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1.
Nat Commun ; 12(1): 4880, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385444

RESUMO

Accurate and imperceptible monitoring of electrophysiological signals is of primary importance for wearable healthcare. Stiff and bulky pregelled electrodes are now commonly used in clinical diagnosis, causing severe discomfort to users for long-time using as well as artifact signals in motion. Here, we report a ~100 nm ultra-thin dry epidermal electrode that is able to conformably adhere to skin and accurately measure electrophysiological signals. It showed low sheet resistance (~24 Ω/sq, 4142 S/cm), high transparency, and mechano-electrical stability. The enhanced optoelectronic performance was due to the synergistic effect between graphene and poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which induced a high degree of molecular ordering on PEDOT and charge transfer on graphene by strong π-π interaction. Together with ultra-thin nature, this dry epidermal electrode is able to accurately monitor electrophysiological signals such as facial skin and brain activity with low-motion artifact, enabling human-machine interfacing and long-time mental/physical health monitoring.


Assuntos
Eletrodos , Eletrofisiologia/métodos , Epiderme/fisiologia , Desenho de Equipamento/métodos , Monitorização Fisiológica/métodos , Dispositivos Eletrônicos Vestíveis , Artefatos , Compostos Bicíclicos Heterocíclicos com Pontes/química , Condutividade Elétrica , Eletrofisiologia/instrumentação , Eletrofisiologia/normas , Desenho de Equipamento/normas , Grafite/química , Humanos , Estrutura Molecular , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/normas , Movimento (Física) , Polímeros/química , Poliestirenos/química , Pele
2.
J Immunother Cancer ; 9(6)2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34172514

RESUMO

BACKGROUND: The discovery of checkpoint inhibitors towards cytotoxic T-lymphocyte protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) has been revolutionary for the treatment of cancers. These therapies have only offered an average of 20%-30% response rates across the tumor spectrum and the combination of agonists towards the tumor-necrosis superfamily members, such as 4-1BB and CD40, has shown potent efficacy in preclinical studies; however, these agonists have exhibited high degrees of toxicity with limited efficacy in human trials. In this study, we have generated a single-domain antibody towards a unique epitope of 4-1BB that limits its potential on-target toxicity while maintaining sufficient potency. This 4-1BB binder is ideal for use in the engineering of multispecific antibodies to localize 4-1BB activation within the tumor microenvironment, as shown here by a anti-PD-L1/4-1BB bispecific candidate (PM1003). METHODS: To determine the functional activity of the 4-1BB- and PD-L1-binding elements of PM1003, in vitro luciferase reporter and primary cell assays were used to test the potency of programmed cell death 1 ligand 1 (PD-L1) blockade and PD-L1-mediated 4-1BB activation via cross-bridging. X-ray crystallography was conducted to resolve the binding epitopes of the respective binding arms, and accurate binding kinetics were determined using standard affinity measurement techniques. Human 4-1BB and/or PD-L1 knock-in mice were used in cancer models for testing the in vivo antitumor efficacy of PM1003, and safety was evaluated further. RESULTS: PM1003 shows potent activation of 4-1BB and blockade of PD-L1 in cell-based assays. 4-1BB activation was exerted through the bridging of PD-L1 on target cells and 4-1BB on effector cells. No PD-L1-independent activation of 4-1BB was observed. Through X-ray crystallography, a unique binding epitope in the cysteine-rich domain 4 (CRD4) region was resolved that provides high potency and potentially low on-target toxicity as determined by primary immune cell assays and toxicity evaluation in vivo. CONCLUSIONS: A unique single-domain antibody was discovered that binds to the CRD4 domain of 4-1BB. When incorporated into a 4-1BB/PD-L1 bispecific (PM1003), we have shown the potent inhibition of PD-L1 activity with 4-1BB agonism upon cross-bridging with PD-L1 in vitro. Antitumor activity with minimal toxicity was found in vivo. Thus, PM1003 is a uniquely differentiating and next generation therapeutic agent for cancer therapy.

