUMO

Glycyrrhizic acid (GA), one of the major active components derived from licorice root, exerts liver-protecting activity. Its molecular mechanisms of action, however, remain not completely understood. The angiotensin (Ang) converting enzyme (ACE) 2/Ang-(1-7)/Mas axis, regulated by ACE2 through converting Ang II into Ang-(1-7) to activate Mas receptor, counteracts the pro-inflammatory and pro-steatotic effects of the ACE/Ang II/Ang II receptor type 1 (AT1) axis. Here, it was found that pretreatment with GA suppressed LPS/D-galactosamine-induced serum hyperactivities of alanine aminotransferase and aspartate aminotransferase, hepatomegaly, pathological changes, and over-accumulation of triglycerides and fatty droplets in the liver of mice. GA also diminished LPS/free fatty acid-induced inflammation and steatosis in cultured hepatocytes. Mechanistically, GA restored hepatic protein hypoexpression of ACE2 and Mas receptor, and the decrease in hepatic Ang-(1-7) content. Hepatic overexpression of angiotensin II and AT1 was also suppressed. However, GA did not alter hepatic protein expression of renin and ACE. In addition, GA inhibited hepatic protein over-phosphorylation of the p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, extracellular signal-regulated kinase, and nuclear factor κB at Ser536. Hepatic overexpression of tumor necrosis factor α, interleukin 6, interleukin 1ß, sterol regulatory element-binding protein 1c, and fatty acid synthase was also inhibited. GA-elicited recovery of ACE2 and Mas protein hypoexpression was further confirmed in the hepatocyte. Thus, the present results demonstrate that GA restores the downregulated hepatic ACE2-mediated anti-inflammatory and anti-steatotic signaling in the amelioration of steatohepatitis. We suggest that GA may protect the liver from injury by regulating the hepatic ACE2-mediated signaling.


Assuntos
Enzima de Conversão de Angiotensina 2 , Fígado Gorduroso , Camundongos , Animais , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/uso terapêutico , Lipopolissacarídeos , Peptidil Dipeptidase A/metabolismo , Fragmentos de Peptídeos/farmacologia , Angiotensina II , Angiotensina I/metabolismo , Receptores Acoplados a Proteínas G/metabolismo
6.
Int J Antimicrob Agents ; 61(5): 106783, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36921808

RESUMO

BACKGROUND: Linezolid is a broad-spectrum antimicrobial with limited use due to toxicity. This study aimed to evaluate linezolid toxicity in a large multicentre cohort. Secondary objectives were to identify factors contributing to toxicity, including the impact of therapeutic drug monitoring (TDM). METHODS: Patients administered linezolid between January 2017 and December 2019 were retrospectively reviewed. Data were collected on patient characteristics, linezolid therapy and outcomes. Descriptive statistics were performed on all patients, and statistical comparisons were undertaken between those who did and did not experience linezolid toxicity. A multivariable logistic regression model was constructed to identify any covariates that correlated with toxicity. RESULTS: Linezolid was administered to 1050 patients; of these, 381 did not meet the inclusion criteria and 47 were excluded as therapy ceased for non-toxicity reasons. There were 105 of 622 (16.9%) patients assessed to have linezolid toxicity. Patients who experienced toxicity displayed a higher baseline creatinine (96.5 µmol/L vs. 79 µmol/L; P = 0.025), lower baseline platelet count (225 × 109/L vs. 278.5 × 109/L; P = 0.002) and received a longer course (median 21 vs. 14 days; P < 0.001) than those who did not. Linezolid TDM was performed in 144 patients (23%). Multivariable logistic regression demonstrated that TDM-guided appropriate dose adjustment significantly reduced the odds of linezolid toxicity (aOR = 0.45; 95% CI 0.21-0.96; P = 0.038) and a treatment duration > 28 days was no longer significantly associated with toxicity. CONCLUSIONS: This study confirmed that linezolid treatment-limiting toxicity remains a problem and suggests that TDM-guided dose optimisation may reduce the risk of toxicity and facilitate prolonged courses beyond 28 days.


