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1.
Artigo em Inglês | MEDLINE | ID: mdl-31418545

RESUMO

Zinc-based battery chemistries have lately drawn great attention for grid-scale energy storage due to their material abundance and high safety. However, the low Coulombic efficiency (CE) and dendrite growth of zinc (Zn) anodes and the limited working voltage of current oxide cathodes are the major barriers hindering the development of rechargeable Zn-based batteries (RZBs). Here, we report an ultrafast and high-voltage Zn battery in a new cell configuration employing a graphite cathode, a Zn anode, and nonaqueous 1 M zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2) in acetonitrile (AN) electrolyte. This RZB operates through the (de)intercalation of TFSI- anions into the graphite and the electrochemical Zn2+ plating/stripping at the anode. The optimized Zn(TFSI)2/AN electrolyte features high reductive/oxidative stability, good ionic conductivity (∼28 mS cm-1), and low viscosity (∼0.4 mPa·s), enabling the unprecedented cycling stability (over 1000 h) of the Zn anode with a dendrite-free morphology, the ultrafast Zn plating/stripping with a high CE (>99%), and the good compatibility with the graphite cathode. Consequently, this RZB exhibits a high average output voltage (2.2 V), a high energy/power density (86.5 Wh kg-1 at 4400 W kg-1), and a long cycle life (97.3% capacity retention after 1000 cycles). The present work offers new insights and opportunities to the Zn-based electrochemistry.

2.
Int J Nanomedicine ; 14: 5849-5863, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31440050

RESUMO

Background: Topical application of tacrolimus (FK506) was effective in treating atopic dermatitis (AD); however, the therapeutic efficiency is hampered by its poor penetration into the skin and local side effects of transient irritation symptoms with a burning sensation, a feeling of warmth or heat. Menthol and camphor have been widely used in topical compound formulations for adjunctive pharmacotherapy for antipruritics and analgesics owing to their cool nature, and both present skin penetration enhancing effects. Moreover, they can form a liquid eutectic oil to solubilize hydrophobic drugs. Purpose: Taking advantages of menthol/camphor eutectic (MCE), this work aims to integrate FK506 into MCE to construct a microemulsion system, i.e., FK506 MCE ME, which simultaneously enhances the percutaneous delivery and treatment efficacy, while reduces the side effects of FK506. Methods: The formulation of FK506 MCE ME was optimized and characterized. Different formulations containing FK506 were topically administered to treat 1-chloro-2, 4-dinitrobenzene (DNCB)-induced murine AD. Results: MCE solubilized FK506. FK506 in MCE ME penetrated skin in vitro more than in the commercial ointment, and MCE predominantly exerted the enhancing effects in MCE ME. FK506 MCE ME or FK506 MCE ME gel had greater effects on clinical symptoms, histological analysis, and IgE than did commercial FK506. The anti-pruritic and down-regulation of substance P effects of MCE ME vehicle mitigated the side effects of FK506 application. Conclusion: MCE ME presented the excellent properties of simultaneously enhancing the percutaneous delivery and treatment efficacy, while reducing the side effects of FK506 for AD. Therefore, MCE ME is a promising nanoscale system for FK506 to effectively treating AD with low irritation and high medication adherence. Chemical compounds studied in this article: Tacrolimus (PubChem CID: 445643); menthol (PubChem CID: 1254); camphor (PubChem CID: 2537).

3.
J Card Surg ; 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31374583

RESUMO

Primary cardiac tumors are very rare and generally benign. The most common type, cardiac rhabdomyoma, comprises 45% to 75% of primary cardiac tumors. Cardiac rhabdomyoma is a rare benign tumor that commonly presents with tuberous sclerosis. We present a case of an infant with multifocal cardiac rhabdomyomas with an atrial septal defect and tricuspid insufficiency and no sign of tuberous sclerosis. She was successfully treated with an operation, the treatment plan included mass resection, tricuspid annuloplasty, and closure of the patent foramen ovale. The right atrial lesion was resected entirely, while the lobulated lesion in the right ventricle was resected as two pieces. There was no evidence of recurrence 1 year after the surgery.

