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1.
Int J Biol Macromol ; 151: 312-321, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32084462

RESUMO

The characteristics of single domain and ease of gene manipulation of the single domain antibody (sdAb) make it suitable for affinity maturation in vitro. Since the affinity of antibodies can influence the immunoassays' sensitivity, a nanobody (Nb), the anti-ochratoxin A sdAb (AOA-sdAb), was herein selected as the model antibody to explore feasible approach for improving its affinity. Homology modeling and molecular docking were used to analyze the interaction between OTA and the AOA-sdAb. After alanine scanning verification, Gly53, Met79, Ser102, and Leu149 were determined as the key amino acids of the AOA-sdAb. Two site-directed saturated mutation libraries were constructed by two-site mutation against those four key amino acids. After biopanning and identification, a mutant Nb-G53Q&S102D was obtained with a half maximal inhibition concentration (IC50) of 0.29 ng/mL and a KD value of 52 nM, which is 1.4-fold and 1.36-fold lower than that of the original sdAb, respectively. The computer simulation analysis indicated that the hydrogen bond, hydrophobic interaction, and side chain steric hindrance of amino acid residues are critical for the binding affinity of the AOA-sdAb. Overall, the techniques shown in this study are effective ways at 'identifying residues involved in antigen binding' that can be altered by site-directed mutation.

2.
Anal Chem ; 92(6): 4639-4646, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32091879

RESUMO

Enzyme-triggered in situ chromogenic and/or fluorogenic reactions under accessible conditions are significant for developing enzyme activity and related spectroscopic assays. Here, we describe a facile one-pot synthetic strategy to prepare silicon-containing nanoparticles with yellow-green fluorescence and orange-red color by mixing N-[3-(trimethoxysilyl)propyl]ethylenediamine and p-aminophenol (AP) in aqueous solution at a mild temperature. Encouraged by the AP-regulated simple synthetic procedure and the generation of AP from alkaline phosphatase (ALP)-catalyzed hydrolysis of 4-aminophenol phosphate (APP), a fluorometric and colorimetric dual-readout ALP activity assay can be rationally envisioned and developed by employing APP as the substrate. In the wake of the good analytical performance of such ALP activity assay and its successful combination with enzyme-linked immunosorbent assay (ELISA), corresponding fluorometric and colorimetric dual-readout ALP-based ELISA has been constructed for highly sensitive and quantitative determination of human prostate-specific antigen (PSA), the key biomarker of prostate cancer in human serum. The convincing performance in evaluating the PSA level in serologic tests unambiguously reveals the great potential of our proposed fluorometric and colorimetric dual-channel immunoassay in early clinical diagnosis by monitoring disease biomarkers.

3.
Mikrochim Acta ; 187(2): 115, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919598

RESUMO

Core-shell palladium cube@CeO2 (Pd cube@CeO2) nanoparticles are shown to display oxidase-like activity. This is exploited in a method for determination of the activity of alkaline phosphatase (ALP). The Pd cube@CeO2 nanoparticles were thermally synthesized from Ce(NO3)3, L-arginine and preformed Pd cube seeds in water. The Pd cube@CeO2 nanoparticles catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by oxygen. This results in the formation of oxidized TMB (oxTMB) with an absorption peak at 652 nm. Ascorbic acid (AA) is generated from the hydrolysis of L-ascorbic acid 2-phosphate (AAP) catalyzed by ALP. It can reduce oxTMB to TMB, and this results in a decrease of the absorbance. The method allows for quantitative determination of the activity of ALP in the range from 0.1 to 4.0 U·L-1 and with a detection limit down to 0.07 U·L-1. Endowed with high sensitivity and selectivity, the assay can quantify ALP activity in biological system with satisfactory results. Graphical abstractSchematic illustration of Pd cube@CeO2 core-shell nanoparticles for colorimetric determination of alkaline phosphatase.

4.
ISA Trans ; 97: 448-457, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31653405

RESUMO

Accurate Li-ion battery modeling is integral to the design of effective battery management systems in electric vehicles. However, the voltage-current (U-I) characteristic of Li-ion batteries presents strong nonlinearity. The application of fractional-order models to create lower-order models to represent physical systems (e.g., the battery characteristics for the state of charge estimation) is interesting and timely. In this paper, a novel fractional variable-order equivalent circuit model (FVO-ECM) is proposed to represent the nonlinear U-I characteristic of Li-ion batteries; its parameter identification is achieved and verified by charge and discharge tests. Compared with the integral-order equivalent circuit model and the fractional constant-order model, the proposed FVO-ECM can identify battery nonlinear characteristics most accurately.

