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1.
Aging (Albany NY) ; 122020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33031060

RESUMO

In this retrospective study we assessed the efficacy and safety of tocilizumab in patients with critical or severe coronavirus disease 2019 (COVID-19). We enrolled 181 patients admitted to Huoshenshan Hospital (Wuhan, China) with confirmed COVID-19 between January 2020 and February 2020. Ninety-two patients were treated with tocilizumab, and 89 patients were treated conventionally. We analyzed the clinical manifestations, changes in CT scan images, and laboratory tests before and after tocilizumab treatment, and compared these results with the conventionally treated group. A significant reduction in the level of C-reactive protein was observed 1 week after tocilizumab administration. In some cases this meant the end of the IL-6-related cytokine storm. In addition, tocilizumab relieved fever, cough, and shortness of breath with no reported adverse drug reactions. These findings suggest tocilizumab improves clinical outcomes and is effective for treatment of patients with critical or severe COVID-19. However, future clinical trials are needed to better understand the impact of tocilizumab interference with IL-6 and provide a therapeutic strategy for treatment of COVID-19.

2.
Endosc Ultrasound ; 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32952130

RESUMO

For a definitive diagnosis of fine-needle aspiration (FNA)/biopsy, one of the reliable techniques to determine the adequacy and accuracy rapid on-site evaluation (ROSE) of cytological samples is preferable. Because of the lack of trained pathologists, alternatives have to be explored. This study is primarily conducted to determine the diagnostic sensitivity and specificity of full-field optical coherence tomography (FF-OCT) and secondarily to evaluate the possibility of FF-OCT differentiating different types of pancreatic diseases. The diagnostic coherence of FF-OCT by a trained assistant (endoscopist) and trained pathologist is also compared. This is a single-center, prospective, observation trial. Eighty patients would be enrolled in the study. The tissue samples acquired by endoscopic ultrasound fine-needle biopsy (EUS-FNB) would be imaged by the FF-OCT system, interpreted by a trained endoscopist and a pathologist. The results of the image interpretation would be verified with histological findings. This study determines the diagnostic capability of FF-OCT as a ROSE technique while performing EUS-FNB, and whether endoscopists can implement the assessment.

3.
Chem Commun (Camb) ; 56(73): 10767, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32930252

RESUMO

Correction for 'Bioinspired hydrogel-based nanofluidic ionic diodes: nano-confined network tuning and ion transport regulation' by Congcong Zhu et al., Chem. Commun., 2020, 56, 8123-8126, DOI: 10.1039/D0CC01313G.

4.
Surg Endosc ; 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32748263

RESUMO

BACKGROUND: Endoscopic submucosal dissection (ESD) is accepted as a standard therapeutic technique for superficial esophageal neoplasms (SENs). However, esophageal refractory stricture is a serious adverse event secondary to extensive ESD (≥ 3/4 of the luminal circumference). This retrospective study aimed to investigate the risk factors for refractory postoperative stricture after extensive ESD. METHODS: The data of patients who underwent esophageal ESD at the Endoscopy Center of Changhai Hospital were reviewed between January 2011 and September 2019. Risk factors for postoperative refractory stricture [≥ 6 sessions of endoscopic balloon dilation (EBD)] after extensive ESD were then identified using univariate analysis and multivariate logistic regression analysis. RESULTS: A total of 69 SENs in 67 patients treated by extensive ESD were enrolled in this study. The refractory stricture incidence was 62% (43/69). Significant differences between non-refractory stricture group and refractory stricture group were observed in depth of infiltration (m1or m2/m3 or sm1:20/6 vs. 17/26, P = 0.003), longitudinal resection length (< 50 mm/ ≥ 50 mm:19/7 vs. 10/33, P < 0.001), circumferential range (3/4~ < 1/1:20/6 vs. 19/24, P = 0.008), muscular injury (NO/YES:18/8 vs. 19/24, P = 0.043), and clip number (≤ 5/ > 5:15/11 vs. 12/31, P = 0.014). Multivariate analysis revealed that longitudinal resection length ≥ 50 mm (odds ratio [OR] 11.099, 95% confidence interval [CI] 2.620-47.019), depth of infiltration above m2 (OR 5.716, 95%CI 1.324-24.672) and muscular injury happened (OR 4.431, 95%CI 1.052-18.659) were independent risk factors for refractory stricture. In addition, the EBD sessions for treatment of refractory stricture was related to longitudinal resection length (relation coefficient γ = 0.528; P <0.05). CONCLUSIONS: The longitudinal resection length, depth of tumor infiltration and muscular injury are the reliable risk factors for esophageal refractory stricture after extensive ESD.