4.
Fish Shellfish Immunol ; 93: 743-751, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31408731

RESUMO

White shrimp Litopenaeus vannamei are widely cultured in the world and white spot syndrome virus (WSSV) led to huge economic losses in the shrimp industry every year. In the present study, miRNAs involved in the response of shrimp L. vannamei to WSSV infection were obtained through the Illumina HiSeq 2500 high-throughput next-generation sequencing technique. A total number of 7 known miRNAs and 54 putative novel miRNAs were obtained. Among them, 14 DEMs were identified in the shrimp infected with WSSV. The putative target genes of these DEMs were related to host immune response or signaling pathways, indicating the importance of miRNAs in shrimp against WSSV infection. The results will provide information for further research on shrimp response to virus infection and contribute to the development of new strategies for effective protection against WSSV infections.

5.
Asian J Surg ; 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31255465

RESUMO

OBJECTIVE: This study evaluates growth of pulmonary artery (PA) between different age groups after Modified Blalock-Taussig shunt (MBTS) based on a single center experience. METHODS: We retrospective analyzed outcomes of 90 patients undergoing MBTS in our institute from January 1, 2010 to May 1, 2018. Patients were divided into three groups: Group 1, ≦2 months, Group 2, >2 months, ≦24 wmonths, Group 3, >24 months. The outcome included PA growth, overall survival rates and postoperative complications. RESULTS: 23 patients were involved in Group 1, while 49 in Group 2 and 18 in Group 3. The diameter of the PA, McGoon ratio, Nakata index and the oxygen saturation increased significantly after MBTS. Compared to pre-MBTS, there was no statistically significant increase of McGoon ratio in Group 3 after performing MBTS, but it witnessed less secondary cardiac surgery rate compared with Group 2 (11.11% vs. 48.98%, P = 0.005). Cumulative survival rates of three groups were 60.53%, 85.70%, 94.40% at 1 year; 60.53%, 78.30%, 87.75% at 3 years and 60.53%, 78.30%, 87.75% at 5 years. Multivariable analysis showed diastolic blood pressure <30 mmHg [OR 14.14 (1.92-104.32), P = 0.009], cardiopulmonary bypass use [OR 16.79 (2.05-137.67), P = 0.009] and single ventricle anomaly [OR 8.80 (1.18-65.54), P = 0.034] were predictors of perioperative mortality. CONCLUSION: MBTS in our institute is a conventional and effective procedure for growth of PA especially for patients younger than 24 months. Patients with biventricular anomaly, no cardiopulmonary bypass use in surgery and relatively high postoperative diastolic blood pressure will likely offer a good prognosis.

6.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(5): 528-534, 2019 May 28.
Artigo em Chinês | MEDLINE | ID: mdl-31303616

RESUMO

OBJECTIVE: To explore the role of P53, pairing box gene 8 antibody (PAX8), and calcium omentum protein (Calretinin) in the origin of epithelial ovarian cancer.
 Methods: A total of 63 tissue samples of ovarian tumor and fallopian tubes were collected. Immunohistochemistry methods were used to analyze the expression of P53, PAX8, and Calretinin. The relationship between these protein levels and the classification of ovarian tumors was evaluated.
 Results: In epithelial ovarian cancer, the P53 or PAX8 was correlated with the occurrence of high-grade carcinoma, while the calretinin was correlated with the occurrence of low-grade carcinoma (P<0.05). The combination of PAX8 with Calretinin was correlated with the grade of ovarian tumor (P<0.05). The combination of P53 with Calretinin was correlated with the grade of tumor (P<0.05). The combination of P53 with PAX8 was correlated with the grade of tumor (P<0.05). The expression of P53 in fallopian tubes was correlated with the malignant degree of epithelial ovarian cancer (P<0.05). The degree of fallopian tube lesions in patients with ovarian cancer was correlated with epithelial ovarian cancer. The malignant lesions of tubal epithelium was correlated with high-grade carcinoma, while the normal or atypical hyperplasia of tubal epithelium was correlated with low-grade carcinoma (P<0.05).
 Conclusion: P53 and Calretinin combined with PAX8 show a synergistic effect on the differentiation of epithelial ovarian cancer grade. The morphology of HE and the expression of TP53 in the fallopian tube epithelium play an auxiliary role in the diagnosis of epithelial ovarian cancer.


