Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Environ Manage ; 351: 119825, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38169253

RESUMO

Cities occupy a central position in addressing climate change and promoting sustainable regional development. Synergistic control of urban gas emissions at the city level is one of the main issues typically explored. The confounding effect and the interactions between the urban indicators of population and area have been ignored in previous studies. In this study, we examined the spatial distribution characteristics and synergy between greenhouse gases (CO2) and air pollutants (SO2 and NOX) using spatial population and gas emission data. By upgrading the city clustering algorithm (CCA), we established a method for defining active areas of gas emissions (spatial element-coupled clustering, SECC) and identified active areas of gas emissions in China. In this study, we created a research framework that can simultaneously consider the effects of population and area, as well as the possible interactions between these indicators in active areas. The superlinear scaling relationship between the above three gases was revealed at the active zone level, and the existence of synergy between the emission patterns of the three gases was confirmed. Via further model application, we measured the synergistic efficiency of the three gases. It was found that for every 1% increase in SO2 and NOX in an active zone, CO2 increases by 0.86%. In this study, we explored a new perspective and approach to explain the synergy between greenhouse gases and air pollutants. This is essential to promote national competition among cities to achieve synergistic control of CO2 and local air pollutants.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Gases de Efeito Estufa , Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Poluição do Ar/análise , China , Gases/análise , Monitoramento Ambiental/métodos , Material Particulado/análise
2.
Anal Chem ; 94(34): 11813-11820, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35925790

RESUMO

Simultaneous monitoring of the ATP levels at various sites of a single cell is crucial for revealing the ATP-related processes and diseases. In this work, we rationally fabricated single nanowire-based fluorescence biosensors, by which the ATP levels of the cytoplasm and nucleus in a single cell can be simultaneously monitored with a high spatial resolution. Utilizing the as-fabricated single nanowire biosensor, we demonstrated that the ATP levels of the cytoplasm were around 20-30% lower than that of the nucleus in both L929 and HeLa cells. Observing the ATP fluctuation of the cytoplasm and nucleus of the L929 and HeLa cells stimulated by Ca2+, oligomycin, or under cisplatin-induced apoptosis, we found that the ATP levels at two cellular sites exhibited discriminative changes, revealing the different mechanisms of the ATP at these two cellular sites in response to the stimulations.


Assuntos
Técnicas Biossensoriais , Nanofios , Trifosfato de Adenosina , Citoplasma , Células HeLa , Humanos
3.
Opt Express ; 30(24): 43590-43600, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36523054

RESUMO

The unique performances of Epsilon-near-zero (ENZ) materials allow them to play a crucial role in many optoelectronic devices and have spawned a wide range of inventive uses. In this paper, we found that the modified PEDOT:PSS film formed with a kind of so-called "Metastable liquid-liquid Contact (MLLC)" solution treatment method can achieve a wide tuning of ENZ wavelength from 1270 nm to 1550 nm in the near-infrared region. We further analyzed the variation trend of imaginary permittivity for these samples with different ENZ wavelengths. The Berreman mode was successfully excited by a simple structural design to realize a tunable polarization absorber.

4.
Fish Shellfish Immunol ; 127: 256-263, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35750117

RESUMO

Aeromonas hydrophila was a common bacterial pathogen in aquaculture resulting in considerable losses to the striped catfish aquaculture industry. As an emergent antimicrobial peptide (AMP), NK-lysin (NKL) had activity against various microorganisms. However, the antibacterial activity of NKL from striped catfish (Pangasianodon hypophthalmus) both in vitro and vivo remains unclear. In this study, the cDNA sequence of P. hypophthalmus NK-lysin gene (PhNK-lysin) was cloned and characterized. The amino acid sequence of PhNK-lysin contains a signal peptide sequence of 17 amino acid (aa) residues and a mature peptide composed of 130 aa. The saposin B domain of mature peptide comprised six conserved cysteines forming three putative disulfide bonds. Phylogenetic analysis revealed that the PhNK-lysin was most closely related to that of the channel catfish (Ictalurus punctatus) NK-lysin. The transcriptional levels of the PhNK-lysin were significantly upregulated in response to A. hydrophila infection in various tissues including heart, liver, spleen, head kidney, trunk kidney and gill. The synthetic PhNK-lysin-derived peptide consisting of 38aa showed antibacterial activity against Vibrio harveii, Aeromonas hydrophila and Escherichia coli. The MIC for V. harveii, A. hydrophila and E. coli were 15.625 µM, 250 µM and 31.25 µM respectively. Besides, the synthetic PhNK-lysin decreased the bacterial load of liver and trunk kidney in vivo as well as increased the survival rate of A. hydrophila infected striped catfish. Hence, these data suggest that PhNK-lysin had antimicrobial effect and protects the host from pathogenic infection.


