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1.
Org Lett ; 23(2): 279-284, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33352055

RESUMO

An efficient divergent approach of Pd-catalyzed C-H oxygenation of polyaromatic rings is described. Reversible directing groups enable regiospecific peri- and ortho-oxygenation to readily access a wide array of polyaromatic phenols without pre- and postmanipulation of directing groups. The systematic mechanistic investigation, including deuterium-labeling experiments, palladacycle trapping, and DFT calculations, reveals that the tunable ligand-assisted C-H bond cleavage played a crucial role during the reaction process.

2.
J Nanobiotechnology ; 18(1): 116, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32847586

RESUMO

BACKGROUND: The management of metastatic cancer remains a major challenge in cancer therapy worldwide. The targeted delivery of chemotherapeutic drugs through rationally designed formulations is one potential therapeutic option. Notably, excipient-free nanodispersions that are entirely composed of pharmaceutically active molecules have been evaluated as promising candidates for the next generation of drug formulations. Formulated from the self-assembly of drug molecules, these nanodispersions enable the safe and effective delivery of therapeutic drugs to local disease lesions. Here, we developed a novel and green approach for preparing nanoparticles via the self-assembly of rhein (RHE) and doxorubicin (DOX) molecules, named RHE/DOX nanoparticles (RD NPs); this assembly was associated with the interaction force and did not involve any organic solvents. RESULTS: According to molecular dynamics (MD) simulations, DOX molecules tend to assemble around RHE molecules through intermolecular forces. This intermolecular retention of DOX was further improved by the nanosizing effect of RD NPs. Compared to free DOX, RD NPs exerted a slightly stronger inhibitory effect on 4T1 cells in the scratch healing assay. As a dual drug-loaded nanoformulation, the efficacy of RD NPs against tumor cells in vitro was synergistically enhanced. Compared to free DOX, the combination of DOX and RHE in nanoparticles exerted a synergistic effect with a combination index (CI) value of 0.51 and showed a stronger ability to induce cell apoptosis. Furthermore, the RD NP treatment not only effectively suppressed primary tumor growth but also significantly inhibited tumor metastasis both in vitro and in vivo, with a better safety profile. CONCLUSIONS: The generation of pure nanodrugs via a self-assembly approach might hold promise for the development of more efficient and novel excipient-free nanodispersions, particularly for two small molecular antitumor drugs that potentially exert synergistic antiproliferative effects on metastatic breast cancer.

3.
Pathol Oncol Res ; 26(4): 2621-2632, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32632900

RESUMO

Due to the different mechanisms of cell-free DNA production, the single-stranded DNA to double-stranded DNA ratio in blood maybe different between healthy individuals and gastric cancer (GC) patients. We aimed to explore the potential application of this ratio in GC diagnosis. The plasma cell-free DNA extracts from 118 healthy individuals and 106 GC patients were prepared. The levels of single-stranded DNA or double-stranded DNA in plasma, and the single-stranded DNA to double-stranded DNA ratio on the diagnostic efficiency for GC were assessed with ROC curve. The relationships between this ratio and the clinical characteristics of GC patients were analyzed. The ratios in 63 GC patients before and after surgery were compared. In healthy individuals, the single-stranded DNA to double-stranded DNA ratio was not affected by factors including age, gender and BMI, and subjected to normal distribution (P = 0.1090). GC patients had a lower value of this ratio than healthy individuals (P < 0.0001). Considering this ratio as a GC diagnostic indicator, the area under ROC curve (AUC) was 0.923[95% confidence interval (CI):0.880-0.955]. This ratio in unresectable GC was obviously lower than that in resectable GC (P = 0.0045). There was a rank correlation between this ratio and GC TNM staging (rho = -0.266, P = 0.0058), but it had no correlation with tumor size (r = 0.14, P = 0.145). Additionally, this ratio was not affected by hemolysis and repeated freeze-thaw of blood samples, and was significantly elevated after surgery(P < 0.0001). The single-stranded DNA to double-stranded DNA ratio in plasma is a stable non-invasive indicator for GC diagnosis.