5.
ACS Nano ; 14(8): 9701-9710, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32687698

RESUMO

As an approach to harvesting sustainable energy from ambient conditions, the osmotic energy between river water and seawater contributes to solving global issues such as the energy shortage and environmental pollution. Current attempts based on a reverse electrodialysis technique are limited mainly due to the economically unviable power density and inadequate mass transportation of membrane materials. Here, we demonstrate a benign strategy for designing a multilayer graphene oxide-silk nanofiber-graphene oxide biomimetic nacre-like sandwich as an osmotic power generator. Enhanced interfacial bonding endows the composite membranes with long-term stability in saline, and meanwhile, the two-dimensional nanofluidic channel configuration also reduces the ion transport resistance and provides large storage spaces for ions. Thus, the output power density of the proposed membrane-based generator achieves a value of up to 5.07 W m-2 by mixing seawater and river water. Furthermore, we experimentally and theoretically demonstrate that the thermal-field drives the increased output power density due to the advances in ionic movement range and activity of electrode reaction, showing the promise of strengthened thermo-osmotic energy conversion.

6.
Chem Commun (Camb) ; 56(58): 8123-8126, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32691786

RESUMO

Biological ion channel-based mass transport and signal transduction play a crucial role in physiological activities, and biomimetic nanochannels in aqueous solutions for ion transport regulation have been extensively studied. Few studies on non-aqueous systems, gel-based nanochannels, mainly focus on the charged gel network or embedded electrolytes. However, the basic issue of how a nanoscale gel network affects the ion transport in nanochannels has been neglected. Here, we demonstrate a non-aqueous biomimetic nanochannel system by employing the agarose hydrogel in conical nanochannels. To tune the hydrogel network by adjusting the gel concentration, the ion transport behavior in gel-based nanochannels is systemically investigated. The experimental results show that the ion transport behaviors in gel-nanochannels with 2% gel present similar ion selectivity and rectification performance to the aqueous system, indicating fast investigation of gel-based systems with the knowledge of the extensively studied aqueous systems. Furthermore, a gel-based solid-state diode and logic circuits were fabricated.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32692569

RESUMO

To mimic and use the functions of the ion transport system that are central to biological processes, bioinspired ion-selective membranes are developed and show great potential in a variety of fields. However, the practical applications of them are now limited due to low pore density, low conductivity, or scale-up difficulty. Herein, we demonstrate a 2-hydroxyethyl methacrylate phosphate (HEMAP) hydrogel membrane with 3D interconnected nanopores and space charged through simple photopolymerization. The HEMAP hydrogel membrane exhibits high conductance and outstanding ion selectivity, and the membrane-based osmotic power generator shows the excellent output power density up to 5.38 W/m2. Both experimentally and theoretically, the 3D interconnected structure is revealed to play a key role in enhancing charge-governed ion transport and energy conversion. This work highlights the advantages of 3D interconnected nanopores in ion diffusion and shows the potential of our designed hydrogel membrane in osmotic energy conversion, water desalination, and sensors.

8.
Proc Natl Acad Sci U S A ; 117(29): 16743-16748, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32611809

RESUMO

Mammalian nervous systems, as natural ionic circuitries, stand out in environmental perception and sophisticated information transmission, relying on protein ionic channels and additional necessary structures. Prosperously emerged ionic regulated biomimetic nanochannels exhibit great potentialities in various application scenarios, especially signal transduction. Most reported direct current systems possess deficiencies in informational density and variability, which are superiorities of alternating current (AC) systems and necessities in bioinspired nervous signal transmission. Here, inspired by myelinated saltatory conduction, alternating electrostatic potential controlled nanofluidics are constructed with a noncontact application pattern and MXene nanosheets. Under time-variant external stimuli, ions confined in the interlaminar space obtain the capability of carriers for the AC ionic circuit. The transmitted information is accessible from typical sine to a frequency-modulated binary signal. This work demonstrates the potentiality of the bioinspired nervous signal transmission between electronics and ionic nanofluidics, which might push one step forward to the avenue of AC ionics.