3.
ACS Appl Mater Interfaces ; 12(50): 56361-56371, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33270412

RESUMO

Epidermal electronics is regarded as the next-generation technology, and graphene is a promising electrode, which is a key building block of such devices. However, graphene has a tendency to crack at small strains with a rapidly increased resistance upon stretching. Here, to enable graphene applicable in epidermal electronics, we designed a novel graphene structure that is molybdenum chloride (MoCl5)-intercalated few-layer graphene (Mo-FLG) fabricated in a confined environment. In the case of bilayer graphene (BLG), MoCl5-intercalated bilayer graphene (Mo-BLG) exhibited a low sheet resistance of 40 Ω/square (sq) at a transmittance of 80%. Due to the self-barrier doping effect, the sheet resistance increased to only 60 Ω/sq after exposing to the atmosphere over 1 month. Transferred onto elastomer substrates, Mo-BLG can work as an electrode up to 80% strain and maintain a high conductivity that is durable over 2000 cycles at 30% strain. This mechano-electrostability is attributed to the special intercalated structure where the intercalated dopants act as lubricants to weaken the layer-layer interaction and allow a certain degree of sliding, as well as electrical crack-connectors to bridge the cracked domains at a high strain. Mo-BLG can be applied as epidermal electrodes to monitor electrophysiological signals such as electrocardiogram (ECG), electrooculogram (EOG), electroencephalography (EEG), and surface electromyogram (sEMG) with high signal-to-noise ratios (SNRs) comparable to commercial Ag/AgCl electrode. This is the first demonstration of epidermal electrodes based on intercalation-doped graphene applied in health monitoring, shedding light on the future development of graphene-based epidermal electronics.


Assuntos
Eletrocardiografia/instrumentação , Eletroencefalografia/instrumentação , Eletromiografia/instrumentação , Grafite/química , Cloretos/química , Elastômeros/química , Condutividade Elétrica , Eletrodos , Epiderme/fisiologia , Humanos , Molibdênio/química , Razão Sinal-Ruído
4.
Water Sci Technol ; 82(5): 998-1008, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33031076

RESUMO

The feasibility of an advanced oxidation process based upon sodium persulfate (SPS) activated simultaneously by heat (50 °C) and nanoscale zero-valent iron (nZVI) on benzene removal was investigated. The experimental results strongly showed the synergistic effect of thermal and nZVI activation to SPS and benzene removal was enhanced with the increase of SPS/nZVI/benzene molar ratio. Specifically, 94% of benzene could be removed in 1 hr at 50 °C at the SPS/nZVI/benzene molar ratio of 10/5/1. The radical scavenger tests and electron paramagnetic resonance (EPR) analysis confirmed that SO4•- was the predominant species contributing to benzene degradation. Further, the effects of the solution matrix on benzene elimination were investigated. The results indicated that benzene destruction in the thermally activated SPS/nZVI system performed better under acidic conditions, and the high concentration of both Cl- and HCO3 - had adverse effects on benzene elimination. The test for the performance of benzene degradation in the actual groundwater demonstrated that benzene could be degraded entirely at SPS/nZVI/benzene molar ratio of 40/40/1 at 50 °C, indicating that the synergistic catalysis of thermal and nZVI activation to SPS is exploitable and the thermally activated SPS/nZVI system can be applicable to the remediation of benzene contaminated groundwater.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Benzeno , Ferro , Oxirredução , Poluentes Químicos da Água/análise
5.
MAbs ; 12(1): 1804241, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804015

RESUMO

In the absence of a proven effective vaccine preventing infection by SARS-CoV-2, or a proven drug to treat COVID-19, the positive results of passive immune therapy using convalescent serum provide a strong lead. We have developed a new class of tetravalent, biparatopic therapy, 89C8-ACE2. It combines the specificity of a monoclonal antibody (89C8) that recognizes the relatively conserved N-terminal domain of the viral Spike (S) glycoprotein, and the ectodomain of ACE2, which binds to the receptor-binding domain of S. This molecule shows exceptional performance in vitro, inhibiting the interaction of recombinant S1 to ACE2 and transduction of ACE2-overexpressing cells by S-pseudotyped lentivirus with IC50s substantially below 100 pM, and with potency approximately 100-fold greater than ACE2-Fc itself. Moreover, 89C8-ACE2 was able to neutralize authentic viral infection in a standard 96-h co-incubation assay at low nanomolar concentrations, making this class of molecule a promising lead for therapeutic applications.