4.
Int J Mol Med ; 45(6): 1783-1792, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32236608

RESUMO

Cluster of differentiation 44 (CD44) as a transmembrane glycoprotein is found to be expressed in non­small cell lung cancer (NSCLC), is significantly associated with NSLC progression, metastasis and drug resistance. This study aimed to explore whether CD44 inhibition improves the sensitivity of epidermal growth factor receptor (EGFR) wild­type NSCLC cells to cisplatin and how it affects wild­type EGFR in NSCLC cells. Small interfering RNA was used to knockdown CD44 expression in EGFR wild­type NSCLC cell line H460. Results suggested that CD44 downregulation reduced cell growth, promoted G0/G1 cell cycle arrest and induced cell apoptosis in H460 cells and these effects were evidently enhanced when in combination with cisplatin. Deactivation of EGFR signaling pathway including EGFR phosphorylation and its downstream molecules, targets ERK, AKT1 and SRC which were also observed in CD44­silenced H460 cells with or without EGF stimulation. Furthermore, the CD44 expression level was positively correlated with wild­type EGFR level in human lung adenocarcinoma tissues and CD44 inhibition significantly accelerated the degradation of EGFR, indicating that enhanced sensitivity of H460 cells to cisplatin by downregulation of CD44 might be due to EGFR degradation. This study demonstrated that suppression of CD44 deactivated EGFR signals in NSCLC cells with wild­type EGFR, thereby contributing to the inhibition of cell proliferation and the reinforcement of cisplatin sensitivity. It is suggested that downregulation of CD44 could be a novel potential therapeutic strategy for the treatment of EGFR wild­type NSCLC.

5.
Org Lett ; 22(7): 2657-2662, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32186885

RESUMO

The C-H annulation of the five-position of quinolines and acrylates to afford heterocycles is an active field of research in organic synthesis. Herein the annulation of 4-aminoquinolines with acrylates through two consecutive C-H activations catalyzed by Rh(III) is described. The reaction proceeds with high atom efficiency under mild reaction conditions, and this protocol will provide appealing strategies for the synthesis of fused quinoline heterocycles.

6.
Nanoscale Res Lett ; 14(1): 309, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31502007

RESUMO

As an important third-generation semiconductor material, the micro-deformation and removal mechanism of 6H-SiC at the atomic scale are vital for obtaining ultra-smooth and damage-free surface with atomic steps. Due to the difficulties in directly observing the surface/subsurface of nanomachining region by current experimental means, molecular dynamics method is used to study the atomic-scale details in nanomachining process, such as dislocation slip motion, phase transition, and material separation mechanism. The influence of crystallography-induced anisotropy on the slip deformation and nanometric machinability of 6H-SiC is emphatically investigated. This study contributes significantly to the understanding of micro-deformation and nanomachining process of 6H-SiC.

7.
Chin Med ; 14: 11, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30936939

RESUMO

Biofilm is a natural form of bacterial growth ubiquitously in environmental niches. The biofilm formation results in increased resistance to negative environmental influences including resistance to antibiotics and antimicrobial agents. Quorum sensing (QS) is cell-to-cell communication mechanism, which plays an important role in biofilm development and balances the environment when the bacteria density becomes high. Due to the prominent points of biofilms implicated in infectious disease and the spread of multi-drug resistance, it is urgent to discover new antibacterial agents that can regulate biofilm formation and development. Accumulated evidences demonstrated that natural products from plants had antimicrobial and chemo-preventive properties in modulation of biofilm formation in the last two decades. This review will summarize recent studies on the discovery of natural anti-biofilm agents from plants with clear-cut mechanisms or identified molecular addresses, as well as some herbs with unknown mechanisms or unidentified bioactive ingredients. We also focus on the progression of techniques on the extraction and identification of natural anti-biofilm substances. Besides, anti-biofilm therapeutics undergoing clinical trials are discussed. These newly discovered natural anti-biofilm agents are promising candidates which could provide novel strategies for biofilm-associated infections.