Assuntos
Peixes-Gato , Doenças dos Peixes , Ictaluridae , Aeromonas hydrophila , Animais , Antibacterianos/farmacologia , Peixes-Gato/genética , Escherichia coli , Doenças dos Peixes/microbiologia , Ictaluridae/genética , Filogenia , Proteolipídeos
5.
Beilstein J Org Chem ; 18: 1249-1255, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36158175

RESUMO

The electrochemical preparation of 2-aminothiazoles has been achieved by the reaction of active methylene ketones with thioureas assisted by ᴅʟ-alanine using NH4I as a redox mediator. The electrochemical protocol proceeds in an undivided cell equipped with graphite plate electrodes under constant current conditions. Various active methylene ketones, including ß-keto ester, ß-keto amide, ß-keto nitrile, ß-keto sulfone and 1,3-diketones, can be converted to the corresponding 2-aminothiazoles. Mechanistically, the in situ generated α-iodoketone was proposed to be the key active species.

6.
J Cell Physiol ; 236(7): 5278-5292, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33452687

RESUMO

Osteoarthritis (OA) is the most common joint disease. The surface of joint cartilage is a defensive and first affected structure of articular cartilage (AC) during the pathogenesis of OA. Alk5 signaling is critical for maintaining AC homeostasis, however, the role and underlying mechanism for the involvement of Alk5 signaling in the phenotypes of articular cartilage stem cells (ACSCs) at the surface of AC is still unclear. The role of Alk5 in OA development was explored using an ACSCs-specific Alk5-deficient (cKO) mouse model. Alterations in cartilage structure were evaluated histologically. Senescence was detected by SA-ß-gal, while reactive oxygen species (ROS), MitoTracker, and LysoTracker staining were used to detect changes related to senescence. In addition, mice were injected intra-articularly with ganciclovir to limit the detrimental roles of senescent cells (SnCs). Alk5 cKO mice showed a decreased number of the slow-cell cycle cells and less lubricant secretion at the surface accompanied with drastically accelerated cartilage degeneration under ageing and surgically induced OA conditions. Further studies showed that Alk5 deficient ACSCs exhibited senescence-like manifestations including decreased proliferation and differentiation, more SA-ß-gal-positive cells and ROS production, as well as significantly swollen mitochondria and lysosome breakdown. We further found that local limitation of the detrimental roles of SnCs can attenuate the development of posttraumatic OA. Taken together, our findings suggest that Alk5 signaling acts as an important regulator of the SnCs in the superficial layer during AC maintenance and OA initiation.


Assuntos
Cartilagem Articular/metabolismo , Senescência Celular/fisiologia , Osteoartrite/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Células-Tronco/metabolismo , Animais , Artrite Experimental/metabolismo , Artrite Experimental/patologia , Cartilagem Articular/patologia , Camundongos , Camundongos Knockout , Osteoartrite/patologia , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/metabolismo
7.
Anal Chem ; 93(45): 15072-15079, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34617743

RESUMO

Detecting the temperature of intracellular mitochondria with high sensitivity and stability is crucial to understanding the cellular metabolism and revealing the processes of mitochondria-related physiology. In this paper, employing the long fluorescence lifetime of modified Au nanoclusters (mAuNCs) by 4-(carboxybutyl) triphenylphosphonium bromide, we developed a fluorescence lifetime thermometer with high sensitivity and stability for the temperature of the intracellular mitochondria. A high relative temperature sensitivity of 2.8% and excellent photostability were achieved from the present thermometer. After incubation with L929 cells, the mAuNCs could be endocytosed into the cells and targeted the mitochondria, and the temperature changes at the L929 cells' mitochondria, which were stimulated by carbonyl cyanide 3-chlorophenylhydrazone and Ca2+, were successfully detected via the fluorescence lifetime images of the mAuNCs. Furthermore, utilizing the mAuNCs, we clarified the effect of Mg2+ on the temperature of the intracellular mitochondria. The strategy of employing a material with a long fluorescence lifetime and remarkable stability to fabricate the fluorescence lifetime thermometer for mitochondria can be used to design various thermometers for other organelles.