Assuntos
Carcinoma Epitelial do Ovário , Neoplasias Ovarianas , Epitélio , Tubas Uterinas , Feminino , Humanos , Fator de Transcrição PAX8
7.
J Mol Graph Model ; 92: 112-122, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31351319

RESUMO

HIV-1 protease (HIV-1-pr) plays an important role in viral replication and maturation, making it one of the most attractive targets for anti-retroviral therapy. To design new effective inhibitors able to combat drug resistance in mutant HIV-1-pr variants, it is essential to gain further understanding about the mechanisms by which the recently proposed inhibitors deactivate the mutant HIV-1-pr variants. In the present work, we explored the interactions between two P2-ligands (DRV, and one new derivative, 4UY) with wild type (WT) and two multiple mutant HIV-1-pr variants (p20 and p51) with all atom molecular dynamics (MD) simulations, binding free energy calculations, and principal component analysis (PCA). The trajectories of MD simulations show that both 4UY and DRV primarily bind with the active sites, flap and 80s loop regions of HIV-1-pr variants through either hydrogen bonds or hydrophobic interactions. More hydrogen bonds and hydrophobic interactions were located for 4UY/HIV-1-pr complexes than for DRV/HIV-1-pr counterparts. More importantly, 4UY was found to have an extra hydrogen bond with the backbone of Gly48' in the flap region of the HIV-1-prs. The flap tip-tip distance (I50-I50') and flap tip-active site distance (I50-D25 and I50'-D25') indicate that the flaps turn more closed in 4UY bound HIV-1-prs than DRV bound ones, and the former also have more compact hydrophobic cavities than the latter. Further, the vector projections from PCA indicate that 4UY/DRV inhibitor binding projects the closing of flap in HIV-1-pr variants. In line with the above trajectory analysis, the thermodynamics calculation with MM-PBSA method suggests much stronger binding affinity for 4UY/HIV-1-pr than DRV/HIV-1-pr by 4.3-6.4 kcal/mol. Although p20 and p51 also induce weaker binding due to multiple mutants for 4UY inhibitor by 1.9-1.8 kcal/mol, their bindings to the new P2 ligand (4UY) are indeed significantly enhanced as compared to DRV. The thermodynamic components responsible for the binding differences and the contribution from key residues to the binding were also discussed in detail.

8.
Int J Biol Sci ; 15(5): 1052-1071, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31182925

RESUMO

In pursuit of a novel approach in colon cancer therapy, we explored the ability of ruthenium baicalein complex to eradicate colon cancer by efficiently targeting various apoptotic pathways on human colon cancer cell line and on a DMH and DSS induced murine model of colorectal cancer. In this study, we provide direct proof of the chemotherapeutic potential of the ruthenium baicalein complex by activating p-53 dependent intrinsic apoptosis and modulating the AKT/mTOR and WNT/ß- catenin pathways. The ruthenium baicalein complex was synthesized and its characterizations were accomplished through various spectroscopic techniques followed by assessment of antioxidant potential by DPPH, FRAP, and ABTS methods. In vitro study established that the complex increased p53 and caspase-3 expressions while down regulating VEGF and mTOR expression, induced apoptosis, and DNA fragmentation in the HT-29 cells. Acute and sub-acute toxicity study was also considered and results from in vivo study revealed that complex was effective in suppressing ACF multiplicity and hyperplastic lesions and also raised the CAT, SOD, and glutathione levels. Furthermore, the complex decreased cell proliferation and increased apoptotic events in tumor cells correlated with the upregulation of Bax and downregulation of Bcl2, WNT and ß- catenin expressions. Our findings from the in vitro and in vivo study provide robust confirmation that ruthenium baicalein complex possesses a potential chemotherapeutic activity against colon cancer and is competent in reducing ACF multiplicity, hyperplastic lesions in the colon tissues of rats by inducing apoptosis.