8.
Biochem Biophys Res Commun ; 511(4): 772-779, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30833076

RESUMO

The changes in cellular metabolism play an important role in promoting tumor progression. Recent findings suggested that the mutation of tumor suppressor gene p53 promoted lipids synthesis and mutant p53 (mutp53) was essential for regulating mevalonate pathway for cholesterol synthesis. Simvastatin, a 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitor, was found to exhibit therapeutic effects against many types of cancers including breast cancer, colon cancer, lung cancer, etc. However, the underlying mechanism of the antitumor effect of simvastatin still needs to be further investigated. Our data demonstrated that suppression of mevalonate pathway by simvastatin significantly upregulated Kruppel-like factor 2 (KLF2) and p21WAF1/CIP1 expression in mutp53 colon cancer cells SW1116 but not in p53 wild type cells HCT116. Meanwhile, we found that overexpression of KLF2 could significantly induce p21WAF1/CIP1 expression, inhibit Wnt signaling and suppress epithelial-mesenchymal transition, indicating that KL2 might mediate antitumor effect of simvastatin in SW1116 cells. Moreover, bioinformatic analysis from The Cancer Genome Atlas (TCGA) database indicated that KLF2 were positively correlated with CDKN1A (encoding p21WAF1/CIP1), both of which were downregulated in colon cancer tissue, especially in p53 mutant colon cancer tissue. The results showed that KLF2 might be a tumor suppressor gene in colon cancer, which was in accordance with our experimental data. We also found that CDKN1A expression in mutant p53 colon cancer tissue was significant decreased when compared with p53 wild type colon cancer tissue, while Wnt ligand Wnt5a exhibited the highest level in p53 mutant colon cancer tissue. These data provide strong evidences for clinical application of simvastatin in treatment of colon cancer with p53 mutation.


Assuntos
Neoplasias do Colo/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Fatores de Transcrição Kruppel-Like/genética , Sinvastatina/farmacologia , Proteína Supressora de Tumor p53/genética , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/genética , Regulação para Baixo/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Humanos , Mutação , Invasividade Neoplásica/genética , Invasividade Neoplásica/prevenção & controle , Regulação para Cima/efeitos dos fármacos
9.
Anal Bioanal Chem ; 411(4): 895-903, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30617397

RESUMO

Real-time quantitative PCR (qPCR) has been widely implemented for molecular testing, but there are still some inherent limitations that hamper its usefulness. Droplet digital PCR (ddPCR), which can provide direct, standards-free quantification, has recently received increasing attention. In our study, a comprehensive comparison of ddPCR with qPCR in relation to the quantification of PML-RARα was performed to evaluate the diagnostic potential of ddPCR. Results showed that ddPCR displayed significant concordance with qPCR in the detection of PML-RARα in clinical samples, but showed advantages over qPCR in terms of precision, limit of detection (LOD), and other basic performance parameters. A study of the feasibility of duplexing also indicated that ddPCR could simultaneously quantify the target PML-RARα and the clinical common reference gene ABL in a reaction, in contrast to qPCR. Moreover, ddPCR was more tolerant than qPCR of inhibition, and was shown to be able to quantify inhibition-prone samples. Another advantage of using ddPCR in clinical applications is that it will yield accurate results for patients with PML-RARα levels that fluctuate around the LOD of qPCR. Therefore, ddPCR is considered to have the potential to become a reliable alternative technique for quantifying PML-RARα. Graphical abstract ᅟ.


Assuntos
Leucemia Mieloide Aguda/genética , Proteínas de Fusão Oncogênica/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Primers do DNA , Sondas de DNA , Humanos , Leucemia Mieloide Aguda/diagnóstico , Limite de Detecção , Plasmídeos , Reprodutibilidade dos Testes , Temperatura
10.
Int J Biol Macromol ; 126: 1050-1055, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30615964

RESUMO

Nucleocytoplasmic transport is essential for normal cellular function that mediates cargo transport from the cytoplasm to the nucleus. However, the mechanisms of nucleocytoplasmic transport that integrate stem cell development remain largely unknown. Since it has a large population of stem cells, the planarian flatworm is an ideal system for the study of adult stem cell lineage development in vivo. Here, we focus on exportin-1, which is the most conserved nuclear export receptor. Homologs of exportin-1 have no currently known role in stem cell biology. RNA interference targeting exportin-1 caused a failure in anterior and posterior regeneration, and resulted in curly and lysis phenotypes in both intact and regenerating flatworms. During the course of exportin-1 RNAi phenotype, cell division was significantly decreased, and the expression of the epidermal cell markers (vimentin and laminB) were lost from the intact body. Additionally, the expression levels of the neoblast marker piwiA decreased. By contrast, the expression levels of the epidermal progenitor markers NB21.11e and AGAT1 increased. These results suggest that exportin-1 is required for the maintenance of the epidermal lineage in planarians. Inhibition of exportin-1 could promote the premature differentiation of neoblasts to the epidermal lineages, disrupting the proper epidermal maturation.


