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1.
Molecules ; 29(17)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39275050

RESUMO

This paper presents a composed lithium phosphate (LiPON) solid electrolyte interface (SEI) film which was coated on a lithium electrode via an electrodeposit method in a lithium-sulfur battery, and the structure of the product was characterized through infrared spectrum (IR) analysis, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), environment scanning electron microscope (ESEM), etc. Meanwhile, the electrochemical impedance spectrum and the interface stability of the lithium electrode with the LiPON film was analyzed, while the coulomb efficiency and the cycle life of the lithium electrode with the LiPON film in the lithium-sulfur battery were also studied. It was found that this kind of film can effectively inhibit the charge from transferring at the interface between the electrode and the solution, which can produce a more stable interface impedance on the electrode, thereby improving the interface contact with the electrolyte, and effectively improve the discharge performance, cycle life, and the coulomb efficiency of the lithium-sulfur battery. This is of great significance for the further development of solid electrolyte facial mask technology for lithium-sulfur batteries.

2.
Anal Bioanal Chem ; 415(1): 211-220, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36342508

RESUMO

As an emerging neurodegenerative disease, Alzheimer's disease (AD) has become a leading cause of dementia in older adults. Visinin-like protein-1 (VILIP-1) is an increasingly used biomarker for AD besides the widely accepted Aß1-40, Aß1-42, and tau. However, significant variations exist in the commercial immuno-based assays for VILIP-1 quantification, underlining the necessity to establish a traceability chain. Certified reference materials (CRMs) located at the top of the traceability chain are traceability sources for relevant matrix standard materials. In this work, VILIP-1 solution CRM with a certified value and uncertainty of 39.82±1.52 µg·g-1 was developed and certified using amino acid-based isotope dilution mass spectrometry (AA-ID-MS) and sulfur-based isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS). Certified values from both strategies showed great consistency, with traceability to SI units. Moreover, the candidate VILIP-1 CRM shows excellent homogeneity and can be stable for at least 7 days at -20°C and 12 months at -70°C. The VILIP-1 CRM developed can be used in value assignment to secondary calibrators and clinical matrix CRMs, showing prospects in early diagnosis and disease monitoring for AD.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Idoso , Neurocalcina , Aminoácidos/análise , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Doença de Alzheimer/diagnóstico , Enxofre , Isótopos , Padrões de Referência
3.
Anal Chem ; 94(34): 11753-11759, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35977378

RESUMO

Accurate and traceable measurement of hemoglobin (HGB) is of great importance in clinical testing. Although the HiCN method is the internationally accepted conventional reference method for this biomarker and frequently used in clinical routine diagnostics, the HiCN method cannot be traceable to the International System of Units (SI) and thus does not meet highest metrological demands. In this study, an absolute quantitative approach for total HGB in a whole blood sample is proposed based on the determination of natural Fe and S present in the heme-group of HGB by HPLC isotope dilution ICP-MS. IRMM/IFCC-467 is used for method validation, and then clinical blood samples are measured by the established strategy and HiCN method. The measurable ranges of total HGB were 10.0-240.0 g L-1. Limits of detection via Fe and S were 0.01 and 0.07 g L-1, respectively. The intra-assay imprecision CVs via Fe and S were 0.89-1.35 and 0.99-1.56%, and the interassay CVs were 1.19-2.15 and 1.55-2.55%, respectively. Good agreement was achieved in the method validation. In the comparison with HiCN experiments, the ID-ICP-MS assays via Fe and S showed correlations of r2 = 0.991 and 0.970 against HiCN methods. Moreover, the concentration of transferrin (Tf) was also simultaneously measured. This strategy has potential to serve as a reference measurement procedure for total HGB in whole blood, which could be traceable to SI and does not require toxic derivation reagent.