Assuntos
Potenciais de Ação , Materiais Biomiméticos/química , Condutividade Elétrica , Microfluídica/métodos , Modelos Neurológicos , Nanoestruturas/química , Dimetilpolisiloxanos/química , Equipamentos e Provisões Elétricas , Transporte de Íons , Microfluídica/instrumentação
9.
Artigo em Inglês | MEDLINE | ID: mdl-32578316

RESUMO

Osmotic energy, obtained through different concentrations of salt solutions, is recognized as a form of a sustainable energy source. In the past years, membranes derived from asymmetric aromatic compounds have attracted attention because of their low cost and high performance in osmotic energy conversion. The membrane formation process, charging state, functional groups, membrane thickness, and the ion-exchange capacity of the membrane could affect the power generation performance. Among asymmetric membranes, a bipolar membrane could largely promote the ion transport. Here, two polymers with the same poly(ether sulfone) main chain but opposite charges were synthesized to prepare bipolar membranes by a nonsolvent-induced phase separation (NIPS) and spin-coating (SC) method. The maximum power density of the bipolar membrane reaches about 6.2 W m-2 under a 50-fold salinity gradient, and this result can serve as a reference for the design of bipolar membranes for osmotic energy conversion systems.

10.
Nano Lett ; 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32242672

RESUMO

Chemical potential energy harvesting from the concentration gradient has been largely improved recently due to the development of nanofluidic energy conversion systems. However, the reported systems mainly focus on improving the membrane's performance but neglect the forms of concentration gradient. Here, we demonstrate the chemical reaction assisted chemical-potential-driven directional ion transport through layered titanium carbides membranes for energy harvesting. The MXene membrane with negatively charged nanochannels shows excellent cation selectivity and could reach 1.1 W/m2 for a 500-fold salinity gradient. By adopting the traditional neutralization reaction, HCl/KOH as the acid-base pair (ABP), the power density can reach 7.89 W/m2 with 1 M ABP due to the maintained transmembrane proton gradient. Besides, the membrane's excellent acid-base stability renders the power density stable for ∼192 h without obvious damping. This work provides new inspiration for industrial waste treatment issues and would be worth exploring its potential applications in extreme environments.

11.
Analyst ; 145(8): 3029-3037, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32134064

RESUMO

We herein report a simple anthraquinone-imidazole-based compound, 2-(furan-2-yl)-1H-anthra[1,2-d]imidazole-6,11-dione (FAI), as an effective colorimetric and fluorometric Ag+ sensor. In 1,4-dioxane/water (3 : 7, v/v, pH 7.4), FAI could selectively recognize and detect Ag+ ions via significant fluorescence quenching at 606 nm, accompanied by a rapid color change from yellow to orange. FAI exhibited high sensitivity to Ag+ in a linear dynamic range from 0.8-32 µM, with the detection limit of 66 nM. Job's plot analysis and HRMS studies supported the formation of the FAI-Ag+ complex in a ratio of 1 : 1. The in situ generated FAI-Ag+ complex was further utilized as a reversible sensor to detect biothiols (Cys, Hcy, GSH) through a decomplexation reaction, with the detection limit of 89 nM, 174 nM and 208 nM for Cys, Hcy and GSH, respectively. In addition, FAI with low cytotoxicity was efficient in monitoring Ag+ ions and biothiols in living human hepatoma cells SMMC-7721 as demonstrated by fluorescence microscopy imaging.