Assuntos
Linhagem da Célula , Epiderme/metabolismo , Carioferinas/metabolismo , Planárias/citologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Divisão Celular , Proliferação de Células , Homeostase , Carioferinas/química , Fenótipo , Filogenia , Interferência de RNA , Receptores Citoplasmáticos e Nucleares/química , Regeneração
11.
J Am Chem Soc ; 141(7): 3187-3197, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30681846

RESUMO

An operationally simple and highly selective Au/Ag bimetallic-catalyzed cross-dehydrogenative biaryl coupling between pyrazoles and fluoroarenes has been developed. With this reaction, a wide range of biheteroaryl products can be obtained in moderate to good yields with excellent functional group compatibility. The exact role of silver salts, previously overlooked in most gold-catalyzed transformations, has been carefully investigated in this biaryl coupling. Insightful experimental and theoretical studies indicate that silver acetate is the actual catalyst for C-H activation of electron-poor arenes, rather than the previously reported gold(I)-catalyzed process. An unprecedented Au/Ag dual catalysis is proposed, in which silver(I) is responsible for the activation of electron-poor fluoroarenes via a concerted metalation-deprotonation pathway, and gold(III) is responsible for the activation of electron-rich pyrazoles via an electrophilic aromatic substitution process. Kinetic studies reveal that ArFnAu(III)-mediated C-H activation of pyrazoles is most likely the rate-limiting step.

12.
Cancer Manag Res ; 10: 5825-5838, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30510451

RESUMO

Background: The dysfunction of cell apoptosis is an important event in the progression of cancer, and the growth of cancer cells is negatively regulated by cell apoptosis. In different types of cancers, inhibition of cellular apoptosis is often observed in the cancerous tissue, and increased resistance to apoptosis is a hallmark of cancer. Although previous studies have shown that 12-lipoxygenase (12-LOX)/12-hydroxyeicosatetraenoic acid (12-HETE) is activated and upregulated in different types of cancers, the consequences of 12-LOX/12-HETE upregulation and its precise roles in the survival of ovarian carcinoma cells are still unknown. Methods: MTT assays, caspase activity assays, lactate dehydrogenase (LDH) assays, and Western blot analysis were the methods used in this study. Results: In our study, we found that 12-HETE, a major metabolic product of arachidonic acid using 12-LOX catalysis, inhibited cell apoptosis in a dose-dependent manner and that the effects of 12-HETE on cell apoptosis were mediated by the integrin-linked kinase (ILK) pathway. Moreover, the downstream target of 12-HETE-activated ILK was nuclear factor kappa-B (NF-κB) in ovarian carcinoma. The inhibitory effects of 12-HETE on cell apoptosis were attenuated by the inhibition of the NF-κB pathway. Conclusion: These results indicate that 12-HETE participates in the inhibition of cell apoptosis by activating the ILK/NF-κB pathway, implying an important underlying mechanism that promotes the survival of ovarian cancer cells.

13.
Phys Chem Chem Phys ; 20(45): 28894-28902, 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30421758

RESUMO

The generalized energy-based fragmentation (GEBF) method has been extended to facilitate ab initio calculations of large supramolecular coordination complexes. For metal-containing coordination complexes, a special fragmentation scheme is proposed for GEBF calculations, in which coordinate bonds between metal ions and ligands are kept intact, and only single covalent bonds in organic ligands are cut into fragments. A simple strategy is exploited for the determination of the ground-state spin multiplicity of each metal ion so that the total spin of all metal-containing subsystems is assigned automatically. With this fragmentation scheme, the GEBF method is demonstrated to provide reliable energies, optimized geometry, nuclear magnetic resonance (NMR) properties and the infrared spectrum for a medium-sized supramolecular coordination complex, which are very consistent with those from the full-system quantum chemistry calculations. The GEBF method is then applied to two large supramolecular coordination complexes to illustrate its capability. For the trimetallic coordination complex Fe2Zn2(RuL2)2 (with 618 atoms), the calculated 1H chemical shifts from GEBF calculations with the B97-2 functional can account well for the experimental NMR spectrum. For the cage-guest complex Pd4L8(BF4-)3, the computed infrared spectrum obtained with the GEBF-M06-2X method can help assign the experimental peaks to the corresponding vibrational motions. The GEBF method combining with advanced electronic structure methods is expected to be a useful tool to understand and interpret structural and spectroscopic information of various supramolecular coordination complexes.