Assuntos
Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus , Pandemias , Peptidil Dipeptidase A/efeitos dos fármacos , Pneumonia Viral , Enzima de Conversão de Angiotensina 2 , Anticorpos Monoclonais/farmacologia , COVID-19 , Desenho de Fármacos , Descoberta de Drogas , Humanos , Proteínas Recombinantes , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/efeitos dos fármacos
6.
Nat Nanotechnol ; 15(9): 811, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32606390

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

7.
Chemosphere ; 257: 127223, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32534295

RESUMO

The degradation performance of trichloroethylene (TCE) by sodium percarbonate (SPC) activated with citric acid (CA) chelated Fe(II) in the presence of nonionic surfactant Tween-80 was investigated. The addition of CA successfully prevented the precipitation of iron and facilitated TCE degradation. However, Tween-80 had an inhibitory effect on TCE degradation mainly due to the competition of ∗OH between Tween-80 and TCE. The effect of SPC and Fe(II) dosage on TCE degradation was also explored and the results displayed that 87.2% of TCE could be degraded in 15 min at the SPC/Fe(II)/CA/TCE molar ratio of 3/4/2/1. Free radical probe tests confirmed that both O2-∗ and ∗OH were generated in the SPC/Fe(II)/CA system. Free radical scavenging tests implied that the degradation of TCE in the SPC/Fe(II)/CA system was mainly attributed to ∗OH, while O2-∗ was only partially involved in the degradation of TCE. In addition, TCE removal was suppressed with the raising of the initial solution pH from 3.0 to 9.0. The actual groundwater (containing Tween-80) tests confirmed that 93.2% of TCE degradation could be achieved at the SPC/Fe(II)/CA/TCE molar ratio of 30/40/10/1 and strongly demonstrated that the SPC/Fe(II)/CA process has potential for the in situ treatment of TCE contaminated groundwater in the presence of surfactant Tween-80. In conclusion, TCE degradation by Fe(II) activated SPC system in the presence of Tween-80 can be significantly enhanced with the addition of CA, and this finding offers an innovative direction for removing chlorinated organic contaminants from groundwater in contaminated site after surfactant solubilization treatment.


Assuntos
Carbonatos/química , Tensoativos/química , Tricloroetileno/química , Poluentes Químicos da Água/química , Quelantes , Ácido Cítrico , Compostos Ferrosos/química , Água Subterrânea , Ferro , Oxirredução , Polissorbatos , Surfactantes Pulmonares , Poluentes Químicos da Água/análise
8.
Cartilage ; : 1947603520912322, 2020 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-32281401

RESUMO

OBJECTIVE: Osteoarthritis (OA) is a prevalent chronic multifactorial degenerative disease characterized by joint tissue inflammation, osteophyte formation, subchondral bone sclerosis, and articular cartilage degradation. Low-intensity pulsed ultrasound (LIPUS), a noninvasive ultrasound technique, is widely used to attenuate diseases. The aim of this study was to investigate whether LIPUS can ameliorate OA, and to explore its underlying molecular mechanism. DESIGN: The OA model was established in a C57BL/6 mouse by the anterior cruciate ligament transaction method. OA was assessed using arthritis scoring and weightbearing parameters. Chondrocyte proliferation was detected by a CCK-8 assay. The levels of interleukin-6 (IL-6), IL-8 and tumor necrosis factor-α (TNF-α) in synovial fluid of the mice were measured by enzyme-linked immunosorbent assay. RESULTS: In OA mice, the arthritis score and weightbearing abilities were dramatically improved by LIPUS treatment. LIPUS also remarkably declined the levels of inflammatory cytokines IL-6, IL-8, and TNF-α in synovial fluid of OA mice. Moreover, LIPUS promoted chondrocyte proliferation and differentiation by activating focal adhesion kinase (FAK) signaling. Inhibition of FAK significantly blocked LIPUS-mediated cell proliferation and differentiation in vitro, as well as inflammation condition in OA mice. CONCLUSION: LIPUS alleviates OA through promoting chondrocytes proliferation and differentiation by activating FAK, which could act as an intervening target for OA treatment.