12.
Environ Sci Pollut Res Int ; 27(13): 15198-15210, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32067174

RESUMO

The present study employs a novel technique combining Fenton reaction with sinusoidal alternating current electrocoagulation (FSACEC), which is used to remove chemical oxygen demand (COD) in the simulated electroplating wastewater with the advantages of low energy consumption and small sludge. Fe2+, produced from the dissolution of Fe anodes in the FSACEC process, reacts with H2O2 to generate more ·OH and forms the iron hydroxide precipitates. The higher efficiency of COD removal is achieved through both effects of the oxidation reaction and the physical adsorption. The scanning electron microscopy (SEM) analysis shows that the particle size of FSACEC products is between 30 and 40 nm, which is less than the Fenton-direct current electrocoagulation products. The effect of the current concentration (IV), initial pH (pH0), and the addition of hydrogen peroxide (30% H2O2) was discussed on the optimal process parameters. In pH0 2.0 wastewater, applying current concentration of 1 A dm-3, the addition 20 cm3 dm-3 30% H2O2, the removal efficiency of COD reached 94.21% and the residual COD in wastewater was only 60 mg dm-3 after 90 min of operation. In order to investigate the maximum removal efficiency in a certain period of operation, the larger current concentration is applied to remove COD. The FSACEC process exhibits the higher removal COD efficiency and wider operation range of pH0 than the single Fenton technique. The FSACEC process is in accordance with the kinetic law of the pseudo-second-order kinetic adsorption model.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Análise da Demanda Biológica de Oxigênio , Eletrocoagulação , Galvanoplastia , Peróxido de Hidrogênio , Resíduos Industriais/análise , Eliminação de Resíduos Líquidos
13.
Emerg Infect Dis ; 26(3): 437-445, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32091361

RESUMO

CaliciNet China, a network of provincial, county, and city laboratories coordinated by the Chinese Centers for Disease Control and Prevention, was launched in October 2016 to monitor the epidemiology and genotype distribution of norovirus outbreaks in China. During October 2016-September 2018, a total of 556 norovirus outbreaks were reported, and positive fecal samples from 470 (84.5%) outbreaks were genotyped. Most of these outbreaks were associated with person-to-person transmission (95.1%), occurred in childcare centers or schools (78.2%), and were reported during November-March of each year (63.5%). During the 2-year study period, 81.2% of all norovirus outbreaks were typed as GII.2[P16]. In China, most norovirus outbreaks are reported by childcare centers or schools; GII.2[P16] is the predominant genotype. Ongoing surveillance by CaliciNet China will provide information about the evolving norovirus genotype distribution and outbreak characteristics important for the development of effective interventions, including vaccines.

14.
Mol Oncol ; 14(4): 865-881, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31981446

RESUMO

Although circulating tumor cells (CTCs) have shown promise as potential biomarkers for diagnostic and prognostic assessment in gastric cancer (GC), determining the predictive and prognostic value of programmed death-ligand 1 (PD-L1)-positive CTCs in patients with GC is a challenge. Here, we identified that the expression of total vimentin (VIM) protein was positively correlated with PD-L1 and inhibited CD8+ T-cell activation in patients with GC according to bioinformatics analysis. Notably, coexpression of PD-L1 and cell-surface VIM (CSV) was detected by immunofluorescence and immunohistochemistry assay in locally advanced GC tumor specimens and metastatic lymph nodes. Likewise, CSV expression level was significantly decreased after transiently knocking down PD-L1 in GC cell lines. Based on our established CTC detection platform, CTCs were isolated from peripheral blood samples collected from 70 patients (38 resectable and 32 unresectable) with GC using magnetic positive selection and a CSV-specific monoclonal antibody, 84-1. CSV+ PD-L1+ CTCs were observed in 50 of 70 (71%) GC patient samples, ranging from 0 to 261 mL-1 . A higher number of CSV+ PD-L1+ CTCs were significantly associated with a short survival duration and poor therapeutic response. This study demonstrated that detection of PD-L1+ CTCs using a CSV-enrichment method has promising value as a clinically relevant prognostic marker for GC.