9.
Artigo em Inglês | MEDLINE | ID: mdl-31216689

RESUMO

The association effect between provincial transportation carbon emissions has become an important issue in regional carbon emission management. This study explored the relationship and development trends associated with regional transportation carbon emissions. A social network method was used to analyze the structural characteristics of the spatial association of transportation carbon emissions. Indicators for each of the structural characteristics were selected from three dimensions: The integral network, node network, and spatial clustering. Then, this study established an association network for transportation carbon emissions (ANTCE) using a gravity model with China's provincial data during the period of 2007 to 2016. Further, a block model (a method of partitioning provinces based on the information of transportation carbon emission) was used to group the ANTCE network of inter-provincial transportation carbon emissions to examine the overall association structure. There were three key findings. First, the tightness of China's ANTCE network is growing, and its complexity and robustness are gradually increasing. Second, China's ANTCE network shows a structural characteristic of "dense east and thin west." That is, the transportation carbon emissions of eastern provinces in China are highly correlated, while those of central and western provinces are less correlated. Third, the eastern provinces belong to the two-way spillover or net benefit block, the central regions belong to the broker block, and the western provinces belong to the net spillover block. This indicates that the transportation carbon emissions in the western regions are flowing to the eastern and central regions. Finally, a regression analysis using a quadratic assignment procedure (QAP) was used to explore the spatial association between provinces. We found that per capita gross domestic product (GDP) and fixed transportation investments significantly influence the association and spillover effects of the ANTCE network. The research findings provide a theoretical foundation for the development of policies that may better coordinate carbon emission mitigation in regional transportation.

10.
BMC Cancer ; 19(1): 630, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31242895

RESUMO

BACKGROUND: Globally, the incidence and mortality rates of gastric cancer are high, and its poor prognosis is closely related to tumor recurrence and metastasis. Therefore, the molecular mechanisms associated with the migration and invasion of gastric cancer cells are important for gastric cancer treatment. Previously, TSPAN9 has been reported to inhibit gastric cancer cell migration; however, the underlying molecular mechanism remains unclear. METHODS: Human gastric adenocarcinoma cell lines, SGC7901 and AGS, were cultured in vitro. TSPAN9 expression was determined by RT-PCR, western blot analysis, and immunohistochemistry in gastric cancer and tumor-adjacent tissues. Following the over-expression and knockdown of TSPAN9, wound healing and cell invasion assays were performed and EMT-related protein expression was evaluated to analyze the invasion and migration of gastric cancer cells. TSPAN9 expression and the invasion and metastasis of gastric cancer cells were observed by the functional assays following EMILIN1 over-expression. RESULTS: Inhibiting TSPAN9 expression significantly promoted the migration and invasion of gastric cancer cells. In addition, immunofluorescence co-localization and co-immunoprecipitation analysis revealed closely related expression of EMILIN1 and TSPAN9. Moreover, EMILIN1 can synergistically boost the tumor suppressive effect of TSPAN9, which may be produced by promoting TSPAN9 expression. CONCLUSIONS: We have demonstrated that EMILIN1 induces anti-tumor effects by up-regulating TSPAN9 expression in gastric cancer. Hence, membrane proteins TSPAN9 and EMILIN1 may represent novel therapeutic targets for the treatment of gastric cancer.