14.
Chem Commun (Camb) ; 54(82): 11534-11537, 2018 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-30199080

RESUMO

The decarboxylative alkylation of N-hydroxyphthalimide (NHPI) based reactive esters with olefins has been achieved via an organocatalytic strategy. Control experiments and density functional theory calculations suggest that these reactions involve a boryl-radical mediated decarboxylation pathway, which is different from the single electron transfer involved in decarboxylative alkylation reactions reported previously. This metal-free decarboxylative alkylation reaction features good functional compatibility, and broad substrate scope illustrated by the transformations of both the alkyl and aryl carboxylic acid derivatives.

15.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 30(7): 686-690, 2018 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-30045799

RESUMO

OBJECTIVE: To investigate the clinical application and effect evaluation of failure mode and effect analysis (FMEA) in the optimization of vascular recanalization in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: A total of 389 STEMI patients admitted to the emergency department of the Fifth Central Hospital in Tianjin from January 2014 to January 2015 were served as the control group, and 398 STEMI patients admitted to the chest pain center of the Fifth Central Hospital in Tianjin from January 2016 to October 2017 were served as the experimental group. In the control group, routine emergency treatment was used. At the same time, the intervention room was 24-hour prepared for emergency vascular recanalization. The experimental group used FMEA. Through the usage of FMEA, the main factors those caused the delay in revascularization treatment were determined, and the revascularization process was optimized for these influencing factors, thereby shortening the "criminal" blood vessel opening time of patients. The door-to-balloon dilatation time (D-to-B time), troponin testing time, placement time of the catheterization room, initiation of the catheterization room to balloon dilatation time, and preoperative and 1 week postoperative N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, heart function parameters [left ventricular ejection fraction (LVEF), left ventricular short axis shortening rate (FS), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD)] within 1 week, 3 months and 6 months after intervention, and the incidence of main cardiovascular adverse events within 1 month after intervention, hospital mortality, the length of hospital stay, and readmission within 1 year in the patients of two groups were recorded. RESULTS: D-to-B time (minutes: 70.6±3.6 vs. 79.4±8.7), troponin testing time (minutes: 17.1±2.3 vs. 65.2±6.5), placement time of the catheterization room (minutes: 28.9±9.8 vs. 52.3±12.2) and activation of the catheterization room to balloon expansion time (minutes: 47.3±9.3 vs. 65.1±7.2) in the experimental group were significantly shorter than those in the control group (all P < 0.01). The NT-proBNP levels at 1 week after intervention in the two groups were lower than the preoperative levels, slightly lower in the experimental group, but the difference was not statistically significant. There was no significant difference in cardiac function at 1 week and 3 months after intervention between the two groups. The LVEF and FS at 6 months after intervention in the experimental group were significantly higher than those in the control group [LVEF: 0.622±0.054 vs. 0.584±0.076, FS: (38.1±4.3)% vs. (35.4±6.2)%, both P < 0.01], and LVESD and LVEDD were decreased significantly [LVESD (mm): 31.2±3.8 vs. 34.7±4.2, LVEDD (mm): 49.2±5.3 vs. 52.4±5.6, all P < 0.01]. The length of hospital stay in the experimental group was significantly shorter than that in the control group (days: 8.3±3.2 vs. 13.2±6.8, P < 0.01), the incidence of major cardiovascular adverse events within 1 month after intervention [13.6% (54/398) vs. 19.8% (77/389)], hospital mortality [1.8% (7/398) vs. 4.9% (19/389)], and readmission rate within 1 year [9.5% (38/398) vs. 14.5% (56/389)] in the experimental group were significantly lower than those in the control group (all P < 0.05). CONCLUSIONS: The usage of FMEA to optimize the vascular recanalization procedure can shorten the emergency treatment time of STEMI patients, reduce the occurrence of adverse events, and improve the prognosis.