15.
ACS Appl Mater Interfaces ; 12(3): 3854-3861, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31874024

RESUMO

Radioactive contamination is a highly concerning global environmental issue along with the development of the nuclear industry. On account of sophisticated operations and high cost of instrument detection methods, numerous efforts have been focused on rapid and simple detection of pollution elements and uranium is the most common one. It is an enormous challenge to push the limit of determination as low as possible while carrying out ultrasensitive detection. Here, we report an intelligent platform based on functionalized solid nanochannels to monitor ultratrace uranyl ions. The platform has a detection limit of 1 fM, which is far below the value that traditional instrumental methods can reach. What is more, the system also exhibits uranyl removal property. The mesenchymal stem cells cultivated in media containing uranyl can achieve excellent viability in the presence of the membranes. This work provides a new choice for handling global radioactive contamination of water.


Assuntos
Técnicas de Química Analítica/métodos , Urânio/análise , Poluentes Radioativos da Água/análise , Adsorção , Técnicas de Química Analítica/instrumentação , Concentração de Íons de Hidrogênio , Água do Mar/análise , Contaminação Radioativa da Água
16.
ACS Appl Mater Interfaces ; 11(50): 47003-47007, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31746190

RESUMO

Flexible perovskite solar cells (F-PSCs) have been developing fast with the power conversion efficiency (PCE) exceeding 19%. However, aiming at the high-efficiency F-PSCs, to get a desired perovskite morphology before and after glass-supportive device transfer is still a challenge. Herein, we thoroughly investigated the effect of adhesive materials of substrates on the perovskite film and the solar cell performance and developed a nondestructive F-PSC transfer method by introducing a double-side tape/protective film/epoxy binder. This nondestructive transfer strategy leads to a uniform morphology of perovskites, even after transfer process, yielding an enhanced PCE up to 16.55%.

17.
Chin J Integr Med ; 25(9): 643-647, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31650484

RESUMO

Pre-rheumatoid arthritis is the inevitable phase before the actual onset of rheumatoid arthritis and has the crucial clinical significance of early controlling and preventing disease progression. Full understanding, from both Western medicine (WM) and Chinese medicine (CM), could offer new ideas for decision making in clinical and mechanism research. This paper reviews the novel studies of WM and CM to discuss the advantages and potential mechanisms working behind.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Pesquisa Biomédica , Medicina Tradicional Chinesa , Animais , Artrite Reumatoide/prevenção & controle , Humanos
18.
PLoS Biol ; 17(10): e3000498, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31613879

RESUMO

During gastrulation, the pluripotent epiblast self-organizes into the 3 germ layers-endoderm, mesoderm and ectoderm, which eventually form the entire embryo. Decades of research in the mouse embryo have revealed that a signaling cascade involving the Bone Morphogenic Protein (BMP), WNT, and NODAL pathways is necessary for gastrulation. In vivo, WNT and NODAL ligands are expressed near the site of gastrulation in the posterior of the embryo, and knockout of these ligands leads to a failure to gastrulate. These data have led to the prevailing view that a signaling gradient in WNT and NODAL underlies patterning during gastrulation; however, the activities of these pathways in space and time have never been directly observed. In this study, we quantify BMP, WNT, and NODAL signaling dynamics in an in vitro model of human gastrulation. Our data suggest that BMP signaling initiates waves of WNT and NODAL signaling activity that move toward the colony center at a constant rate. Using a simple mathematical model, we show that this wave-like behavior is inconsistent with a reaction-diffusion-based Turing system, indicating that there is no stable signaling gradient of WNT/NODAL. Instead, the final signaling state is homogeneous, and spatial differences arise only from boundary effects. We further show that the durations of WNT and NODAL signaling control mesoderm differentiation, while the duration of BMP signaling controls differentiation of CDX2-positive extra-embryonic cells. The identity of these extra-embryonic cells has been controversial, and we use RNA sequencing (RNA-seq) to obtain their transcriptomes and show that they closely resemble human trophoblast cells in vivo. The domain of BMP signaling is identical to the domain of differentiation of these trophoblast-like cells; however, neither WNT nor NODAL forms a spatial pattern that maps directly to the mesodermal region, suggesting that mesoderm differentiation is controlled dynamically by the combinatorial effect of multiple signals. We synthesize our data into a mathematical model that accurately recapitulates signaling dynamics and predicts cell fate patterning upon chemical and physical perturbations. Taken together, our study shows that the dynamics of signaling events in the BMP, WNT, and NODAL cascade in the absence of a stable signaling gradient control fate patterning of human gastruloids.