Assuntos
Mitocôndrias , Termômetros , Células HeLa , Humanos , Espectrometria de Fluorescência , Temperatura
8.
J Org Chem ; 86(7): 4932-4943, 2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33730490

RESUMO

A convenient preparation method of N-acylbenzoxazines has been developed, in which phenols react with nitriles and dimethyl sulfoxide (DMSO) in the presence of a catalytic amount of (COCl)2 in CH3CN or chloroform to afford the corresponding N-acylbenzoxazines in moderate-to-good yields. DMSO acts as a source of HCHO, which is generated in situ from the decomposition of a methoxydimethylsulfonium salt. A regeneration cycle of the methoxydimethylsulfonium salt is proposed, which is initiated by a catalytic amount of (COCl)2.


Assuntos
Dimetil Sulfóxido , Fenóis , Catálise , Clorofórmio , Nitrilas
9.
Appl Environ Microbiol ; 86(10)2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32169938

RESUMO

Biofilm formation by Pseudomonas aeruginosa contributes to its survival on surfaces and represents a major clinical threat because of the increased tolerance of biofilms to disinfecting agents. This study aimed to investigate the efficacy of 405-nm light-emitting diode (LED) illumination in eliminating P. aeruginosa biofilms formed on stainless steel coupons under different temperatures. Time-dependent killing assays using planktonic and biofilm cells were used to determine the antimicrobial and antibiofilm activities of LED illumination. We also evaluated the effects of LED illumination on the disinfectant susceptibility, biofilm structure, extracellular polymeric substance (EPS) structure and composition, and biofilm-related gene expression of P. aeruginosa biofilm cells. Results showed that the abundance of planktonic P. aeruginosa cells was reduced by 0.88, 0.53, and 0.85 log CFU/ml following LED treatment for 2 h compared with untreated controls at 4, 10, and 25°C, respectively. For cells in biofilms, significant reductions (1.73, 1.59, and 1.68 log CFU/cm2) were observed following LED illumination for 2 h at 4, 10, and 25°C, respectively. Moreover, illuminated P. aeruginosa biofilm cells were more sensitive to benzalkonium chloride or chlorhexidine than untreated cells. Scanning electron microscopy and confocal laser scanning microscopic observation indicated that both the biofilm structure and EPS structure were disrupted by LED illumination. Further, reverse transcription-quantitative PCR revealed that LED illumination downregulated the transcription of several genes associated with biofilm formation. These findings suggest that LED illumination has the potential to be developed as an alternative method for prevention and control of P. aeruginosa biofilm contamination.IMPORTANCEPseudomonas aeruginosa can form biofilms on medical implants, industrial equipment, and domestic surfaces, contributing to high morbidity and mortality rates. This study examined the antibiofilm activity of 405-nm light-emitting diode (LED) illumination against mature biofilms formed on stainless steel coupons. We found that the disinfectant susceptibility, biofilm structure, and extracellular polymeric substance structure and composition were disrupted by LED illumination. We then investigated the transcription of several critical P. aeruginosa biofilm-related genes and analyzed the effect of illumination temperature on the above characteristics. Our results confirmed that LED illumination could be developed into an effective and safe method to counter P. aeruginosa biofilm contamination. Further research will be focused on the efficacy and application of LED illumination for elimination of complicated biofilms in the environment.