9.
Chem Eng J ; 362: 243-250, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31588180

RESUMO

This study investigated the reductive initiation for the depletion of highly oxidized/perhalogenated pollutants, specifically the degradation of carbon tetrachloride (CT) was induced by adding methanol (MeOH) into a ferrous ion (Fe(II)) activated calcium peroxide (CaO2) system. The results indicated that CT could be completely degraded within 20 min at CaO2/Fe(II)/MeOH/CT molar ratio of 30/40/10/1 in this system. Scavenging tests suggested that both superoxide radical anion (O2 •-) and carbon dioxide radical anion (CO2 •-) were predominant reactive species responsible for CT destruction. Hydroxymethyl radicals (•CH2OH), an intermediate in the transformation of MeOH, could also initiate CT degradation by reducing C-Cl bond. GC/MS analysis identified CHCl3, C2Cl4, and C2Cl6 as the intermediates accompanied by CT destruction, and a reduction mechanism for CT degradation was proposed accordingly. In addition, the impact of solution matrix and initial solution pH were evaluated, and the results showed that Cl-, NO3 -, and HCO3 - had adverse effects on CT degradation. Moreover, the alkaline condition was unfavorable to CT depletion. In conclusion, the results obtained in the actual groundwater tests encouragingly demonstrated that the CaO2/Fe(II)/MeOH process is a highly promising technique for the remediation of CT-contaminated groundwater.

10.
J Hazard Mater ; 368: 506-513, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30710779

RESUMO

Two carboxylic acids (formic acid (FA) and citric acid (CIT)) enhanced the Fenton process using Fe(II)-activated calcium peroxide (CP) to develop a hydroxyl (HO) and carbon dioxide radical (CO2-) coexistence process for the simultaneous redox-based degradation of three chlorinated hydrocarbons (CHs), namely carbon tetrachloride (CT), tetrachloroethene (PCE), and trichloroethene (TCE), was investigated. The experimental results showed that CT removal was increased while PCE and TCE degradation were decreased with the addition of FA to the Fe(II)/CP system. However, addition of CIT to the Fe(II)/CP/FA system enhanced the removal efficiency of all three contaminants. For example, 81.7%, 79.4%, and 96.1% of CT, PCE, and TCE, respectively, were removed simultaneously under the optimal molar ratio of 12/12/12/12/1 of CIT/CP/Fe(II)/FA/CHs. Mechanism study confirmed the specific roles of HO and secondarily generated CO2- radical. PCE and TCE were degraded oxidatively by HO while CT was degraded via reductive dechlorination by CO2-. Carbonate reduced PCE and TCE degradation in actual groundwater as it consumed reactive oxygen species, whereas humic acid and neutral pH had minimal impact on contaminant removal. These results can help us better understand the synergistic effects of carboxylic acids in the modified Fenton process for the redox degradation of refractory chlorinated hydrocarbons.

11.
Chem Commun (Camb) ; 55(10): 1414-1417, 2019 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-30640320

RESUMO

A facile and efficient strategy is described in this communication for preparing a molecular catalyst/semiconductor hybrid photoanode by immobilizing a cobalt cubane water oxidation catalyst onto a porous BiVO4 electrode via electrochemical polymerization. With the introduction of Vpa as the anchoring linkage, the poly-1/Vpa/Al2O3/BiVO4 photoanode exhibits high performance as well as stability for photoelectrochemical water oxidation.