Assuntos
Antibacterianos , Trombocitopenia , Humanos , Linezolida/toxicidade , Estudos Retrospectivos , Antibacterianos/efeitos adversos , Monitoramento de Medicamentos , Trombocitopenia/induzido quimicamente
7.
Nat Commun ; 12(1): 6310, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34728626

RESUMO

SHP2 mediates the activities of multiple receptor tyrosine kinase signaling and its function in endothelial processes has been explored extensively. However, genetic studies on the role of SHP2 in tumor angiogenesis have not been conducted. Here, we show that SHP2 is activated in tumor endothelia. Shp2 deletion and pharmacological inhibition reduce tumor growth and microvascular density in multiple mouse tumor models. Shp2 deletion also leads to tumor vascular normalization, indicated by increased pericyte coverage and vessel perfusion. SHP2 inefficiency impairs endothelial cell proliferation, migration, and tubulogenesis through downregulating the expression of proangiogenic SRY-Box transcription factor 7 (SOX7), whose re-expression restores endothelial function in SHP2-knockdown cells and tumor growth, angiogenesis, and vascular abnormalization in Shp2-deleted mice. SHP2 stabilizes apoptosis signal-regulating kinase 1 (ASK1), which regulates SOX7 expression mediated by c-Jun. Our studies suggest SHP2 in tumor associated endothelial cells is a promising anti-angiogenic target for cancer therapy.


Assuntos
Células Endoteliais/metabolismo , Neoplasias/patologia , Neovascularização Patológica/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Fatores de Transcrição SOXF/metabolismo , Animais , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/patologia , Humanos , Camundongos , Camundongos Knockout , Neoplasias/genética , Neoplasias/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11/deficiência , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Transdução de Sinais
8.
Cell Death Dis ; 12(10): 913, 2021 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615858

RESUMO

The nuclear receptor-binding SET domain 3 (NSD3) catalyzes methylation of histone H3 at lysine 36 (H3K36), and promotes malignant transformation and progression of human cancer. Its expression, potential functions and underlying mechanisms in pancreatic cancer are studied. Bioinformatics studies and results from local human tissues show that NSD3 is upregulated in human pancreatic cancer tissues, which is correlated with poor overall survival. In primary and established pancreatic cancer cells, NSD3 silencing (by shRNAs) or CRISPR/Cas9-induced NSD3 knockout potently inhibited cell proliferation, migration and invasion, while provoking cell cycle arrest and apoptosis. Conversely, ectopic expression of NSD3-T1232A mutation significantly accelerated proliferation, migration, and invasion of pancreatic cancer cells. H3K36 dimethylation, expression of NSD3-dependent genes (Prkaa2, Myc, Irgm1, Adam12, and Notch3), and mTOR activation (S6K1 phosphorylation) were largely inhibited by NSD3 silencing or knockout. In vivo, intratumoral injection of adeno-associated virus (AAV)-packed NSD3 shRNA potently inhibited pancreatic cancer xenograft growth in nude mice. These results suggest that elevated NSD3 could be an important driver for the malignant progression of pancreatic cancer.


Assuntos
Regulação Neoplásica da Expressão Gênica , Histona-Lisina N-Metiltransferase/genética , Proteínas Nucleares/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Animais , Apoptose/genética , Sistemas CRISPR-Cas/genética , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular/genética , Estudos de Coortes , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Metilação , Camundongos Nus , Mutação/genética , Invasividade Neoplásica , Proteínas Nucleares/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Medicine (Baltimore) ; 100(11): e23656, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33725924

RESUMO

ABSTRACT: Inflammation has been believed to contribute to coronavirus disease 2019 (COVID-19). Risk factors for death of COVID-19 pneumonia have not yet been well established.In this retrospective cohort study, we included the deceased patients in COVID-19 specialized ICU with laboratory-confirmed COVID-19 from Guanggu hospital area of Tongji Hospital from February 8th to March 30th. Demographic, clinical, laboratory, and outcome data were extracted from electronic medical records using a standard data collection form. We used Spearman rank correlation and Cox regression analysis to explore the risk factors associated with in-hospital death, especially the association between inflammatory cytokines and death.A total of 205 severe/critical COVID-19 pneumonia patients were admitted in the COVID-19 specialized ICU and 75 deceased patients were included in the final analysis. The median age of the deceasing patients was 70 years (IQR 65-79). The common symptoms were fever (78.9%), cough (70.4%), and expectoration (39.4%). The BNP and CRP levels were far beyond the normal reference range. In the Spearman rank correlation analysis, IL-8 was found to be significantly associated with the time from onset to death (rs= -0.30, P = .034) and that from admission to death (rs= -0.32, P = .019). Cox regression showed after adjusting age and sex, IL-8 levels were still significantly associated with the time from onset to death (P = .003) and that from admission to death (P  = .01).IL-8 levels were associated with in-hospital death in severe/critical COVID-19 patients, which could help clinicians to identify patients with high risk of death at an early stage.