Assuntos
Análise do Modo e do Efeito de Falhas na Assistência à Saúde , Dor no Peito , Serviço Hospitalar de Emergência , Humanos , Infarto do Miocárdio , Prognóstico
16.
Phys Chem Chem Phys ; 20(19): 13547-13557, 2018 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29726875

RESUMO

A generalized energy-based fragmentation (GEBF) approach has been developed to facilitate ab initio calculations of the ground-state energies, structures and vibrational spectra of general ionic liquid (IL) clusters. For the selected IL clusters, the accuracy of the GEBF approach with two different fragmentation schemes (ion-pair-based fragmentation and ion-based fragmentation) is evaluated with the conventional quantum chemistry calculations. Our results demonstrate that for the selected IL clusters, the GEBF approach with the ion-pair-based fragmentation scheme can provide much more accurate descriptions than that with the ion-based fragmentation scheme. The main reason for these results is that the non-integer charge behavior of each ion (cation or anion) in IL systems may induce significant errors for the GEBF approach with the ion-based fragmentation scheme, in which every ion is assumed to have an integer charge. However, this problem can be avoided by the ion-pair-based fragmentation scheme, in which each ion pair is assumed to be electrically neutral. Our illustrative results show that the GEBF approach with a dynamic ion-pair-based fragmentation scheme, in which ion pair fragments are updated for every structure, can provide satisfactory descriptions on the ground-state energies, optimized structures, and vibrational spectra of general IL clusters. The performance of the GEBF approach is found to be almost independent of the basis sets or theoretical methods, and the computational cost of the GEBF approach scales linearly with the system size at density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2) levels. Due to its excellent parallel efficiency, the GEBF approach is expected to be a cost-effective tool for investigating the structure, vibrational spectra, as well as other properties of large IL clusters.

17.
Sci Rep ; 8(1): 3103, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29449601

RESUMO

Herein, we report the solar thermal electrochemical process (STEP) aniline oxidation in wastewater for totally solving the two key obstacles of the huge energy consumption and passivation film in the electrochemical treatment. The process, fully driven by solar energy without input of any other energies, sustainably serves as an efficient thermoelectrochemical oxidation of aniline by the control of the thermochemical and electrochemical coordination. The thermocoupled electrochemical oxidation of aniline achieved a fast rate and high efficiency for the full minimization of aniline to CO2 with the stability of the electrode and without formation of polyaniline (PAN) passivation film. A clear mechanism of aniline oxidation indicated a switching of the reactive pathway by the STEP process. Due to the coupling of solar thermochemistry and electrochemistry, the electrochemical current remained stable, significantly improving the oxidation efficiency and mineralization rate by apparently decreasing the electrolytic potential when applied with high temperature. The oxidation rate of aniline and chemical oxygen demand (COD) removal rate could be lifted up to 2.03 and 2.47 times magnification compared to conventional electrolysis, respectively. We demonstrate that solar-driven STEP processes are capable of completely mineralizing aniline with high utilization of solar energy. STEP aniline oxidation can be utilized as a green, sustainable water treatment.

18.
Sci Rep ; 8(1): 1747, 2018 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-29379132

RESUMO

Here, we report a novel magnetic resonance imaging (MRI)/fluorescence bimodal amplification platform for the detection of glutathione (GSH) on the basis of redoxable manganese dioxide (MnO2) nanosheets, which can be readily applied as a DNA nanocarrier, fluorescence quencher, and intracellular GSH-activated MRI contrast agent. The binding of aptamers that absorbed on the MnO2 nanosheets to their target can facilitating the endocytosis of target-nanoprobes. Once endocytosed, the MnO2 nanosheets can react with cellular GSH, resulting in the disintegration of nanosheets to generate plenty of Mn2+ ions for MRI and releases the primers which were adsorbed on the MnO2 nanosheets. Then the rolling circle amplification (RCA) reaction was initiated to amplify the fluorescence signal. In addition, after treatment with GSH, the MnO2 nanosheets were reduced and then most of the fluorescence was recovered. Therefore, this MnO2 nanoprobe exhibits excellent selectivity, suggesting a potential detection platform for analyzing the glutathione level in cells.