12.
Sep Purif Technol ; 226: 13-21, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31933532

RESUMO

In this study, nCaO2 was synthesized successfully and applied in the Fe(II)-based catalytic environments in investigating trichloroethylene (TCE) removal performance. nCaO2 with the particle sizes in the range of 50-200 nm was prepared, and it performed better for TCE removal when compared to the conventional CaO2. Further experimental results showed that 70.4% of TCE could be removed in 180 min at the nCaO2/Fe(II)/TCE molar ratio of 1/2/1, while this data was elevated to 86.1% in the presence of citric acid (CA) at the nCaO2/Fe(II)/CA/TCE molar ratio of 1/2/2/1 in the same test period. Probe compound tests, specifically designed for free radicals confirmation, demonstrated the presence of HO• and O2 -•. Moreover, scavenging tests indicated that HO• was the major radical responsible for TCE degradation but O2 -• promoted the removal of TCE in both nCaO2/Fe(II) and nCaO2/Fe(II)-CA system. In addition, the effects of initial solution pH and anions (Cl-, HCO3 -) were also evaluated. The performance of TCE degradation in actual groundwater demonstrated that both nCaO2/Fe(II) and nCaO2/Fe(II)-CA systems can be applicable for TCE removal in ISCO practice and the nCaO2/Fe(II)-CA system is much promising technique. These fundamental data strongly confirmed the feasibility and potential of nCaO2 based technique in the remediation of TCE contaminated groundwater.

13.
Environ Technol ; 40(3): 356-364, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29069979

RESUMO

In this study, the degradation performance of carbon tetrachloride (CT) by sodium percarbonate (SPC) activated with Fe(II) in the presence of ethyl alcohol (EA) was investigated. The experimental results showed that CT could be readily degraded and the optimal EA/Fe(II)/SPC/CT molar ratio for CT reduction was 100/50/20/1. Superoxide radical anion ( ) and hydroxyethyl radical (•CHCH3OH, HER) were the predominant radical species responsible for CT degradation and EA could regulate the generation of and HER in the system. Further investigation for the solution matrix effects suggested that Cl-, , , and humic acid had negligible influences on CT degradation, while had negative effect in EA/Fe(II)/SPC system. On the other hand, the application of SPC/Fe(II)/EA technique is favorable to acidic condition is effective at a wide pH range of 3.0-7.0. In summary, CT degradation in Fe(II)-activated SPC system can be significantly promoted by addition of solvents, and these findings provide an innovative technology for the degradation of highly oxidized organic contaminants.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Tetracloreto de Carbono , Carbonatos , Etanol , Compostos Ferrosos , Oxirredução
14.
Sci Rep ; 8(1): 12194, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-30111775

RESUMO

Farey graphs are simultaneously small-world, uniquely Hamiltonian, minimally 3-colorable, maximally outerplanar and perfect. Farey graphs are therefore famous in deterministic models for complex networks. By lacking of the most important characteristics of scale-free, Farey graphs are not a good model for networks associated with some empirical complex systems. We discuss here a category of graphs which are extension of the well-known Farey graphs. These new models are named generalized Farey graphs here. We focus on the analysis of the topological characteristics of the new models and deduce the complicated and graceful analytical results from the growth mechanism used in generalized Farey graphs. The conclusions show that the new models not only possess the properties of being small-world and highly clustered, but also possess the quality of being scale-free. We also find that it is precisely because of the exponential increase of nodes' degrees in generalized Farey graphs as they grow that caused the new networks to have scale-free characteristics. In contrast, the linear incrementation of nodes' degrees in Farey graphs can only cause an exponential degree distribution.