Assuntos
COVID-19/mortalidade , Interleucina-8/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/sangue , China , Estado Terminal , Feminino , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Pneumonia/epidemiologia , Pneumonia/mortalidade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , SARS-CoV-2 , Índice de Gravidade de Doença
10.
Diabetes Res Clin Pract ; 169: 108448, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32946851

RESUMO

AIMS: Coronavirus disease 2019 (COVID-19) which is a novel pneumonia can rapidly progress to acute respiratory distress syndrome, septic shock, and multiple organ dysfunction syndrome. It has appeared in 196 countries around the world. We aimed to clarify the associations between fasting plasma glucose levels and mortality of COVID-19 in patients without diabetes. METHODS: We performed a retrospective, single-center study of 151 patients without diabetes in Tongji Hospital from January 1, 2020 to February 28, 2020. Past medical histories, clinical features and laboratory parameters were collected in these patients. RESULTS: Compared with survivors, non-survivors were more likely to have underlying medical conditions including hypertension and chronic pulmonary diseases. Non-survivors had higher C-reactive protein (CRP), procalcitonin (PCT), interleukin (IL)-2R, IL-6, IL-8 and, tumor necrosis factor-α (TNF-α) levels, while lower lymphocyte counts as compared with those of survivors (all P<0.05). Besides, patients with higher fasting plasma glucose (FPG) had higher IL-6, IL-8, CRP levels and mortality; while lower lymphocyte counts. After adjusting for age and gender, each tertile increment of FPG levels conferred 3.54-fold higher risks of death (odds ratio, 3.54; 95% confidential interval, 1.25-10.06, P=0.018). CONCLUSIONS: Non-survivors combined with more comorbidities, more severe infection, and worse liver, kidney and cardiac function in patients without diabetes. Additionally, fasting plasma glucose levels were significantly associated with the risk of death in patients even with normal FPG and HbA1c levels.


Assuntos
Glicemia/análise , COVID-19/mortalidade , Diabetes Mellitus , Jejum , SARS-CoV-2/isolamento & purificação , Idoso , Idoso de 80 Anos ou mais , COVID-19/sangue , COVID-19/epidemiologia , COVID-19/virologia , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida
11.
Endocrine ; 69(3): 477-480, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32705411

RESUMO

PURPOSE: This essay aims to propose suggestions on what we can learn from previous investigations to conduct further studies on the potential mechanisms underlying the effect of diabetes mellitus on COVID-19. METHODS: We reviewed some literature on diabetes and other types of coronavirus infection such as Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS) and made some summaries and comparisons. RESULTS: Diabetes affect the occurrence and progression of COVID-19. CONCLUSIONS: In-depth and comprehensive exploration of the mechanism of diabetes affecting COVID-19 should be carried out.


Assuntos
Infecções por Coronavirus , Complicações do Diabetes , Pandemias , Pneumonia Viral , Animais , Betacoronavirus , COVID-19 , Humanos , SARS-CoV-2
12.
Oncotarget ; 8(54): 92106-92118, 2017 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-29190901

RESUMO

Development of chemoresistance remains a major hurdle for triple negative breast cancer treatment. Previous studies suggest that CD44+/CD24- cells, subpopulation of cancer stem cells with self-renewing and tumor-initiating capacities, are partly responsible for chemoresistance and therapeutic failure of triple negative breast cancer. Therefore, novel agents that target cancer stem cells (CSCs) may improve the clinical outcome. KIF11 (kinesin family member 11), overexpressed in many cancer cells, is a molecular motor protein that plays essential role in mitosis. In this study, we assess its role in docetaxel resistant triple negative breast cancer (TNBC). We found that the expression of KIF11 was significantly increased in CD44+/CD24- subpopulation of docetaxel resistant TNBC cells. Knockdown of KIF11 resulted in a significant decrease in the percentage of CSCs and mammosphere formation. KIF11 knockdown also inhibits cell growth and induces cell cycle G2/M arrest followed by cell mitosis and apoptosis. Further docetaxel resistant TNBC xenograft models demonstrated that KIF11 inhibitor exerts growth inhibitory effect in vivo. Of note, we also found that KIF11 was highly expressed in TNBC and its expression was correlated with shorter disease free survival time. All these data indicate that KIF11 is critical for proliferation and self-renewal in TNBC tumor cells in vitro and in vivo, suggesting that KIF11 may be a promising therapeutic target for treating chemoresistant TNBC.