5.
Bull Environ Contam Toxicol ; 104(1): 149-155, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31784766

RESUMO

This study was intended to develop an environment-friendly controlled release system for spirotetramat in an alginate matrix. Four formulations, starch-chitosan-calcium alginate (SCCA), starch-calcium alginate (SCA), chitosan-calcium alginate (CCA), and calcium alginate (CA) complex gel beads, were prepared by the extrusion-exogenous gelation method. The properties of the formulations were studied. The results showed that the release behaviors of the formulations in water could be well described by the logistic model, and the release occurred through Fickian diffusion. Among the four formulations, SCCA showed the highest entrapment efficiency, drug loading and the slowest release rate. Degradation studies revealed that the SCCA formulation exhibited an obvious slower degradation rate of spirotetramat in soils than the commercially available formulation. The estimated half-life of the SCCA formulation was 2.31, 3.25, and 4.51 days in waterloggogenic paddy soil, purplish soil, and montmorillonite, respectively, when the soils were moistened to 60% of its dry weight. This study provided a possible approach to prolong the duration of spirotetramat and to reduce environmental contamination.


Assuntos
Alginatos/química , Compostos Aza/química , Quitosana/química , Compostos de Espiro/química , Bentonita , Preparações de Ação Retardada , Ácido Glucurônico , Ácidos Hexurônicos , Amido
6.
Pest Manag Sci ; 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31828964

RESUMO

BACKGROUND: The chiral pesticide bromothalonil is widely used to control anthracnose disease on fruits and vegetables in China. The pesticidal activity, ecotoxicological effects and environmental behavior of bromothalonil and its enantiomers are still unclear. RESULTS: Bromothalonil presented effective biocidal activities against the tested fungi, its enantiomers showed distinct inhibitory activities against different fungal species. The bioactivities of (+)-bromothalonil was 1.29-10.77 times higher than (-)-bromothalonil toward Rhizoctonia solani, Botrytis cinerea, Curvularia lunata, Corynespora cassiicola, Colletotrichum siamense, and Colletotrichum musae, while the effect pattern was opposite for Colletotrichum cliviicola. Based on the acute toxicity test, bromothalonil was very toxic to Eisenia foetida (E. foetida). Bromothalonil also damaged the lysosomal membrane and exhibited potential genotoxicity toward E. foetida. Moreover, (+)-bromothalonil presented lower toxicity than (-)-bromothalonil. Stereoselective degradation was investigated in tomato, cucumber, chieh-qua, and soil. The half-life values of bromothalonil degradation ranged from 7.14 to 24.75 days, indicating that bromothalonil was easily degraded. Additionally, (+)-bromothalonil degraded 1.2-1.75 times faster than (-)-bromothalonil in the four matrices. CONCLUSION: This is the first systemic assessment of the stereoselectivity of bromothalonil. Based on the obtained half-life, EC50 and LC50 values, bromothalonil is an easily degraded, broad-spectrum biocidal but very toxic pesticide. (+)-Bromothalonil was more degradable in vegetables and soil and showed clearly higher bioactivity toward target organisms and lower toxicity to E. foetida than (-)-bromothalonil. Therefore, the stereoselectivity of bromothalonil enantiomers should be fully considered in comprehensive environmental and ecological risk assessments in future work. © 2020 Society of Chemical Industry.