15.
Life Sci ; 208: 232-238, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30005830

RESUMO

AIMS: Osteosarcoma is one of the most aggressive types of primary bone cancer that responds poorly to radiotherapy frequently. The gene associated with retinoid-interferon mortality (GRIM-19) is a tumor suppressor that mediates cell apoptosis in multiple cancer types. However, the role of GRIM-19 in osteosarcoma and the underlying mechanism remain unclear. This study was designed to investigate the role and the underlying mechanism of GRIM-19 in osteosarcoma progression. MATERIALS AND METHODS: Osteosarcoma tissues and cell lines were utilized to analyze the expressions of GRIM-19 in osteosarcoma by qRT-PCR and Western blot. Methods containing flow cytometry, irradiation exposure, cells inoculation, plasmid transfection, and protein immunoprecipitation were used to investigate the underlying mechanisms of GRIM-19 in osteosarcoma progression. KEY FINDINGS: GRIM-19 is downregulated in osteosarcoma tissues and cell lines. Exposure to radiation induces osteosarcoma cell apoptosis by upregulation of p53 both in U2OS (p53-wt) and exogenous p53-introduced MG-63 (p53-null) osteosarcoma cells. Overexpression of GRIM-19 accelerates radiation-induced osteosarcoma cells apoptosis by p53 stabilization ex vivo and in vivo. Mechanistically, forced expression of GRIM-19 diminishes the activity of E3 ubiquitin-protein ligase mouse double minute 2 homolog (MDM2), a specific p53 protease, results in the accumulation of p53 and activation of p53-mediated apoptosis. SIGNIFICANCE: GRIM-19 was proved to modulate radiation-induced osteosarcoma cells apoptosis in a p53 dependent manner by mediating MDM2 activity, which sheds light on the development of GRIM-19-based molecular target therapy on osteosarcoma.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/efeitos da radiação , Neoplasias Ósseas/patologia , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , NADH NADPH Oxirredutases/metabolismo , Osteossarcoma/patologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/radioterapia , Estudos de Casos e Controles , Proliferação de Células/efeitos da radiação , Humanos , Camundongos , NADH NADPH Oxirredutases/genética , Osteossarcoma/metabolismo , Osteossarcoma/radioterapia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Raios X , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Environ Sci Pollut Res Int ; 25(15): 15019-15028, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29552717

RESUMO

The occurrence and health risks of organotins (OTs) in the waterworks and source water in the Three Gorges Reservoir Region (TGRR), China were assessed in this study. Water samples were collected at four waterworks (A, B, C, and D) in March and July 2012 to analyze butyltins (BTs) and phenyltins (PTs) using a gas chromatography-mass spectrometry (GC-MS) system. Our results showed that both the waterworks and their nearby water sources were polluted by OTs, with PTs being the most dominant species. Monobutyltin (MBT), monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) were detected in most of the analyzed water samples. The highest concentrations of OTs in influents, effluents, and source water in March were 52.81, 17.93, and 55.32 ng Sn L-1, respectively. Furthermore, significant seasonal changes in OTs pollution were observed in all samples, showing pollution worse in spring compared with summer. The removal of OTs by the conventional treatment processes was not stable among the waterworks. The removal efficiency of OTs in July reached 100% at plant B, while that at plant C was only 38.8%. The source water and influents shared similar composition profiles, concentrations, and seasonal change of OTs, which indicated that OTs in the waterworks were derived from the source water. A health risk assessment indicated that the presence of OTs in the waterworks would not pose a significant health risk to the population, yet their presence should not be ignored.


Assuntos
Compostos Orgânicos de Estanho/toxicidade , Rios , Poluentes Químicos da Água/toxicidade , China , Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos de Estanho/análise , Medição de Risco , Poluentes Químicos da Água/análise , Abastecimento de Água
18.
Sheng Wu Gong Cheng Xue Bao ; 33(7): 1109-1123, 2017 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-28869731

RESUMO

Arginine kinase (AK) is a key enzyme in energy metabolism of invertebrates and plays an important regulatory role in the life activities such as growth and development, nutrition utilization, immune resistance and stress response. Arginine kinase of Bombyx mori (BmAK) is related to the energy balance and anti-NPV process, but there is little research on its molecular structure and enzymatic properties. We cloned the ORF sequence of BmAK gene, and analyzed chromosomal localization, genomic structure, mRNA structure, secondary and tertiary structure. Phylogenetic analysis indicated that AK was highly conserved in evolution. Soluble recombinant BmAK was obtained by prokaryotic expression, and purified by Ni-NTA affinity chromatography. The circular dichroism spectroscopy showed that BmAK contained α-helix structures, and its α-helix structures were relatively stable in the pH range between 5 and 10. Enzyme activity analysis showed that the optimum temperature of BmAK was 30 ℃ and the optimum pH of BmAK was 7.5. The optimal temperature of BmAK was 25 ℃. Between 15 ℃ and 30 ℃, the structure and activity of BmAK was relatively stable. The structure of BmAK was relatively stable at pH 7.0. Our findings reveal the structure and function of BmAK to develop novel green safe and environmentally friendly insecticides.