Assuntos
Hemoglobinas , Isótopos , Cromatografia Líquida de Alta Pressão/métodos , Técnicas de Diluição do Indicador , Espectrometria de Massas/métodos
4.
Int J Mol Sci ; 23(8)2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35457097

RESUMO

Two key concerns exist in contemporary cancer chemotherapy: limited therapeutic efficiency and substantial side effects in patients. In recent years, researchers have been investigating the revolutionary cancer treatment techniques of photodynamic therapy (PDT) and photothermal therapy (PTT) proposed by many scholars. A photothermal treatment of cancer was synthesized using the hydrothermal method which has high photothermal conversion efficiency and can generate reactive oxygen species (ROS) in cells. Photothermal treatment of tumors has a good short-term effect and photodynamic therapy lasts longer. However, both PTT and PDT have their inevitable shortcomings and it is difficult to completely eradicate a tumor using a single mode of treatment. PTT and PDT synergistic treatment not only inherits the advantages of low toxicity and side effects of phototherapy but also enables the two treatment methods to complement each other. It is an effective strategy to improve curative effects and reduce toxic and side effects. Furthermore, gold doped UCNPs have an exceptionally high target recognition for tumor cells. The gold doped UCNPs, in particular, are non-toxic to normal tissues, endowing the as-prepared medications with outstanding therapeutic efficacy and exceptionally low side effects. These findings may encourage the creation of fresh, effective imaging-guided approaches to meet the goal of photothermal cancer therapy.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Nanoestruturas , Neoplasias , Fotoquimioterapia , Ouro/farmacologia , Humanos , Nanopartículas Metálicas/uso terapêutico , Neoplasias/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fototerapia
5.
Int J Mol Sci ; 23(3)2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35163306

RESUMO

Two key concerns exist in contemporary cancer chemotherapy in clinics: limited therapeutic efficiency and substantial side effects in patients. In recent years, researchers have been investigating revolutionary cancer treatment techniques and photo-thermal therapy (PTT) has been proposed by many scholars. A drug for photothermal cancer treatment was synthesized using the hydrothermal method, which has a high light-to-heat conversion efficiency. It may also be utilized as a clear multi-modality bioimaging platform for photoacoustic imaging (PAI), computed tomography (CT), and magnetic resonance imaging (MRI). When compared to single-modality imaging, multi-modality imaging delivers far more thorough and precise details for cancer diagnosis. Furthermore, gold-doped upconverting nanoparticles (UCNPs) have an exceptionally high target recognition for tumor cells. The gold-doped UCNPs, in particular, are non-toxic to normal tissues, endowing the as-prepared medications with outstanding therapeutic efficacy but exceptionally low side effects. These findings may encourage the creation of fresh effective imaging-guided approaches to meet the goal of photothermal cancer therapy.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Imagem Multimodal/métodos , Fototerapia/métodos , Animais , Linhagem Celular Tumoral , Terapia Combinada/métodos , Liberação Controlada de Fármacos/fisiologia , Feminino , Células HeLa , Humanos , Nanopartículas Metálicas/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Nanoestruturas/química , Neoplasias/tratamento farmacológico , Técnicas Fotoacústicas/métodos
6.
Int J Mol Sci ; 23(3)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35163150

RESUMO

Two key concerns exist in contemporary cancer chemotherapy in clinic: limited therapeutic efficiency and substantial side effects in patients. In recent years, researchers have been investigating a revolutionary cancer treatment technique, and photodynamic therapy (PDT) has been proposed by many scholars. A drug for photodynamic cancer treatment was synthesized using the hydrothermal method, which has a high efficiency to release reactive oxygen species (ROS). It may also be utilized as a clear multi-modality bioimaging platform for photoacoustic imaging (PAI) due to its photothermal effect, computed tomography (CT), and magnetic resonance imaging (MRI). When compared to single-modality imaging, multi-modality imaging delivers far more thorough and precise details for cancer diagnosis. Furthermore, Au-doped up-conversion nanoparticles (UCNPs) have an exceptionally high luminous intensity. The Au-doped UCNPs, in particular, are non-toxic to tissues without laser at an 808 nm wavelength, endowing the as-prepared medications with outstanding therapeutic efficacy but exceptionally low side effects. These findings may encourage fresh effective imaging-guided approaches to meet the goal of photodynamic cancer therapy to be created.