7.
ACS Appl Mater Interfaces ; 11(50): 47564-47570, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31762263

RESUMO

Enzyme-like activity and efficiency of nanomaterials are strongly controlled by their size, composition, and structure, and hence the structural parameters need to be optimized. Here, we report that two-dimensional Pd nanoplates enclosed by {100}-facets [{100}PdSP@rGO] exhibit substantially enhanced intrinsic oxidase-like activities relative to the {111}-facets ones and Pd nanocubes in catalyzing the chromogenic reaction of 3,3',5,5'-tetramethylbenzidine. By taking ascorbic acid 2-phosphate as the substrate, which transforms to ascorbic acid in the presence of acid phosphatase (ACP), the {100}PdSP@rGO could be used as an efficient nanozyme for colorimetric ACP detection without resorting to destructive H2O2. A good linear relationship from 0.01 to 6.0 mU/mL with a detection limit of 8.3 µU/mL is obtained, which is better than most previously reported ACP assays. Importantly, the excellent assay performance could be successfully applied to ACP determination in serum samples with high accuracy. This study demonstrates that the enzyme-like activity of nanomaterials could be finely tuned simultaneously by controlling their exposed crystal facets and high specific surface area.

8.
IEEE Trans Cybern ; 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31765324

RESUMO

This article is concerned with the problem of distributed prescribed finite-time observer design for a strict-feedback nonlinear system with external disturbance. The purpose is to reconstruct the unavailable system state based on a group of distributed observers, where each of them can only receive at most 1-D output measurement from the system. First, in the absence of disturbance, a new distributed prescribed finite-time observer featuring time-varying gains is constructed and designed under the assumption of joint observability. It is analytically proved that for any prescribed instant independent of system initial conditions and other design parameters, the obtained distributed observer can guarantee not only the asymptotic convergence to zero of the state error between each observer state and the system state at this prescribed instant but also the definite zero-state error after this prescribed instant. Second, a distributed prescribed finite-time bounded observer is delicately proposed to account for the presence of external disturbance in the system dynamics. It is shown that the state error can be bounded by an arbitrarily positive constant after a prescribed instant. Finally, a numerical example and an electromechanical system are presented to demonstrate the effectiveness of the proposed results.

9.
Anal Chem ; 91(23): 15017-15024, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31698900

RESUMO

Phosphate-containing metabolites and alkaline phosphatase (ALP) activity are useful biomarkers for many types of diseases. However, there are few straightforward, sensitive, and efficient colorimetric methods for the quantification of them only when resorting to unstable transition metal ions or specially designed organic substrates. Herein, we have demonstrated that histidine-protected gold nanoclusters (His-AuNCs) possess intrinsic peroxidase-like activity with Au atom facilitated formation of superoxide anions (O2•-) and their electron transfer ability. More interestingly, phosphate-containing metabolites can severely inhibit the peroxidase-like activity of His-AuNCs by blocking the generation of O2•- and electron transfer, and then ALP is able to restore the inhibition process through hydrolyzing the phosphate-containing metabolites. Therefore, using peroxidase-triggered chromogenic reaction of 3,3',5,5'-tetramethylbenzidine (TMB) as an amplifier, a colorimetric on-off-on switch has been developed for sensing phosphate-containing metabolites and ALP based on the logical regulation of such deactivation and reactivation processes for the first time. According to the intrinsic mimic enzyme-catalyzed amplification and clear response mechanism, our colorimetric assay exhibits excellent sensitivity, selectivity, and sensing performance. Furthermore, on the basis of the proposed colorimetric sensors, a combinatorial "NOR+IMPLICATION" logic gate is further rationally constructed.

10.
ISA Trans ; 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31522817

RESUMO

In this paper, novel state feedback and output feedback control strategies are proposed to regulate a class of uncertain time-varying nonholonomic systems with lower-triangular nonlinearities. The nonlinearities admit an incremental rate depending on an unknown parameter and an essential time-varying function. By means of the input-state-scaling technique, the involved systems are firstly transformed into a class of lower-triangular systems. The time-varying high-gain method is then introduced to tackle the system uncertainties and essential time-varying features simultaneously, and based on this, the time-varying state feedback controllers are constructed to achieve the state feedback regulation of the involved systems. Finally a time-varying high-gain observer is proposed to effectively compensate for system uncertainties and essential time-varying features, and on the basis of this, the time-varying output feedback controllers are constructed to achieve the output feedback regulation of the involved systems. Two illustrative examples are provided to demonstrate the effectiveness of the proposed control strategies.