Assuntos
Biofilmes/efeitos da radiação , Desinfecção/métodos , Luz , Pseudomonas aeruginosa/efeitos da radiação , Aço Inoxidável , Iluminação , Pseudomonas aeruginosa/fisiologia , Temperatura
10.
Pharmacol Res ; 155: 104693, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32057896

RESUMO

Hormone therapy continues to be a favourable option in the management of menopausal symptomatology, but the associated risk-benefit ratios with respect to neurodegenerative diseases remain controversial. The study aim was to determine the relation between menopausal hormone therapy and Alzheimer's disease, dementia, and Parkinson's disease in human subjects. A literature search was performed in PubMed/Medline, Cochrane collaboration, and Scopus databases from onset of the database to September 2019. Random-effects model was used to estimate pooled odd ratio (OR) and 95 % confidence intervals (CI). Subgroup analysis was performed based on the type and formulation of hormone. In addition, the time-response effect of this relationship was also assessed based on duration of hormone therapy. Associations between hormone therapy and Alzheimer's disease, dementia, and Parkinson's disease in menopausal women were reported in 28 studies. Pooled results with random effect model showed a significant association between hormone therapy and Alzheimer's disease (OR 1.08, 95 % CI 1.03-1.14, I2: 69 %). This relationship was more pronounced in patients receiving the combined estrogen-progestogen formulation. Moreover, a significant non-linear time-response association between hormone therapy and Alzheimer's disease was also identified (Coef1 = 0.0477, p1<0.001; Coef2 = -0.0932, p2<0.001). Similarly, pooled analysis revealed a significant association between hormone therapy and all-cause dementia (OR 1.16, 95 % CI 1.02-1.31, I2: 19 %). Interestingly, no comparable relationship was uncovered between hormone therapy as a whole and Parkinson's disease (OR 1.14, 95 % CI 0.95-1.38, I2: 65 %); however, sub-group analysis revealed a significant relationship between the disease and progestogen (OR 3.41, 95 % CI 1.23-9.46) or combined estrogen-progestogen formulation use (OR 1.49, 95 % CI 1.34-1.65). Indeed, this association was also found to be driven by duration of exposure (Coef1 = 0.0626, p1 = 0.04). This study reveals a significant direct relationship between the use of certain hormonal therapies and Alzheimer's disease, all-cause dementia, and Parkinson's disease in menopausal women. However, the association appears to shift in direct after five years in the context of Alzheimer's disease, adding further weight to the critical window or timing hypothesis of neurodegeneration and neuroprotection.


Assuntos
Doença de Alzheimer/epidemiologia , Demência/epidemiologia , Terapia de Reposição de Estrogênios , Doença de Parkinson/epidemiologia , Humanos
11.
Nanotechnology ; 31(36): 365502, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32442993

RESUMO

Intracellular thermometry with favorable biocompatibility and precision is essential for insight into temperature-related cellular events. Here, liquid-core nanocapsule ratiometric fluorescent thermometers (LCN-RFTs) were prepared by encapsulating thermosensitive organic fluorophores (N,N'-di(2-ethylhexyl)-3,4,9,10-perylene tetracarboxylic diimide, DEH-PDI) with hydrophobic solvent (2,2,4-trimethylpentane, TMP) into polystyrene/silica hybrid nanoshells. As the fluorescent thermosensitive unit of the LCN-RFT, the TMP solution of DEH-PDI was responsible for the fluorescence response to temperature. Benefitting from the hydrophilic nanoshells, the LCN-RFTs exhibited favorable anti-interference and biocompatibility. Furthermore, the LCN-RFTs showed an excellent precision of 0.02 °C-0.10 °C in a simulated physiological environment from 10.00 °C to 90.00 °C, and were employed to realize intracellular thermometry with an outstanding precision of 0.06 °C-0.14 °C. This work provides a feasible method of using hydrophobic organic fluorophores for intracellular thermometry by encapsulating them into nanocapsules.