Assuntos
Arginina Quinase/metabolismo , Bombyx/enzimologia , Proteínas de Insetos/metabolismo , Animais , Arginina Quinase/genética , Clonagem Molecular , Proteínas de Insetos/genética , Conformação de Ácido Nucleico , Filogenia , Conformação Proteica , Temperatura
19.
ChemSusChem ; 10(16): 3268-3275, 2017 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-28612494

RESUMO

The rational design of active photoanodes for photoelectrochemical (PEC) water splitting is crucial for future applications in sustainable energy conversion. A combination of catalysts with photoelectrodes is generally required to improve surface kinetics and suppress surface recombination. In this study, we present WO3 photoanode modified with the iridium complex [(H4 dphbpy)IrIII (Cp*)Cl]Cl (Ir-PO3 H2 ; H4 dphbpy=2,2'-bipyridine-4,4'-bisphosphonic acid, Cp*=pentamethylcyclopentadiene (WO3 +Ir-PO3 H2 )- for PEC water oxidation. When Ir-PO3 H2 is anchored to a WO3 electrode, the photoanode shows a significant improvement in both photocurrent and faradaic efficiency compared to the bare WO3 photoanode. Under simulated sunlight illumination (AM 1.5G, 100 mW cm-2 ) with an applied bias of 1.23 V (vs. reversible hydrogen electrode), the photoanode exhibits a photocurrent of 1.16 mA cm-2 in acidic conditions, which is double that of the bare WO3 photoanode. The faradaic efficiency is promoted from 56 % to 95 %. Kinetic studies reveal that Ir-PO3 H2 exhibits a different interfacial charge-transfer mechanism on the WO3 photoanode for PEC water oxidation compared to iridium oxide. Ir-PO3 H2 , as a water-oxidation catalyst, can accelerate the surface charge transfer through rapid surface kinetics.


Assuntos
Irídio/química , Óxidos/química , Processos Fotoquímicos , Tungstênio/química , Catálise , Eletrodos , Transporte de Elétrons , Cinética
20.
Molecules ; 22(5)2017 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-28468293

RESUMO

Silk sericin has great potential as a biomaterial for biomedical applications due to its good hydrophilicity, reactivity, and biodegradability. To develop multifunctional sericin materials for potential antibacterial application, a one-step synthesis method for preparing silver nanoparticles (AgNPs) modified on polydopamine-coated sericin/polyvinyl alcohol (PVA) composite films was developed. Polydopamine (PDA) acted as both metal ion chelating and reducing agent to synthesize AgNPs in situ on the sericin/PVA composite film. Scanning electron microscopy and energy dispersive spectroscopy analysis revealed that polydopamine could effectively facilitate the high-density growth of AgNPs as a 3-D matrix. X-ray diffractometry studies suggested the synthesized AgNPs formed good face-centered cubic crystalline structures. Contact angle measurement and mechanical test indicated AgNPs modified PDA-sericin/PVA composite film had good hydrophilicity and mechanical property. The bacterial growth curve and inhibition zone assays showed the AgNPs modified PDA-sericin/PVA composite film had long-term antibacterial activities. This work develops a new method for the preparation of AgNPs modified PDA-sericin/PVA film with good hydrophilicity, mechanical performance and antibacterial activities for the potential antimicrobial application in biomedicine.


Assuntos
Antibacterianos/síntese química , Indóis/química , Nanopartículas Metálicas/química , Polímeros/química , Álcool de Polivinil/química , Sericinas/química , Prata/química , Adsorção , Antibacterianos/farmacologia , Bandagens , Materiais Revestidos Biocompatíveis/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Nanocompostos/química , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Resistência à Tração , Molhabilidade
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