11.
Toxicol Mech Methods ; 29(7): 467-477, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31050317

RESUMO

Nickel (Ni) is a common environmental pollutant, which has toxic effects on reproductive system. Nowadays, nano-selenium (Nano-Se) has aroused great attention due to its unique antioxidant effect, excellent biological activities and low toxicity. The aim of this study was to explore the protective effects of Nano-Se on NiSO4-induced testicular injury and apoptosis in rat testes. Nickel sulfate (NiSO4) (5 mg/kg b.w.) was administered intraperitoneally and Nano-Se (0.5, 1, and 2 mg Se/kg b.w., respectively) was given by oral gavage in male Sprague-Dawley rats. Histological changes in the testes were determined by H&E staining. The terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and immunohistochemistry were performed to evaluate the apoptosis in testes. Expression levels of mitochondrial apoptosis-related genes and proteins were analyzed by RT-qPCR and Western blot. The results showed that Nano-Se improved lesions of testicular tissue induced by NiSO4. Nano-Se significantly alleviated NiSO4-induced apoptosis in rat testes, as well as significantly downregulated the Bak, cytochrome c, caspase-9 and caspase-3 and upregulated Bcl-2 expression levels, all of which were involved in mitochondria-mediated apoptosis. Altogether, we concluded that Nano-Se may potentially exert protective effects on NiSO4-induced testicular injury and attenuate apoptosis, at least partly, via regulating mitochondrial apoptosis pathways in rat testes.

12.
Environ Sci Technol ; 53(12): 6927-6936, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31117534

RESUMO

Promotion of iron solubility using ligands is the preliminary step in the homogeneous electro-Fenton (EF) process at a mild pH, but the chelate efficiencies of most organic ligands are unsatisfactory, resulting in insufficient Fe(II) availability. In this study, atomic H* was, for the first time, introduced to the EF process to accelerate the regeneration of the Fe(II)-complex at a mild pH using a Ni-deposited carbon felt (Ni-CF) cathode. The introduction of atomic H* significantly elevated total organic carbon (TOC) abatement of ciprofloxacin (CIP) from 42% (CF) to 81% (Ni-CF) at a natural pH. In the presence of humic acids (HAs), atomic H* introduced via Ni-CF enhanced the CIP degradation rate to 10 times that of the CF at a mild pH. The electron spin resonance (ESR), density functional theory (DFT) calculations, electrochemical characterization, and in situ electrochemical Raman study clearly demonstrated that the atomic H* generated from the Ni-CF cathode was highly efficient at reducing Fe(III)-complexes at a natural pH. Additionally, the Ni-CF could generate atomic H* without significant nickel leaching. Thus, the atomic H* could continuously facilitate iron cycling and, consequently, enhance pollutant mineralization via the homogeneous EF process at a mild pH in an environmentally friendly manner.

13.
Stem Cell Res Ther ; 10(1): 125, 2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30999928

RESUMO

Stem cell transplantation (SCT) has become a promising way to treat ischemic heart failure (IHF). We performed a large-scale meta-analysis of randomized clinical trials to investigate the efficacy and safety of SCT in IHF patients. Randomized controlled trials (RCTs) involving stem cell transplantation for the treatment of IHF were identified by searching the PubMed, EMBASE, SpringerLink, Web of Science, and Cochrane Systematic Review databases as well as from reviews and the reference lists of relevant articles. Fourteen eligible randomized controlled trials were included in this study, for a total of 669 IHF patients, of which 380 patients were treated with SCT. The weighted mean difference (WMD) was calculated for changes in the New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF), left ventricular end-diastolic and end-systolic volumes (LVEDV and LVESV), and Canadian Cardiovascular Society (CCS) angina grade using a fixed effects model, while relative risk (RR) was used for mortality. Compared with the control group, SCT significantly lowered the NYHA class (MD = - 0.73, 95% CI - 1.32 to - 0.14, P < 0.05), LVESV (MD = - 14.80, 95% CI - 20.88 to - 8.73, P < 0.05), and CCS grade (MD = - 0.81, 95% CI - 1.45 to - 0.17, P < 0.05). Additionally, SCT increased LVEF (MD = 6.55, 95% CI 5.93 to 7.16, P < 0.05). However, LVEDV (MD = - 0.33, 95% CI - 1.09 to 0.44, P > 0.05) and mortality (RR = 0.86, 95% CI 0.45 to 1.66, P > 0.05) did not differ between the two groups. This meta-analysis suggests that SCT may contribute to the improvement of LVEF, as well as the reduction of the NYHA class, CCS grade, and LVESV. In addition, SCT does not affect mortality.