11.
J Diabetes Complications ; 33(9): 623-627, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31255433

RESUMO

AIMS: This cross-sectional study aimed to investigate the association between arterial stiffness and chronic kidney disease (CKD) in Chinese patients with type 2 diabetes mellitus (T2DM). METHODS: This study included 1025 patients with T2DM (796 men, 229 women). The cardio-ankle vascular index (CAVI) served as an index to evaluate arterial stiffness. CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2 and/or urinary albumin-creatine ratio ≥ 30 mg/g. Increased CAVI was defined as a value ≥9. RESULTS: The mean CAVI was 8.4 ±â€¯1.2. Among the patients, 314 (40%) had increased CAVI and 229 (22.3%) had CKD. Blood pressure, HbA1c levels, total cholesterol, low-density lipoprotein cholesterol, uric acid and CAVI were higher among patients with CKD than among those without CKD. Patients with increased CAVI were at a 1.82-fold (95% CI, 1.20-2.75; P < 0.001) higher prevalence of CKD after adjusting for other variables. The odds ratio for CKD was 2.69 (95% CI, 1.12-6.47; P = 0.027) in women and 1.62 (95% CI, 1.01-2.61; P = 0.045) in men. CONCLUSION: Increased CAVI was independently associated with CKD in patients with T2DM. Further longitudinal studies with large sample sizes are warranted to investigate the effect of CAVI on CKD in patients with T2DM.

12.
Antonie Van Leeuwenhoek ; 112(7): 1095-1104, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30725325

RESUMO

Rubber anthracnose caused by Colletotrichum gloeosporioides leads to huge economic loss in the natural rubber industry every year. Conidia of C. gloeosporioides are a major infection source but little is known about molecular mechanisms underlying conidial development and infection. In this study, the C. gloeosporioide C2H2 zinc-finger protein transcription factor gene CgAzf1 is shown to be involved in melanin production, conidial development and infection. Deletion of CgAzf1 resulted in decreased melanin production and hydrophilicity of aerial mycelium was increased. The mutants also showed reduced conidiation, low germination rate, and the formation of appressorium lagged too. Virulence assays showed that the CgAzf1 deletion strain could not infect intact rubber tree leaves and had an attenuated virulence on the wounded leaves. Quantitative RT-PCR showed that CgAzf1 regulates expression of genes involved in the MAPK, cAMP-PKA and melanin biosynthesis pathways.


Assuntos
Colletotrichum/metabolismo , Colletotrichum/patogenicidade , Proteínas Fúngicas/metabolismo , Hevea/microbiologia , Melaninas/metabolismo , Doenças das Plantas/microbiologia , Esporos Fúngicos/crescimento & desenvolvimento , Fatores de Transcrição/metabolismo , Colletotrichum/genética , Colletotrichum/crescimento & desenvolvimento , Proteínas Fúngicas/genética , Micélio/química , Micélio/genética , Micélio/metabolismo , Micélio/patogenicidade , Filogenia , Esporos Fúngicos/genética , Esporos Fúngicos/metabolismo , Esporos Fúngicos/patogenicidade , Fatores de Transcrição/genética , Virulência
13.
Food Addit Contam Part B Surveill ; 12(1): 1-9, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30052129

RESUMO

Phthalate esters (PAEs) have attracted much attention because of their ubiquity and toxicity. However, previous studies mainly focused on the occurrence of PAEs controlled by the Environmental Protection Agency and neglected most uncontrolled PAEs. In this study, the occurrence of 21 PAEs, including 6 controlled and 15 uncontrolled PAEs, was investigated in polyethylene terephthalate (PET)-bottled drinking water samples purchased from markets in Beijing. Seventeen PAEs were detected in all samples, with dibutyl phthalate, diisobutyl phthalate, and dimethyl phthalate as the predominant compounds. Correlation analysis suggested that PET bottles might be one of the potential sources of PAEs in PET-bottled drinking water. The human health risks assessments indicated little or no risks from four controlled PAEs in bottled water. In comparison, the risks of uncontrolled PAEs should be of greater concern for their ubiquities in bottled drinking water.