Assuntos
Materiais Biocompatíveis/química , Corantes Fluorescentes/química , Imidas/química , Nanocápsulas/química , Perileno/análogos & derivados , Animais , Linhagem Celular , Camundongos , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Perileno/química , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termômetros
12.
Food Microbiol ; 86: 103337, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703870

RESUMO

Coenzyme Q0 (CoQ0) has demonstrated antitumor, anti-inflammatory, and anti-angiogenic activities. Cronobacter sakazakii is an opportunistic foodborne pathogen associated with high mortality in neonates. In this study, the antimicrobial activity and possible antimicrobial mechanism of CoQ0 against C. sakazakii were investigated. Moreover, the inactivation effect of CoQ0 on C. sakazakii in biofilms was also evaluated. The minimum inhibitory concentration (MIC) of CoQ0 against C. sakazakii strains ranged from 0.1 to 0.2 mg/mL. Treatment caused cell membrane dysfunction, as evidenced by cell membrane hyperpolarization, decreased intracellular ATP concentration and cell membrane integrity, and changes in cellular morphology. CoQ0 combined with mild heat treatment (45, 50, or 55 °C) decreased the number of viable non-desiccated and desiccated C. sakazakii cells in a time- and dose-dependent manner in reconstituted infant milk. Furthermore, CoQ0 showed effective inactivation activity against C. sakazakii in biofilms on stainless steel, reducing the number of viable cells and damaging the structure of the biofilm. These findings suggest that CoQ0 has a strong inactivate effect on C. sakazakii and could be used in food production environments to effectively control C. sakazakii and reduce the number of illnesses associated with it.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Cronobacter sakazakii/efeitos dos fármacos , Ubiquinona/análogos & derivados , Membrana Celular/efeitos dos fármacos , Cronobacter sakazakii/crescimento & desenvolvimento , Cronobacter sakazakii/fisiologia , Fórmulas Infantis/análise , Fórmulas Infantis/microbiologia , Testes de Sensibilidade Microbiana , Plâncton/efeitos dos fármacos , Plâncton/crescimento & desenvolvimento , Plâncton/fisiologia , Ubiquinona/farmacologia
13.
J Stroke Cerebrovasc Dis ; 29(8): 104928, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32689582

RESUMO

PURPOSE: Carotid atherosclerotic plaque is closely associated with cerebral white matter lesions (WMLs), while intraplaque neovascularization (IPN) contributes significantly to arterial remodeling and plaque vulnerability. In this study, we aim to evaluate the correlation of carotid IPN with cerebral WMLs. METHODS: The presence of IPN and WMLs were assessed by contrast-enhanced ultrasound (CEUS) and MRI respectively. IPN was evaluated utilizing semi-quantification visual grading scale and WMLs was divided according to Fazekas grading scale. We investigated the baseline data, Fazekas grades, and IPN grades among 269 participants. We explored the influences of each variable on Fazekas grades using ordinal logistic regression and evaluated the relationship between IPN grades and WMLs Fazekas grades. RESULTS: Increased age (OR: 1.06, P<0.001), hypertension (OR: 2.17, P=0.002), cerebral infarction (OR: 1.74, P=0.046), and elevated carotid IPN grading were significantly associated with aggravated Fazekas grades (grade 2 or 3). To be specific, people having grade 3, 2, and 1 carotid IPN were 25.84 (P<0.001), 10.64 (P<0.001), and 5.96 (P=0.010) times as likely to have elevated Fazekas grades compared with those who having grade 0 carotid IPN. CONCLUSION: Increased carotid IPN is independently correlated with aggravated cerebral WMLs.


Assuntos
Doenças das Artérias Carótidas/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Leucoencefalopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Neovascularização Patológica , Fosfolipídeos/administração & dosagem , Placa Aterosclerótica , Hexafluoreto de Enxofre/administração & dosagem , Ultrassonografia Doppler em Cores , Idoso , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/patologia , Feminino , Humanos , Leucoencefalopatias/complicações , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco
14.
J Environ Manage ; 269: 110804, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32561011

RESUMO

A well-developed economy and low-carbon emission intensity are important characteristics of low-carbon cities; they also represent important tasks for achieving global climate change mitigation goals. It is seldom discussed, however, how we should identify frontrunner cities from which low-carbon development experiences can be gleaned and then implemented in neighboring cities. This study, therefore, proposed a simple indicator-the "good neighbor index"-to identify frontrunner cities in low-carbon transformation based on economic and emission performance. Based on this indicator, we identified "good neighbors" in static and dynamic views for China. The results showed that the static good neighbors in 2015 were mostly large cities with higher incomes and better industrial structures whereas the dynamic neighbors achieved better economic growth and emission reductions from 2005 to 2015, though their economic and emissions statuses were generally worse. The good neighbor list is not consistent with the list of national low-carbon pilot cities, which has largely overlooked the experiences of some fast-growing cities. These results have policy implications for the Chinese government in terms of promoting the low-carbon transformation of cities. The study can also provide a reference for other countries in addressing climate change at the city level.