14.
J Hazard Mater ; 373: 417-424, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-30939424

RESUMO

The removal performance and mechanisms of diatrizoate (DTA), a typical iodinated contrast medium, from water by nano-sized zero-valent iron (nZVI) under aerobic conditions were investigated in this study. Reactive oxygen species (ROS) and transformation products were detected with electron spin resonance and liquid chromatography electrospray ionization tandem mass spectrometry, respectively. Furthermore, the effects of several operational parameters on DTA removal were illustrated. The results showed that nZVI had a much higher DTA removal ability compared to microscale zero-valent iron (mZVI) in the presence of oxygen. Moreover, the detection of ROS and I- as well as the analysis of intermediate products suggested a combination of oxidation and reduction pathways for DTA removal by nZVI under aerobic conditions. Additionally, a high dosage of nZVI and acidic conditions led to the enhancement of DTA removal, while nZVI aging, as well as chloride and nitrate ions in the solution, had negative effects on the degradation of DTA by nZVI in the presence of oxygen.

15.
Molecules ; 24(5)2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30862068

RESUMO

Enterovirus 71 (EV-A71) is the main causative pathogen of childhood hand, foot and mouth disease. Effective medicine is currently unavailable for the treatment of this viral disease. Using the fragment-hopping strategy, a series of 2-aryl-isoindolin-1-one compounds were designed, synthesized and investigated for their in vitro antiviral activity towards multiple EV-A71 clinical isolates (H, BrCr, Shenzhen98, Jiangsu52) in Vero cell culture in this study. The structure⁻activity relationship (SAR) studies identified 2-phenyl-isoindolin-1-ones as a new potent chemotype with potent antiviral activity against EV-A71. Ten out of the 24 tested compounds showed significant antiviral activity (EC50 < 10 µM) towards four EV-A71 strains. Compounds A3 and A4 exhibited broad and potent antiviral activity with the 50% effective concentration (EC50) values in the range of 1.23⁻1.76 µM. Moreover, the selectivity indices of A3 and A4 were significantly higher than those of the reference compound, pirodavir. The western blotting experiment indicated that the viral VP1 was significantly decreased at both the protein and RNA level in a dose-dependent manner following treatment with compound A3. Moreover, compound A3 inhibited the viral replication by acting on the virus entry stage. In summary, this study led to the discovery of 2-aryl-isoindolin-1-ones as a promising scaffold with potent anti-EV-A71 activities, which deserves further in-depth studies.


Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Enterovirus Humano A/efeitos dos fármacos , Isoindóis/síntese química , Isoindóis/farmacologia , Animais , Antivirais/química , Linhagem Celular , Cercopithecus aethiops , Enterovirus Humano A/isolamento & purificação , Enterovirus Humano A/fisiologia , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Humanos , Isoindóis/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Células Vero , Replicação Viral/efeitos dos fármacos
16.
Bioelectrochemistry ; 128: 9-16, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30884361