Assuntos
Exposição Dietética/análise , Água Potável/química , Contaminação de Alimentos/análise , Embalagem de Alimentos/instrumentação , Ácidos Ftálicos/análise , Polietilenotereftalatos , Pequim , Carcinógenos/análise , China , Dibutilftalato/análogos & derivados , Dibutilftalato/análise , Ésteres/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Ácidos Ftálicos/efeitos adversos , Fatores de Risco , Extração em Fase Sólida , Espectrometria de Massas em Tandem
14.
IEEE Trans Cybern ; 49(6): 2133-2143, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29993859

RESUMO

This paper addresses the finite-time H∞ filtering for a class of nonlinear singular nonhomogeneous Markov jump systems by T-S fuzzy approximation approach, where the transition probabilities (TPs) are time-varying and unknown. First, by considering a stochastic Lyapunov functional and rendering the time-varying TPs inside a polytope, a sufficient condition on singular stochastic H∞ finite-time boundedness (SS H∞ FTB) for the filtering error systems is given. Then, by using the matrix inequality decoupling technique, a novel linear matrix inequality (LMI) condition on the existence of the finite-time H∞ fuzzy filter is presented. The fuzzy filter is developed in terms of LMIs ensuring the filtering error system is SS H∞ FTB. Compared with the previous ones, the proposed design method in this paper has more freedom, leading to less conservative results. A tunnel diode circuit is provided to illustrate the effectiveness and advantage of the design approach proposed in this paper.

15.
J Diabetes ; 11(6): 440-448, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30318734

RESUMO

BACKGROUND: Type 1 diabetes (T1D) is an autoimmune disease resulting from an attack by autoreactive T lymphocytes against pancreatic islet ß- cells. In recent studies, regulatory T cells (Tregs) have been implicated in the process of T1D. Furthermore, cluster of differentiation 39 (CD39), which is involved in the suppression of inflammation, has been shown to be expressed on Tregs. However, the pathological importance of CD39 to the memory Treg population remains unclear. METHODS: This study investigated Treg subsets, focusing on resting, effector, and memory Tregs, and determined CD39 expression on Tregs. In addition, changes in Treg subsets and Treg-associated cytokine secretion after CD3/CD28 stimulation of peripheral blood mononuclear cells were evaluated in diabetic patients and healthy controls. The suppressive function of Tregs was measured using the mixed lymphocyte reaction (MLR) test. RESULTS: There was a higher percentage of memory Tregs in T1D patients than healthy controls. However, Tregs in T1D patients showed impaired suppression, with low forkhead box P3 (Foxp3) expression and low serum interleukin (IL)-10 levels. Furthermore, CD39 expression on Tregs, and on memory Tregs in particular, was lower in T1D patients than healthy controls. After stimulation, the percentage of resting Tregs was decreased and that of effector/memory Tregs was increased in both healthy controls and T1D patients, but CD39 expression on effector/memory Tregs was still lower and there was no increase in IL-10 secretion in T1D patients. CONCLUSIONS: The defective suppressive function of Tregs in T1D patients is due to lower expression of CD39 on memory Tregs.


Assuntos
Apirase/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Memória Imunológica/imunologia , Leucócitos Mononucleares/metabolismo , Linfócitos T Reguladores/metabolismo , Adulto , Biomarcadores/análise , Glicemia/análise , Estudos de Casos e Controles , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/patologia , Feminino , Seguimentos , Fatores de Transcrição Forkhead/metabolismo , Hemoglobina A Glicada/análise , Humanos , Interleucina-10/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia
16.
Nat Commun ; 9(1): 5236, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30531797

RESUMO

The widespread use of proton exchange membrane water electrolysis requires the development of more efficient electrocatalysts containing reduced amounts of expensive iridium for the oxygen evolution reaction (OER). Here we present the identification of 6H-phase SrIrO3 perovskite (6H-SrIrO3) as a highly active electrocatalyst with good structural and catalytic stability for OER in acid. 6H-SrIrO3 contains 27.1 wt% less iridium than IrO2, but its iridium mass activity is about 7 times higher than IrO2, a benchmark electrocatalyst for the acidic OER. 6H-SrIrO3 is the most active catalytic material for OER among the iridium-based oxides reported recently, based on its highest iridium mass activity. Theoretical calculations indicate that the existence of face-sharing octahedral dimers is mainly responsible for the superior activity of 6H-SrIrO3 thanks to the weakened surface Ir-O binding that facilitates the potential-determining step involved in the OER (i.e., O* + H2O → HOO* + H+ + e¯).