Assuntos
Proteína Morfogenética Óssea 4/genética , Gastrulação/genética , Mesoderma/metabolismo , Proteína Nodal/genética , Transdução de Sinais , Proteínas Wnt/genética , Benzotiazóis/farmacologia , Padronização Corporal/efeitos dos fármacos , Padronização Corporal/genética , Proteína Morfogenética Óssea 4/metabolismo , Proteína Morfogenética Óssea 4/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Gástrula/citologia , Gástrula/efeitos dos fármacos , Gástrula/metabolismo , Gastrulação/efeitos dos fármacos , Regulação da Expressão Gênica , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/efeitos dos fármacos , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Mesoderma/citologia , Mesoderma/efeitos dos fármacos , Modelos Biológicos , Modelos Estatísticos , Proteína Nodal/deficiência , Organoides/citologia , Organoides/efeitos dos fármacos , Organoides/metabolismo , Proteínas Wnt/metabolismo
19.
Oncol Rep ; 42(5): 1893-1903, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31485631

RESUMO

Cancer requires aerobic glycolysis to supply the energy required for proliferation. Existing evidence has revealed that blocking glycolysis results in apoptosis of cancer cells. Tanshinone IIA (Tan IIA) is a diterpenoid naphthoquinone found in traditional Chinese medicine, Danshen (Salvia sp.). Tan IIA exhibits potential anticancer activity. However, its effect on cell viability of human cervical cancer cells and its mechanism are unknown. The aim of the present study was to determine the effect of Tan IIA on proliferation and glucose metabolism in cervical cancer cells. Cell viability was measured by MTT assay, apoptosis was determined using flow cytometry and glucose uptake, lactate production, and adenosine triphosphate content were measured to assess glucose metabolism. The expression of apoptosis­associated proteins was detected by western blotting and the antitumor activity of Tan IIA in vivo was evaluated in cervical carcinoma­bearing mice. The results revealed Tan IIA treatment resulted in a considerable reduction in the viability of SiHa cells. Tan IIA decreased the expression of HPV oncogenes E6 and E7, induced apoptosis and also decreased glycolysis by suppressing the activity of the intracellular AKT/mTOR and HIF­1α. In vivo, treatment with Tan IIA resulted in a 72.7% reduction in tumor volume. The present study highlights the potential therapeutic value of Tan IIA, which functions by inducing apoptosis and may be associated with inhibition of glycolysis.


Assuntos
Abietanos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Glucose/metabolismo , Neoplasias do Colo do Útero/tratamento farmacológico , Abietanos/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Células HeLa , Humanos , Ácido Láctico/metabolismo , Camundongos , Transdução de Sinais/efeitos dos fármacos , Resultado do Tratamento , Neoplasias do Colo do Útero/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
20.
J Mater Chem B ; 7(30): 4620-4629, 2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31364679

RESUMO

A novel probe, 3-benzyl-2-(N-ethylcarbazole-3-vinyl)-benzothiazolium bromide (L), was synthesized and utilized for the specific detection of cyanide ions in neutral aqueous solution (HEPES buffer, pH 7.4). This probe displays a fast response through visible colorimetric and fluorogenic changes toward CN-, allowing for ratiometric sensing of cyanide in aqueous media. The ratiometric response is due to the breaking of the extensive π-conjugation and the intramolecular charge transfer (ICT) by the nucleophilic conjugation addition of cyanide to L, which is ascertained by NMR and ESI-MS analysis as well as density functional theory (DFT) calculations. The detection limit of CN- (3.39 × 10-7 M) is well below the limit recommended in the World Health Organization (WHO) guidelines for drinking water. Moreover, fluorescence co-localization studies demonstrate that L is a specific mitochondria-targeting fluorescent probe. As far as we are aware, compound L is the first mitochondria-targeting probe for cyanide detection and can be used for sensing CN- in living cells with dual channel ratiometric fluorescence imaging.

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