RESUMO

Bioelectrochemical systems (BESs) have shown great potential for azo dye removal. However, comprehensive evaluation of the bioelectrochemical decolorization performance for reactive diazo dyes remains limited, particularly the kinetics and operation parameter optimization. This study evaluated the decolorization of the diazo dye Reactive Black 5 (RB5) in BESs, particularly with regard to kinetics, parameter optimization using response surface methodology (RSM), and the degradation pathway. The results indicated that the pseudo-first-order kinetic rate constant of RB5 decolorization increased from 0.023 ±â€¯0.001 to 0.146 ±â€¯0.008 h-1 with a decrease in cathode potential from -400 mV to -500 mV. RSM optimization suggested that the linear effects of RB5 concentration, cathode potential and hydraulic retention time (HRT), interaction of RB5 concentration with cathodic HRT, and the quadratic effect of cathodic HRT were most influential on the bioelectrochemical decolorization of RB5. Further, the decolorized RB5 products in the BESs were characterized by ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, and liquid chromatograph-mass spectrometry. From this, a potential decolorization mechanism is proposed based on cleavage of azo bonds.


Assuntos
Compostos Azo/química , Cor , Corantes/química , Técnicas Eletroquímicas/métodos , Cromatografia Líquida , Eletrodos , Estudos de Viabilidade , Cinética , Microscopia Eletrônica de Varredura , Naftalenossulfonatos/química , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Espectrometria de Massas em Tandem
17.
Anal Bioanal Chem ; 411(12): 2531-2543, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30828757

RESUMO

In this work, a novel ratiometric fluorescent sensor, based on carbon dots (CDs) and gold nanoclusters (AuNCs), is developed for highly sensitive and selective visual colorimetric detection of Cu2+ and alkaline phosphatase (ALP). The ratiometric fluorescent sensor was synthesized by covalently linking 11-mercaptoundecanoic acid (11-MUA)-stabilized AuNCs to the surface of amino-functionalized CD/SiO2 nanoparticles. The red fluorescence of the AuNCs can be quenched by Cu2+ owing to coordination between Cu2+ and 11-MUA; however, the blue emission of the CDs was insensitive to Cu2+ owing to the protective silica shell. The quenching of the AuNCs' fluorescence returned when PPi was added because of the higher affinity between Cu2+ and PPi than that between Cu2+ and 11-MUA. In the presence of ALP, PPi was catalytically hydrolyzed into phosphate (Pi), which showed a much weaker affinity for Cu2+. Thus, Cu2+ ions were released, and the fluorescence of the AuNCs was quenched once more. Based on this principle, Cu2+ and ALP could be simultaneously detected. The developed ratiometric fluorescent sensor could detect Cu2+ over a range from 0.025 to 4 µM with a detection limit of 0.013 µM and ALP over a range from 0.12 to 15 U/L with a detection limit of 0.05 U/L. The present method was successfully applied for the detection of Cu2+ and ALP in real water samples and in human serum samples, respectively. This ratiometric fluorescent approach may provide a highly sensitive and accurate platform for visual Cu2+ and ALP sensing in environmental monitoring and medical diagnosis.


Assuntos
Fosfatase Alcalina/análise , Carbono/química , Cobre/análise , Corantes Fluorescentes/química , Ouro/química , Nanopartículas Metálicas/química , Pontos Quânticos , Fosfatase Alcalina/sangue , Catálise , Difosfatos/química , Humanos , Limite de Detecção , Microscopia Eletrônica de Transmissão , Dióxido de Silício/química , Espectrometria de Fluorescência/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
18.
Environ Sci Technol ; 53(8): 4397-4405, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30908036

RESUMO

Pyrogenic carbonaceous matter (PCM) catalyzes the transformation of a range of organic pollutants by sulfide in water; however, the mediation mechanisms are not fully understood. In this study, we observed for the first time that the degradation of azo dyes by sulfide initially underwent a lag phase followed by a fast degradation phase. Interestingly, the presence of PCM only reduced the lag phase length of the azo dye decolorization but did not significantly enhance the reaction rate in the fast degradation phase. An analysis of the azo dye reduction and polysulfide formation indicated that PCM facilitated the transformation of sulfide into polysulfides, including disulfide and trisulfide, resulting in fast azo dye reduction. Moreover, the oxygen functional groups of the PCM, especially the quinones, may play an important role in the transformation of sulfide into polysulfides by accelerating the electron transfer. The results of this study provide a better understanding of the PCM-mediated abiotic transformation of organic pollutants by sulfide in anaerobic aqueous environments.