17.
ChemSusChem ; 11(24): 4209-4213, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30346658

RESUMO

The fast and living ring-opening polymerization (ROP) of propylene oxide (PO) by metal-free catalysis is reported. By using triethyl borane (TEB) and organic Lewis bases (LBs, e.g.: phosphazene base, amidine and guanidine) as the catalysts, various alkyl alcohols can effectively initiate the ROP of PO, yielding tailor-made poly(propylene oxide)s (PPOs) with high regioregularity, predictable molecular weights, and narrow dispersity approaching Poisson distribution. The TEB/LB catalysts present unprecedentedly high activity (turnover frequency of up to 7500 h-1 ) and a truly living character for the polymerization, as evidenced by kinetic studies that showed fast initiation and growth, unobserved chain-transfer to PO, chain extension reactions, and the synthesis of various PPO-based block copolymers with narrow dispersities (D<1.1).

18.
Phys Chem Chem Phys ; 20(20): 13757-13764, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29740655

RESUMO

Using density functional theory (DFT) calculations, we have comprehensively investigated the structure and the hydrogen evolution reaction (HER) catalytic activity for pristine and monovacancy defected WP systems. It was revealed that the (101) surface can have the most exposure for the WP structure. The calculated free energy values of H* (ΔGH*) show that the (101) surface can exhibit good HER catalytic activity, where the top site over the W atoms can act as the most active site for HER due the existence of antibonding characteristics after adsorbing H*. Moreover, we have proposed an effective strategy through the introduction of a monovacancy to further improve the HER activity of the WP system. It was found that the formation of the W-monovacancy can significantly improve HER activity since the decreased coordination number of the correlative atoms brings some new active sites around the defect. Particularly, these systems can even exhibit considerably high HER activity over a wide range of hydrogen coverage. Clearly, all these fascinating findings at the atomic level can be beneficial for realizing highly efficient nonprecious HER electrocatalysts based on tungsten phosphide and even other transition metal phosphides in the near future.

19.
Phys Chem Chem Phys ; 20(22): 15424-15433, 2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29796571

RESUMO

Inorganic boron nitride (BN) nanomaterials possess outstanding physical and chemical characteristics, and can be considered as an excellent building block to construct new composite nanomaterials. In this work, on the basis of the first-principles computations, a new type of composite nanostructure can be constructed by depositing superhalogen Al13 on the surface of low-dimensional BN monolayer or nanoribbons (BNML/BNNRs). All these Al13-modified BN nanosystems can possess large adsorption energies, indicating that superhalogen Al13 can be stably adsorbed on the surface of these BN materials. In particular, it is revealed that independent of the chirality, ribbon width and adsorption site, introducing superhalogen Al13 can endow the BN-based composite systems with a magnetic ground state with a magnetic moment of about 1.00 µB, and effectively narrow their robust wide band gaps. These new superhalogen-Al13@BN composite nanostructures, with magnetism and an appropriate band gap, can be very promising to be applied in multifunctional nanodevices in the near future.

20.
Chemistry ; 24(29): 7480-7488, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29577467

RESUMO

Ionic porous organic polymers have attracted much attention due to their broad applications in catalysis, energy storage/conversion, proton conduction, etc. In this paper, an ionic porous organic polymer, CMP-PM-Me, was synthesized through post-synthetic modification of a pyrimidine-based conjugated microporous polymer, CMP-PM, which was constructed by the palladium catalyzed Sonogashira reaction of 1,3,5-triethynylbenzen and 2,5-dibromopyrimidine. These two polymers are porous with Brunauer-Emmett-Teller surface areas of 416 and 241 m2 g-1 for CMP-PM and CMP-PM-Me, respectively. Due to the cationic framework, CMP-PM-Me exhibits a much faster and more efficient adsorption performance to anionic dyes such as Congo red (CR) and methyl orange (MO) than that of CMP-PM with a neutral framework. The uptakes for CR are 400.0 mg g-1 for CMP-PM-Me and 344.8 mg g-1 for CMP-PM, respectively. Furthermore, CMP-PM-Me could quickly and drastically separate anionic dyes from the binary mixed solution of anionic and nonanionic dyes within a short time. This work not only enriches the family of ionic organic porous polymers and widens their synthetic utility, but also demonstrates their applications in the adsorption and separation of anionic dyes in water.

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