13.
ACS Appl Mater Interfaces ; 9(50): 43822-43829, 2017 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-29160691

RESUMO

Haptic memory, from the interaction of skin and brain, can not only perceive external stimuli but also memorize it after removing the external stimuli. For the mimicry of human sensory memory, a self-powered artificial tactile memorizing system was developed by coupling bionic electronic skin and nonvolatile resistive random access memory (RRAM). The tribotronic nanogenerator is utilized as electronic skin to transform the touching signal into electric pulse, which will be programmed into the artificial brain: RRAM. Because of the advanced structural designs and accurate parameter matching, including the output voltages and the resistances in different resistive states, the artificial brain can be operated in self-powered mode to memorize the touch stimuli with the responsivity up to 20 times. For demonstrating the application potential of this system, it was fabricated as an independently addressed matrix to realize the memorizing of motion trace in two-dimensional space. The newly designed self-powered nonvolatile system has broad applications in next-generation high-performance sensors, artificial intelligence, and bionics.

14.
Sci Rep ; 6: 32381, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27587001

RESUMO

In this paper, reduced graphene oxide functionalized with cobalt ferrite nanocomposites (CoFe@rGO) as a novel type of electromagnetic wave (EW) absorbing materials was successfully prepared by a three-step chemical method including hydrothermal synthesis, annealing process and mixing with paraffin. The effect of the sample thickness and the amount of paraffin on the EW absorption properties of the composites was studied, revealing that the absorption peaks shifted toward the low frequency regions with the increasing thickness while other conditions had little or no effect. It is found that the CoFe@rGO enhanced both dielectric losses and magnetic losses and had the best EW absorption properties and the wide wavelength coverage of the hole Ku-Band when adding only 5wt% composites to paraffin. Therefore, CoFe@rGO could be used as an efficient and lightweight EW absorber. Compared with the research into traditional absorbing materials, this figures of merit are typically of the same order of magnitude, but given the lightweight nature of the material and the high level of compatibility with mass production standards, making use of CoFe@rGO as an electromagnetic absorber material shows great potential for real product applications.

15.
J Colloid Interface Sci ; 484: 155-161, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27610470

RESUMO

Doping semiconductor nanowires (NWs) for altering their electrical and optical properties is a critical strategy for tailoring the performance of nanodevices. Here, we prepared in situ Al-doped ZnO nanowire arrays by using continuous flow injection (CFI) hydrothermal method to promote the conductivity. This reasonable method offers highly stable precursor concentration for doping that effectively avoid the appearance of the low conductivity ZnO nanosheets. Benefit from this, three orders of magnitude rise of the carrier concentration from 1016cm-3 to 1019cm-3 can be achieved compared with the common hydrothermal (CH) mothed in Mott-Schottky measurement. Possible effect of Al-doping was discussed by first-principle theory. On this basis, Al-doped ZnO nanowire arrays was developed as a binder-free conductive support for supercapacitor electrodes and high capacitance was triggered. It is owing to the dramatically decreased transfer resistance induced by the growing free-moving electrons and holes. Our results have a profound significance not merely in the controlled synthesis of other doping nanomaterials by co-precipitation method but also in the application of binder-free energy materials or other materials.

16.
Sci Rep ; 6: 29907, 2016 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-27443692

RESUMO

One-dimensional zinc oxide nanorods array exhibit excellent electron mobility and thus hold great potential as photoanode for photoelelctrochemical water splitting. However, the poor absorption of visible light and the prominent surface recombination hider the performance improvement. In this work, Au nanoparticles and aluminium oxide were deposited onto the surface of ZnO nanorods to improve the PEC performance. The localized surface plasmon resonance of Au NPs could expand the absorption spectrum to visible region. Simultaneously, the surface of passivation with Au NPs and Al2O3 largely suppressed the photogenerated electron-hole recombination. As a result, the optimal solar-to-hydrogen efficiency of ZnO/Au/Al2O3 with 5 cycles was 6.7 times that of pristine ZnO, ascribed to the synergistic effect of SPR and surface passivation. This research reveals that the synergistic effect could be used as an important method to design efficient photoanodes for photoelectrochemical devices.