19.
Mol Plant Microbe Interact ; 32(9): 1134-1147, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30920344

RESUMO

Azorhizobium caulinodans ORS571 can induce nodule formation on the roots and the stems of its host legume, Sesbania rostrata. Plant exudates are essential in the dialogue between microbes and their host plant and, in particular, amino acids can play an important role in the chemotactic response of bacteria. Histidine, arginine, and aspartate, which are the three most abundant amino acids present in S. rostrata seed exudates, behave as chemoattractants toward A. caulinodans. A position-specific-iterated BLAST analysis of the methyl-accepting chemotaxis proteins (MCPs) (chemoreceptors) in the genome of A. caulinodans was performed. Among the 43 MCP homologs, two MCPs harboring a dCache domain were selected as possible cognate amino acid MCPs. After analysis of relative gene expression levels and construction of a gene-deleted mutant strain, one of them, AZC_0821 designed as TlpH, was confirmed to be responsible for the chemotactic response to the three amino acids. In addition, it was found that these three amino acids can also influence chemotaxis of A. caulinodans independently of the chemosensory receptors, by being involved in the increase of the expression level of several che and fla genes involved in the chemotaxis pathway and flagella synthesis. Thus, the contribution of amino acids present in seed exudates is directly related to the role as chemoattractants and indirectly related to the role in the regulation of expression of key genes involved in chemotaxis and motility. This "dual role" is likely to influence the formation of biofilms by A. caulinodans and the host root colonization properties of this bacterium.

20.
J Nurs Manag ; 27(4): 688-696, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30702790

RESUMO

AIM: This study investigated the relationship between work engagement and inclusive leadership in Chinese hospital head nurses. Besides, it explored the effect of the mediating role of inclusive leadership in the relationship between work engagement and innovative behaviour among Chinese hospital head nurses. BACKGROUND: Head nurses are essential in the group of registered nurses who are to pass the Chinese licensure examination for nurses. Their work engagement and innovative behaviour are beneficial to improve the quality, efficiency and competitiveness of nursing services. However, little is known about the mediating role of inclusive leadership in the relationship between work engagement and innovative behaviour. METHODS: In April 2018, a total of 374 Chinese head nurses were surveyed with a Work Engagement Scale, an Inclusive Leadership Scale and an Innovative Behavior Scale. Because the data were normally distributed in our study, Pearson's correlation coefficient (r) was used to conduct the correlation analysis of study variables. Multiple linear regression analysis was used to explore the factors of innovative behaviour. Model 4 of Hayes's (2013) PROCESS macro and Bootstrap method was used to examine the mediating role of inclusive leadership. RESULT: Inclusive leadership was significantly and positively correlated to innovative behaviour and work engagement (p < 0.01). Moreover, work engagement was correlated with innovative behaviour (p < 0.01). In addition, hospital level, publishing papers, work engagement and inclusive leadership were the factors of head nurses' innovative behaviour (p < 0.01). Inclusive leadership partially mediated the relationship between work engagement and innovative behaviour, accordingly. CONCLUSION: Work engagement affects innovative behaviour among Chinese head nurses, and inclusive leadership is a mediator in the relationship. We should take measures to improve the leaders' level of inclusive leadership, in order to strengthen head nurses' innovative behaviour. IMPLICATIONS FOR NURSING MANAGEMENT: According to the results of the study, the leaders of head nurses should pay attention to improve head nurses' innovative behaviour, inclusive leadership, work engagement, and the quality and competitiveness of nursing.

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