Assuntos
Carbono , Desenvolvimento Econômico , China , Cidades , Mudança Climática
15.
BMC Neurol ; 19(1): 276, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31703639

RESUMO

BACKGROUND: Internal carotid artery dissection has been well recognized as a major cause of ischaemic stroke in young and middle-aged adults. However, internal carotid artery dissection induced hypoglossal nerve palsy has been seldom reported and may be difficult to diagnose in time for treatment; even angiography sometimes misses potential dissection, especially when obvious lumen geometry changing is absent. CASE PRESENTATION: We report a 42-year-old man who presented with isolated hypoglossal nerve palsy. High-resolution MRI showed the aetiological dissected internal carotid artery. In addition, a potential genetic structural defect of the arterial wall was suggested due to an exon region mutation in the polycystic-kidney-disease type 1 gene. CONCLUSIONS: Hypoglossal nerve palsy is a rare manifestations of carotid dissection. High-resolution MRI may provide useful information about the vascular wall to assist in the diagnosis of dissection. High-throughput sequencing might be useful to identify potential cerebrovascular-related gene mutation, especially in young individuals with an undetermined aetiology.


Assuntos
Dissecação da Artéria Carótida Interna/complicações , Dissecação da Artéria Carótida Interna/genética , Doenças do Nervo Hipoglosso/etiologia , Canais de Cátion TRPP/genética , Adulto , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Mutação
16.
Nanotechnology ; 31(4): 045402, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31604344

RESUMO

In this work, quasi-two-dimensional spinel ZnCo2O4 (ZCO) nanosheets comprising ZCO nanoparticles of different grain size were prepared via a facile solvothermal method and followed by post-treatment. It shows that the ZCO with a small grain size can be obtained by a fast cooling post-treatment. To enhance the conductivity of ZCO, uniform and compact ZCO nanosheets were in situ grown on reduced graphene oxide (rGO), which was employed as the template. When used as an anode for lithium ion batteries (LIBs), rGO@ZCO has a highly reversible capacity of 1107.2 mAh · g-1 at 100 mA · g-1 after 100 cycles, which is the highest among all ZCO samples. Moreover, when the current density is from 50 to 500 mA · g-1, the capacity of rGO@ZCO decreased from 1046.5 to 527.6 mAh · g-1, implying superior rate ability. The electrochemical analysis, together with calculations demonstrates that the unique structure is beneficial to promote charge transport and adapt the volume change in the charge-discharge process, resulting in expected LIB performance.

17.
Appl Microbiol Biotechnol ; 103(20): 8545-8557, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31468089

RESUMO

Salmonella Typhimurium, a common Gram-negative foodborne pathogen, threatens public health and hinders the development of the food industry. In this study, we evaluated the antibiofilm activity of coenzyme Q0 (CoQ0) against S. Typhimurium. Besides, the inhibition of the S. Typhimurium's adhesion to and invasion of Caco-2 cells and its survival and replication in RAW 264.7 cells by CoQ0 were also explored. The minimum inhibitory concentrations and minimal bactericidal concentrations of CoQ0 against Salmonella were both 100-400 µg/mL. Salmonella Typhimurium biofilm formation was effectively inhibited by subinhibitory concentrations (SICs) of CoQ0. The CoQ0-affected biofilm morphology was observed with light microscopy and field-emission scanning electron microscopy. CoQ0 at SICs reduced the swimming motility and quorum sensing of S. Typhimurium and repressed the transcription of critical virulence-related genes. CoQ0 at SICs also clearly reduced the adhesion of S. Typhimurium to and its invasion of Caco-2 cells and reduced its survival and replication within RAW 264.7 macrophage cells. These findings suggest that CoQ0 has strong antibiofilm activity and can be used as an anti-infectious agent against Salmonella.