Assuntos
Aptâmeros de Nucleotídeos/administração & dosagem , Meios de Contraste/administração & dosagem , Glutationa/análise , Imagem por Ressonância Magnética/métodos , Compostos de Manganês/administração & dosagem , Nanoestruturas/administração & dosagem , Imagem Óptica/métodos , Óxidos/administração & dosagem , Aptâmeros de Nucleotídeos/metabolismo , Linhagem Celular Tumoral , Meios de Contraste/metabolismo , Endocitose , Humanos , Compostos de Manganês/metabolismo , Neoplasias/diagnóstico , Neoplasias/patologia , Óxidos/metabolismo
19.
Mol Med Rep ; 16(5): 7267-7276, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28944870

RESUMO

Integrin­linked kinase (ILK) is overexpressed in ovarian cancer (OC), and ILK gene silencing results in apoptosis in OC cells. In the present study, the mechanism by which ILK induces apoptosis was explored from the perspective of microRNA (miRNA) expression. Alterations in the global miRNA expression profile were detected using a miRNA microarray after OC cells were transduced with an ILK small hairpin RNA lentivirus. ILK silencing led to a significant upregulation of 14 miRNAs by at least 1.5­fold. These findings were validated by reverse transcription­quantitative polymerase chain reaction. A pathway analysis of experimentally validated target genes revealed the inhibition of multiple cancer­associated signaling pathways and the wnt signaling pathway. Compared with cells transfected with scrambled RNA, the ILK­silenced cells had remarkably lower expression of wnt ligands (wnt3a, wnt4 and wnt5a) and downstream ß­catenin. ILK silencing led to apoptosis of OC cells and impaired the migratory ability. Taken together, the present results suggested that miRNA­mediated wnt pathway alterations are involved in the anti­apoptotic role of ILK in OC. It was also indicated that ILK silencing reduced the ability of OC cells to adhere to fibronectin, which may lead to unstable focal contact. Consistently, the phosphorylation levels of focal adhesion kinase and RAC­α serine/threonine protein kinase were downregulated. The present work demonstrated the first global miRNA expression profile of OC cells when ILK was inhibited, and this expression profile may provide a basis for the development of biomarkers and therapeutic targets for OC.


Assuntos
MicroRNAs/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Apoptose , Caspase 3/metabolismo , Adesão Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Humanos , Lentivirus/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fosforilação , Plasmídeos/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Regulação para Cima
20.
J Chem Theory Comput ; 13(6): 2696-2704, 2017 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-28478670

RESUMO

The generalized energy-based fragmentation (GEBF) method has been applied to investigate relative energies of large water clusters (H2O)n (n = 32, 64) with the coupled-cluster singles and doubles with noniterative triple excitations (CCSD(T)) and second-order Møller-Plesset perturbation theory (MP2) at the complete basis set (CBS) limit. Here large water clusters are chosen to be representative structures sampled from molecular dynamics (MD) simulations of liquid water. Our calculations show that the GEBF method is capable of providing highly accurate relative energies for these water clusters in a cost-effective way. We demonstrate that the relative energies from GEBF-MP2/CBS are in excellent agreement with those from GEBF-CCSD(T)/CBS for these water clusters. With the GEBF-CCSD(T)/CBS relative energies as the benchmark results, we have assessed the performance of several theoretical methods widely used for ab initio MD simulations of liquids and aqueous solutions. These methods include density functional theory (DFT) with a number of different functionals, MP2, and density functional tight-binding (the third generation, DFTB3 in short). We find that MP2/aug-cc-pVDZ and several DFT methods (such as LC-ωPBE-D3 and ωB97XD) with the aug-cc-pVTZ basis set can provide satisfactory descriptions for these water clusters. Some widely used functionals (such as B3LYP, PBE0) and DFTB3 are not accurate enough for describing the relative energies of large water clusters. Although the basis set dependence of DFT is less than that of ab initio electron correlation methods, we recommend the combination of a few best functionals and large basis sets (at least aug-cc-pVTZ) in theoretical studies on water clusters or aqueous solutions.

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