Assuntos
Ouro/química , Nanopartículas Metálicas/administração & dosagem , Imagem Multimodal/métodos , Fotoquimioterapia/métodos , Nanomedicina Teranóstica , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Apoptose , Proliferação de Células , Feminino , Humanos , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Técnicas Fotoacústicas/métodos , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Anal Chem ; 92(19): 13229-13237, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32847351

RESUMO

The use of amyloid-beta (Aß) biomarkers could contribute to an early diagnosis of Alzheimer's disease (AD); however, there are still large variations among results from different assays. This variability can be overcome by standardization of those assays through the use of certified reference materials (CRMs) and the establishment of a traceability chain. In this study, Aß40 (GBW09874) and Aß42 (GBW09875) solution CRMs with the certified values and uncertainties of 7.58 ± 0.30 and 7.62 ± 0.30 µg g-1 were developed with high-purity Aß as raw materials. For the first time, isotope dilution high-performance liquid chromatography mass spectrometry (ID-LC-MS) and high-performance liquid chromatography isotope dilution inductively coupled plasma mass spectrometry (HPLC-ID-ICP-MS) strategies were employed to certify the candidate Aß solution CRMs. The two candidate CRMs showed good homogeneity, and good stability was also demonstrated for at least 5 days at -20 °C and 14 months at -70 °C. These CRMs are primarily intended to be used for value assignment to secondary calibrators or CRMs with a clinical matrix, which will help in early diagnosis of AD.


Assuntos
Aminoácidos/química , Peptídeos beta-Amiloides/análise , Técnicas de Diluição do Indicador , Cromatografia Líquida de Alta Pressão , Humanos , Espectrometria de Massas
8.
J Sep Sci ; 38(10): 1700-10, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25755215

RESUMO

Phthalate esters are additives used in polyvinylchloride and are found as contaminants in many food products. An isotope dilution mass spectrometry technique has been developed for accurate analysis of 16 phthalate esters in Chinese spirits by adopting the 16 corresponding isotope-labeled phthalate esters. The ethanol in the spirit sample was first removed by heating with a water bath at 100°C with a stream of nitrogen, after which the residue was extracted with n-hexane twice. The phthalates collected were identified and quantified by gas chromatography with tandem mass spectrometry in multiple reaction monitoring mode. The spiking recoveries of 16 analytes ranged from 94.3 to 105.3% with relative standard deviation values of <6.5%. The detection limits for 16 analytes were <10.0 ng/g. The expanded relative uncertainties were from 3.0 to 14%. A survey was performed on Chinese spirits from the market. Six of the nine analyzed samples were contaminated by phthalates. Di-n-butyl phthalate and di-2-ethylhexyl phthalate showed higher detection frequency and concentrations. This isotope dilution gas chromatography with tandem mass spectrometry method is simple, rapid, accurate, and highly sensitive, which qualifies as a candidate reference method for the determination of phthalates in spirits.

9.
Nanoscale ; 14(45): 16986-16993, 2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36354382

RESUMO

Aqueous lithium-ion batteries (LIBs) have attracted increasing attention because of their higher safety and nontoxicity compared to traditional LIBs. However, crucial shortcomings impede their practical applications. A narrow electrochemical window restricts the capacity of aqueous LIBs so the ultrahigh concentration electrolyte lithium bistrifluoromethosulfonimide (LiTFSI) is introduced to widen the electrochemical window in this work. With the addition of LiTFSI, the electrochemical window of the created aqueous LIBs is improved to 2 V. Moreover, the material design promotes the high density of aqueous LIBs, in which hollow Co3O4 nanocrystals obtained by the metal organic framework (MOF) template are connected with NiCo2O4 nanorods to form three-dimensional nanohybrids. The formed Co3O4/NiCo2O4 (CN) materials can provide NiCo2O4 channels for electron transfer between hollow Co3O4 which can offer more lithium-ions insertion. These effects work together synergistically to achieve aqueous LIBs with a wide electrochemical window and high energy density (93.07 W h kg-1 at 0.5 C). CN-6/LiMn2O4-based aqueous LIBs with LiTFSI as the electrolyte take into account both environmental friendliness and sustainable energy storage and exhibit great potential for producing novel clean energy storage devices from the concepts of material design and synthesis.

10.
Nanomaterials (Basel) ; 12(5)2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35269216

RESUMO

In this study. a novel near-infrared fluorescent-driven contrast agent (Ag-doped NaYF4:Yb3+/Er3+@NaYF4:Nd3+@NaGdF4) was synthesized using a coprecipitation-hydrothermal-solvothermal-solvothermal (CHSS) method. The results shows that hexagonal NaYF4:Yb3+/Er3+ with a diameter of 300 nm was successfully synthesized by the CHSS method. The new contrast agent was characterized using scanning electron microscopy, fluorescence spectrometry, transmission electron microscopy, energy-dispersive spectrometry and ultraviolet-visible light diffuse reflectance absorption spectroscopy. Even at low concentrations (0.2 M), this proposed contrast agent can be excited by near-infrared light with a wavelength of 980 nm and emits a dazzling green light with a wavelength of 540 nm, and the comparison of the luminescence intensity proves that doping with silver increases the luminescence intensity of the upconverted nanomaterial by nearly 13 times based on the calculated quantum yield. TEM images show the successful preparation of silver nanoparticles with a diameter of 30 nm, and the energy spectrum shows the successful doping of silver nanoparticles and the successful preparation of the core-shell structure of NaYF4:Yb3+/Er3+@NaYF4:Nd3+@NaGdF4. Furthermore, the mechanism of the increased luminous intensity has been studied using simulation calculations. Finally, cytotoxicity tests were used to test material which was modified by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG2K), and the biocompatibility was significantly improved, meeting the standard for biological applications.

11.
Materials (Basel) ; 15(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36499862

RESUMO

This paper presents an investigation of the modification of natural oxazines to traditional bisphenol A benzoxazines. Eugenol was reacted with furfurylamine to synthesize a new type of benzoxazine (eugenol-furfurylamine benzoxazine), with a yield of 77.65%; and another new type of benzoxazine (bisphenol A-furfurylamine benzoxazine) was generated from bisphenol A and furfurylamine, with the highest yield of 93.78%. In order to analyze and study the target molecules, IR (infrared radiation) spectroscopy, GPC (gel-permeation chromatograph), mass spectrometry, 1H-NMR (nuclear magnetic resonance), DSC (differential scanning calorimetry), and DMA (dynamic mechanical analysis) tests were conducted. Eugenol-furfurylamine benzoxazine and conventional bisphenol A-aniline benzoxazine (BZ) composite was also analyzed and cured at different mass ratios of 2:98, 5:95, 10:90, 20:80, and 40:60. When the content of eugenol furfurylamine in the blend reached 5%, the strength of the composite was greatly enhanced, while the strength decreased with the increase in eugenol furfurylamine oxazine content. Moreover, octamaleimide phenyl POSS (OMPS, polyhedral oligomeric silsesquioxane) and bisphenol A furamine benzoxazine were mixed at different molar ratios of 1:16, 1:8, 1:4, 1:2, and 1:1. The curing temperature sharply decreased with the increase in OMPS content. When the molar ratio reached 1:1, the curing temperature decreased from 248 to 175℃. A further advantage of using eugenol and furfurylamine is that they are renewable resources, which is important in terms of utilizing resources effectively and developing environmentally friendly products.

12.
Membranes (Basel) ; 11(7)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209570

RESUMO

We report on the preparation and characterization of a novel lamellar polypyrrole using an attapulgite-sulfur composite as a hard template. Pretreated attapulgite was utilized as the carrier of elemental sulfur and the attapulgite-sulfur-polypyrrole (AT @400 °C-S-PPy) composite with 50 wt.% sulfur was obtained. The structure and morphology of the composite were characterized with infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). An AT @400 °C-S-PPy composite was further utilized as the cathode material for lithium-sulfur batteries. The first discharge specific capacity of this kind of battery reached 1175 mAh/g at a 0.1 C current rate and remained at 518 mAh/g after 100 cycles with capacity retention close to 44%. In the rate test, compared with the polypyrrole-sulfur (PPy-S) cathode material, the AT @400 °C-S-PPy cathode material showed lower capacity at a high current density, but it showed higher capacity when the current came back to a low current density, which was attributed to the "recycling" of pores and channels of attapulgite. Therefore, the lamellar composite with special pore structure has great value in improving the performance of lithium-sulfur batteries.

13.
Materials (Basel) ; 14(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34771965

RESUMO

The preparation and characterization of a polyaniline-silver-sulfur nanotube composite were reported in this paper. The polyaniline-silver nanotube composite was synthesized via an oxidation-reduction method in the sodium dodecyl sulfate (SDS) solution. After being vulcanized, the polyaniline-silver-sulfur (Poly (AN-Ag-S)) nanotube composite was prepared as active cathode material and assembled into lithium-sulfur (Li-S) batteries with electrolyte and negative electrode materials. When the feed ratio of raw materials (aniline and AgNO3) was 2:1, the initial specific capacity of poly (AN-Ag-S) composite cells reached 1114 mAh/g. The specific capacity was kept at 573 mAh/g, and the capacity retention rate stayed above 51% after 100 cycles. The introduction of Ag into the composite cathode material can effectively solve the poor conductivity of sulfur and improve the Li-S battery performance.

14.
Materials (Basel) ; 14(22)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34832167

RESUMO

The thermal decomposition of brominated butyl rubber under air atmosphere was investigated by thermogravimetry (TG) and derivative thermogravimetry (DTG) at various heating rates. The kinetic parameters were evaluated by TG and the isoconversional method developed by Ozawa. One prominent decomposition stage was observed in the DTG curves at high heating rates, while an additional small peak was observed at low heating rates. The apparent activation energy determined using the TG method ranged from 219.31 to 228.13 kJ·mol-1 at various heating rates. The non-isothermal degradation was found to be a first-order reaction, and the activation energy, as determined by the isoconversional method, increased with an increase in mass loss. The kinetic data suggest that brominated butyl rubber has excellent thermal stability. This study can indirectly aid in improving rubber pyrolysis methods and in enhancing the heat resistance of materials.

15.
Biosensors (Basel) ; 11(11)2021 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-34821668

RESUMO

Herein, the Co3O4/NiCo2O4 nanocomposite has been prepared as a novel electrochemical sensor to accurately detect hydrogen peroxide (H2O2) and glucose. ZIF-67 is a metal-organic framework (MOF) with Co as the center metal ion. Co3O4 can be obtained by calcination of ZIF-67 at 700 °C, which can retain the structure of ZIF-67. The hollow Co3O4 nanocrystal was synthesized based on a calcination process of ZIF-67. This open structure can promote the whole Co3O4/NiCo2O4 nanocomposite larger accessible surface area and reactive sites. Co3O4 has good electrocatalytic performance, which has been applied in many fields. Moreover, H2O2 and dopamine sensing tests indicate that the as-prepared non-enzymatic electrochemical biosensor has good detection properties. The testing results indicate the as-prepared biosensor has a wide detection range, low detection limit, high selectivity, and long-term stability. These testing results suggest the potential application in food security, biomedicine, environmental detection, and pharmaceutical analysis.


Assuntos
Dopamina/análise , Peróxido de Hidrogênio , Nanocompostos , Cobalto , Técnicas Eletroquímicas , Peróxido de Hidrogênio/análise , Níquel , Óxidos
16.
Nanomaterials (Basel) ; 11(12)2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34947744

RESUMO

In this study, a new method for synthesizing Ag-NaYF4:Yb3+/Er3+ @ SiO2 nanocomposites was introduced. Using a hydrothermal method, the synthesized Yb3+- and Er3+-codoped NaYF4 up-conversion luminescent materials and Ag nanoparticles were doped into up-conversion nanomaterials and coated with SiO2 up-conversion nanomaterials. This material is known as Ag-UCNPs@SiO2, it improves both the luminous intensity because of the doped Ag nanoparticles and has low cytotoxicity because of the SiO2 coating. The morphology of UCNPs was observed using scanning electron microscopy (SEM), and the mapping confirmed the successful doping of Ag nanoparticles. Successful coating of SiO2 was confirmed using transmission electron microscopy (TEM). Fluorescence spectra were used to compare changes in luminescence intensity before and after doping Ag nanoparticles. The reason for the increase in luminescence intensity after doping with Ag nanoparticles was simulated using first-principles calculations. The cytotoxicity of Ag-UCNPs@SiO2 was tested via the cell counting kit-8 (CCK-8) method, and its imaging ability was characterized using the micro-CT method.

17.
Anal Chim Acta ; 1148: 238197, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33516374

RESUMO

Quantitative imaging of amyloid beta (Aß) in brain is of great significance for pathological study and follow-up drug development of Alzheimer's disease (AD). In this work, a method using antibody-conjugated gold nanoparticles (AuNPs) was established for quantitative imaging of Aß peptide in the brain of AD mouse by Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Aß antibody (Anti-Aß) was labeled with AuNPs to form the conjugate AuNPs-Anti-Aß which was immunoreactive with Aß in the brain slice of mouse. Quantitative imaging of Au was acquired with homogenized brain slice matrix-matched standards as external calibrants which were made by immersing in gold standard solution with different concentrations. Furthermore, the stoichiometric ratios between metal conjugates and Aß were optimized, and the immunoreaction efficiency after labeling was also investigated. According to the molar relationship between AuNPs and Anti-Aß (1:4.3) and the ratio of Anti-Aß to Aß (1:1), quantitative imaging of Aß in brain was accomplished. The method intuitively displayed the location and concentration of Aß aggregation, which was consistent with traditional immunohistochemical staining. Since the numerous gold atoms contained in AuNPs can enhance the signal of Aß, the method is more intuitive and sensitive. The proposed methodology is potential in investigating the quantitative imaging of biomarker heterogeneity, and is useful to understand such complex brain mechanisms in the future.


Assuntos
Doença de Alzheimer , Terapia a Laser , Nanopartículas Metálicas , Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/metabolismo , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Ouro , Camundongos
18.
Artigo em Inglês | MEDLINE | ID: mdl-33348783

RESUMO

The 19th National Congress of the Communist Party of China clearly regards the prevention and control of environmental pollution as one of the "three key battles" to build a well-off society. This paper analyzes the relationship between social capital and environmental pollution from both theoretical and empirical perspectives. From the theoretical perspective, social capital has two opposite effects on environmental pollution: the suppression and the promotion. The former indicates that the improvement of social capital level reduces the cost of residents' boycott to pollution and reduces pollution emissions, while the latter manifests that the improvement of social capital worsens environmental pollution due to the ability of polluting enterprises to withstand residents' boycott. Based on the panel data of China from 2008 to 2016, the empirical results show that social capital has inverted U-shaped characteristics on environmental pollution. Low level of social capital will increase pollution emissions and only when social capital reaches a certain level can it be beneficial to environmental protection. This paper attempts to better understand the functions of social capital in environmental governance and provides constructive proposals on how to exert the governance role of social capital on environmental protection for policy makers. Regions with higher levels of social capital should exert the suppression effect of social capital and regions with low levels should focus on improving the level of social capital, while formal regulation means shall be adopted to control pollution.


Assuntos
Poluição Ambiental , Capital Social , China , Conservação dos Recursos Naturais , Política Ambiental , Poluição Ambiental/estatística & dados numéricos
19.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 7): o1477, 2009 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21582779

RESUMO

The title compound, C(18)H(12)N(2)O, crystallizes in a zwitterionic form. The dihedral angle between the planes of the benzene ring and naphthalene ring system is 13.95 (5)°. An intra-molecular N-H⋯O inter-action results in the formation of a planar six-membered ring, which is oriented at dihedral angles of 13.50 (4) and 4.49 (4)° with respect to the benzene ring and naphthalene ring system, respectively. In the crystal structure, inter-molecular C-H⋯O and C-H⋯N inter-actions link the mol-ecules into a two-dimensional network. π-π contacts between the naphthalene systems [centroid-centroid distance = 3.974 (1) Å] may further stabilize the structure.

20.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 5): o1141, 2009 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-21583948

RESUMO

The mol-ecule of the title compound, C(22)H(26)N(2)O, displays a trans configuration with respect to the C=N double bond. The dihedral angle between the planes of the two aromatic rings is 26.30 (15)°. There is a strong intra-molecular O-H⋯N hydrogen bond between the imine and hydroxyl groups.

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