17.
ACS Appl Mater Interfaces ; 8(9): 6137-43, 2016 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-26872101

RESUMO

Strain-induced piezoelectric potential (piezopotential) within wurtzite-structured ZnO can engineer the energy-band structure at a contact or a junction and, thus, enhance the performance of corresponding optoelectronic devices by effectively tuning the charge carriers' separation and transport. Here, we report the fabrication of a flexible self-powered ZnO/Spiro-MeOTAD hybrid heterojunction ultraviolet photodetector (UV PD). The obtained device has a fast and stable response to the UV light illumination at zero bias. Together with responsivity and detectivity, the photocurrent can be increased about 1-fold upon applying a 0.753% tensile strain. The enhanced performance can be attributed to more efficient separation and transport of photogenerated electron-hole pairs, which is favored by the positive piezopotential modulated energy-band structure at the ZnO-Spiro-MeOTAD interface. This study demonstrates a promising approach to optimize the performance of a photodetector made of piezoelectric semiconductor materials through straining.

18.
J Colloid Interface Sci ; 466: 291-6, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26748061

RESUMO

The design and optimization of supercapacitors electrodes nanostructures are critically important since the properties of supercapacitors can be dramatically enhanced by tunable ion transport channels. Herein, we demonstrate high-performance supercapacitor electrodes materials based on α-Fe2O3 by rationally designing the electrode microstructure. The large solid-liquid reaction interfaces induced by hollow nanoshuttle-like structures not only provide more active sites for faradic reactions but also facilitate the diffusion of the electrolyte into electrodes. These result in the optimized electrodes with high capacitance of 249 F g(-1) at a discharging current density of 0.5 A g(-1) as well as good cycle stability. In addition, the relationship between charge storage and the operating temperature has been researched. The specific capacitance has no significant change when the working temperature increased from 20 °C to 60 °C (e.g. 203 F g(-1) and 234 F g(-1) at 20 °C and 60 °C, respectively), manifesting the electrodes can work stably in a wide temperature range. These findings here elucidate the α-Fe2O3 hollow nanoshuttles can be applied as a promising supercapacitor electrode material for the efficient energy storage at various potential temperatures.

19.
Sci Rep ; 5: 9853, 2015 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-25928429

RESUMO

Previous study revealed that the protective effect of TIGAR in cell survival is mediated through the increase in PPP (pentose phosphate pathway) flux. However, it remains unexplored if TIGAR plays an important role in DNA damage and repair. This study investigated the role of TIGAR in DNA damage response (DDR) induced by genotoxic drugs and hypoxia in tumor cells. Results showed that TIGAR was increased and relocated to the nucleus after epirubicin or hypoxia treatment in cancer cells. Knockdown of TIGAR exacerbated DNA damage and the effects were partly reversed by the supplementation of PPP products NADPH, ribose, or the ROS scavenger NAC. Further studies with pharmacological and genetic approaches revealed that TIGAR regulated the phosphorylation of ATM, a key protein in DDR, through Cdk5. The Cdk5-AMT signal pathway involved in regulation of DDR by TIGAR defines a new role of TIGAR in cancer cell survival and it suggests that TIGAR may be a therapeutic target for cancers.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Quinase 5 Dependente de Ciclina/genética , Dano ao DNA/genética , Reparo do DNA/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Via de Pentose Fosfato/genética , Transdução de Sinais/genética , Proteínas Reguladoras de Apoptose , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/genética , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Epirubicina/farmacologia , Células Hep G2 , Humanos , Hipóxia/genética , Hipóxia/metabolismo , NADP/genética , Via de Pentose Fosfato/efeitos dos fármacos , Monoéster Fosfórico Hidrolases , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
20.
ACS Appl Mater Interfaces ; 7(13): 7382-8, 2015 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-25786156

RESUMO

In this work, a high-performance, forming-free memristor based on Au/ZnO nanorods/AZO (Al-doped ZnO conductive glass) sandwich structure has been developed by rapid hydrogen annealing treatment. The Ron/Roff rate is dramatically increased from ∼10 to ∼10(4) after the surface treatment. Such an enhanced performance is attributed to the introduced oxygen vacancies layer at the top of ZnO nanorods. The device also exhibits excellent switching and retention stability. In addition, the carrier migration behavior can be well interpreted by classical trap-controlled space charge limited conduction, which verifies the forming of conductive filamentary in low resistive state. On this basis, Arrhenius activation theory is adopted to explain the drifting of oxygen vacancies, which is further confirmed by the time pertinence of resistive switching behavior under different sweep speed. This fabrication approach offers a useful approach to enhance the switching properties for next-generation memory applications.

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