Assuntos
Antibacterianos/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Benzoquinonas/metabolismo , Biofilmes/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Salmonella typhimurium/efeitos dos fármacos , Animais , Células CACO-2 , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Células RAW 264.7
18.
Eur Arch Otorhinolaryngol ; 274(3): 1327-1338, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27645473

RESUMO

Although there have been many studies identifying clinical and pathologic factors that may predict central lymph node metastases (CLNM) in papillary thyroid microcarcinoma (PTMC) patients without clinically cervical lymph node metastasis (cN0), the results were inconsistent. And whether prophylactic central lymph node dissection (pCLND) should be performed in cN0 PTMC remains controversial. The EMBASE, PubMed, MEDLINE and the Cochrane Library were searched until Oct 2015 to identify relevant studies. Primary outcomes were clinical and pathologic factors for CLNM. Secondary outcomes included CLNM rate, surgical complications of hypocalcaemia and recurrent laryngeal nerve(RLN) injury and neck recurrences. Statistical analysis was performed using Stata 12.0. Fourteen eligible studies enrolling 4573 patients were included in this meta-analysis. The overall incidence of CLNM was 33 % (95 % CI 29-37). An elevated risk of CLNM was significantly associated with male gender (OR 2.33, 95 % CI 1.71-3.17), age <45 years (OR 1.27, 95 % CI 1.08-1.48), tumor size >5 mm (OR 2.16, 95 % CI 1.87-2.50), multifocality (OR 1.73, 95 % CI 1.45-2.05), extrathyroidal extension (OR 1.99, 95 % CI 1.66-2.37) and lymphovascular invasion (OR 3.87, 95 % CI 1.64-9.10), but not with thyroid bilaterality (OR 1.41, 95 % CI 0.89-2.22) and chronic lymphocytic thyroiditis (OR 0.98, 95 % CI 0.66-1.47). The pooled frequency of permanent hypocalcaemia, permanent RLN injury and neck recurrences was 1.1, 0.5 and 2.8 %, respectively. cN0 PTMC patients have a considerable CLNM rate and have a low pooled incident of surgical complications and neck recurrences with pCLND. Six unfavorable clinical and pathologic factors, which were significantly associated with CLNM, were identified. These findings may help guide the application of pCLND or subsequent treatment in cN0 PTMC.


Assuntos
Carcinoma Papilar/patologia , Neoplasias da Glândula Tireoide/patologia , Carcinoma Papilar/cirurgia , Humanos , Hipocalcemia/etiologia , Incidência , Metástase Linfática , Esvaziamento Cervical , Recidiva Local de Neoplasia , Complicações Pós-Operatórias , Traumatismos do Nervo Laríngeo Recorrente/etiologia , Fatores de Risco , Fatores Sexuais , Neoplasias da Glândula Tireoide/cirurgia
19.
J Org Chem ; 81(11): 4713-9, 2016 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-27137813

RESUMO

An efficient protocol for the synthesis of sulfonamides via the electrochemical oxidative amination of sodium sulfinates has been developed. The chemistry proceeds in a simple undivided cell employing a substoichiometric amount of NH4I that serves both as a redox catalyst and a supporting electrolyte; in this manner additional conducting salt is not required. A wide range of substrates, including aliphatic or aromatic secondary and primary amines, as well as aqueous ammonia, proved to be compatible with the protocol. Scale-up was possible, thereby demonstrating the practicality of the approach. The electrolytic process avoids the utilization of external oxidants or corrosive molecular iodine and therefore represents an environmentally benign means by which to achieve the transformation.

20.
J Org Chem ; 81(23): 11565-11573, 2016 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-27934459

RESUMO

An efficient electrochemical protocol for the synthesis of α-amino ketones via the oxidative cross-dehydrogenative coupling of ketones and secondary amines has been developed. The electrochemistry performs in a simple undivided cell using NH4I as a redox catalyst and a cheap graphite plate as electrodes under constant current conditions. Gram-scale reaction demonstrates the practicality of the protocol. The reaction is proposed to procced through an initial α-iodination of ketone, followed by a nucleophilic substitution of amines.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA