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1.
Artigo em Inglês | MEDLINE | ID: mdl-34360509

RESUMO

It is the scientific way to promote the transformation and optimization of an industrial structure to promote the improvement of its green total factor productivity (GTFP) by formulating environmental regulation policies. Based on the GTFP panel data of 30 provinces in China from 2004 to 2017, this paper takes the "Air Pollution Control and Prevention Action Plan" (APCP Action Plan) as the proxy dummy variable of environmental regulation, and uses the difference-in-differences (DID) model to explore the impact of the implementation of the APCP Action Plan on GTFP. In addition, by constructing the industrial structure optimization index, this paper analyzes how the APCP Action Plan policy affects GTFP through the transformation and optimization of industrial structure. The following basic conclusions are obtained: First, environmental regulation policies like the APCP Action Plan can improve GTFP. Second, the APCP Action Plan has regional heterogeneity in promoting GTFP in different regions. The policy only significantly affects the GTFP in the Pearl River Delta region in southern China. Third, the "quantity" and "quality" of the optimization of industrial structure will weaken the promoting effect of the APCP Action Plan on GTFP. In contrast, the rationalization of industrial structure will aggravate this promoting effect.


Assuntos
Poluição do Ar , Política Ambiental , Poluição do Ar/prevenção & controle , China , Conservação dos Recursos Naturais , Eficiência , Poluição Ambiental
2.
Waste Manag ; 134: 220-230, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34454188

RESUMO

The heterogeneous Fenton-like process with bimetallic chelated magnetic chitosan aerogel (Cu-Fe@CTS) as catalyst was applied to treat pre-coagulated leachate nanofiltration concentrate. The process conditions were optimized by Box-Behnken Design (BBD) and the maximum UV254 removal reached 96.06% under the conditions of temperature 87.62 °C, oxidant dosage 0.2395 mol/L and catalyst dosage 1 g/L. The TOC concentration was reduced from 847.5 to 99.7 mg/L and COD concentration was reduced from 1625 to 464 mg/L. The three-dimensional (3D) fluorescence analysis showed that most of Fulvic acid-like (FA-like) was removed. The adsorption experiment showed that the catalyst reached the adsorption balanced after 60 min and the corresponding FA adsorption removal reached 14.1%. The addition of Tert-butanol (TBA) reduced the FA removal by 59.4%, indicating that the hydroxyl radicals (OH) was the main active species. Experiments of the OH capture at different pH showed that the Fenton-like system produced more OH at pH of 4, at which the maximum FA removal was 96.61%, while the FA removal still reached 94.26% at pH of 7. The OH capture at different temperature showed that the Fenton-like system produced more OH at 90 °C. KI and TBA shielding experiments showed that OH was produced on the catalyst surface rather than being produced by catalysis of free metal ions in the solution.


Assuntos
Peróxido de Hidrogênio , Poluentes Químicos da Água , Catálise , Ferro , Oxirredução , Poluentes Químicos da Água/análise
3.
Artigo em Inglês | MEDLINE | ID: mdl-34215997

RESUMO

Sandostatin long-acting release® (SLAR) is a long-acting injectable somatostatin analogue formulation composed of octreotide encapsulated in glucose-initiated poly(lactic-co-glycolic acid) (PLGA) microspheres. Despite the end of patent protection, SLAR remains resistant to generic competition likely due to complexity of production process, the uniqueness of the glucose star polymer, and the instability of octreotide in the formulation. Here, we describe development of glucose-PLGA-based composition-equivalent to SLAR formulations prepared by double emulsion-solvent evaporation method and the effect of variations in encapsulation variables on release kinetics and other formulation characteristics. The following encapsulation variables were adjusted at constant theoretical loading of 7.0% peptide: PLGA concentration, pH of inner water phase, and stirring rate. After final drying, the microspheres were examined with and without annealing at 50 °C under vacuum for 3 days. The loading and encapsulation efficiency (EE) of octreotide acetate, manufacturing yield, and in vitro drug release kinetics in PBStc (10 mM phosphate-buffered saline (PBS) with 1% triethyl citrate and 0.02% sodium azide at pH 7.4) were determined by UPLC. The in vitro release and acylation kinetics of octreotide for the solvent evaporation formulations prepared were similar to SLAR although the initial burst was slightly higher. Key formulation steps identified to maximize microsphere yield and minimize residual solvent and initial burst release included (a) addition of acetic acid to the peptide before preparation and (b) annealing the microspheres under vacuum after drying. Controlled release octreotide formulations prepared and investigated in this study could provide a better understanding of the effect of production variables on release performance and supply information useful for making progress in manufacturing of SLAR generic equivalents.

4.
Altern Ther Health Med ; 27(5): 58-60, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34144528

RESUMO

Objective: The aim of this study was to explore the relationship between psychological distress and disordered eating attitudes. Methods: The study design was cross-sectional study. The 12-item General Health Questionnaire (ghq-12) and Eating Attitude Test-26 (eat-26) were used to measure psychological distress and disordered eating attitudes, respectively. The data were analyzed using spss version 20.0 Software (spss Inc, ii, Chicago, il, usa). Description statistics were used for height, weight, bmi), age, eat-26 scores and ghq-12 scores. Pearson's correlation analysis was performed to explore the relationship between the eat-26 scores and the ghq-12 scores. Results: The overall prevalence of disordered eating attitudes was 4.6%. The mean ghq-12 score in subjects with disordered eating attitude was higher than that of the control group (P < .05) in both the male and female groups. Conclusion: Our study suggested that psychological distress is associated with disordered eating attitudes. Bmi and gender turned out to not be correlated with disordered eating attitude. The findings of this study revealed that university students who have psychological distress also have a tendency toward disordered eating attitudes.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos , Angústia Psicológica , Atitude , Estudos Transversais , Comportamento Alimentar , Transtornos da Alimentação e da Ingestão de Alimentos/epidemiologia , Feminino , Humanos , Masculino , Estudantes , Inquéritos e Questionários , Universidades
5.
Sci Total Environ ; 788: 147856, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34134387

RESUMO

In order to meet the IMO Tier III emissions regulations and reduce environmental pollution, many ocean-going vessels have installed the marine SCR system to reduce NOx emissions. However, the investment cost and operation cost of the marine SCR system, as well as the factors affecting the SCR cost are still the problems that need to be studied. In this paper, MAN S46 diesel engine matched SCR system was taken as the research object, and a cost calculation model of Marine SCR system based on cost analysis method has been proposed. The relationship between SCR system cost and some factors such as unit capacity, unit running time and inlet NOx concentration have been analyzed. The research we have done suggests that operating time, NOx inlet concentration, and emission limits are the three main important factors in the operating cost of an SCR system. Among the various secondary costs of operating costs, the reducing agent cost, fuel increase cost, and indirect annual cost account for 60%, 24%, and 7%, respectively. Moreover, the results suggest that the unit denitration cost of the matched SCR system is highly affected by the power of the diesel engine and annual running time. This study demonstrated clearly the relationship between emission control and economic cost of SCR system for marine diesels and was expected to provide a theoretical basis for sustainable development in marine environmental protection policies.

6.
Ann Palliat Med ; 10(4): 4539-4546, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33966402

RESUMO

BACKGROUND: Obesity, as an epidemic disease, is distributed among all age groups, including children, adolescents, adults, and the elderly. The goal of this study was to investigate the knowledge, attitude, and practice (KAP) concerning obesity among university students. METHODS: In total, 1,317 questionnaires were filled out by 1,317 (466 male and 851 female) randomly selected students aged range from 16 to 24. All participants agreed to provide personal information in this study. A self-designed questionnaire was applied to collect demographic characteristics and assess the KAP of obesity. Gender, height, weight, grade, sleep and income were included in the population questionnaire. Descriptive statistics was used to analyze the respondent rate of KAP among students. RESULTS: In the survey, 64.9% of respondents believed that obesity was a disease. Only a few people cared about their body shape. Most of the participants in the study had practices that were detrimental to their health, including irregular dieting (52.9%), surfing the internet, and playing games (58.5%) in their spare time. CONCLUSIONS: This study identified that lacking knowledge of obesity was common among college students. Most respondents had a positive attitude about preventing obesity by focusing on dieting and exercise. Thus, education related to obesity should be strengthening among university students to translate attitude into practice.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Universidades , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Obesidade/epidemiologia , Obesidade/prevenção & controle , Estudantes , Inquéritos e Questionários , Adulto Jovem
7.
Ann Palliat Med ; 10(4): 4479-4485, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33966395

RESUMO

BACKGROUND: Poor sleep quality is a major health problem worldwide. In universities, poor sleep quality can effect student's ability to study and have a serious impact on their psychological and physical well-being. The aim of this study was to explore the quality of sleep among university students and identify risk factors associated with poor sleep quality. METHODS: A cross-sectional study was conducted and the Pittsburgh sleep quality index scale was used to measure sleep quality. The overall score of the PSQI ranges from 0 to 21, with a score of 4 or less indicating good sleep quality, a score of 5-10 indicating fairly good sleep quality, 11-15 indicating fairly bad sleep quality, and a score of 16-21 indicating poor sleep quality. RESULTS: A total of 1,317 subjects were enrolled in the study. Most subjects were female (64.6%) and rural based (69.2%). Low intensity sports activity more than once per week was reported by 81.9% of subjects and 59.8% reported they participated in high-intensity sports more than once a week. In addition, 72.8% of subjects took a nap more than three times per week. CONCLUSIONS: We found that physical activity and taking a nap may be important factors in improving sleep quality and preventing sleep disorders among university students.


Assuntos
Estudantes , Universidades , Estudos Transversais , Feminino , Humanos , Masculino , Fatores de Risco , Sono
8.
J Am Chem Soc ; 143(14): 5378-5385, 2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33787244

RESUMO

Electrocatalysis from N2 to NH3 has been increasingly studied because it provides an environmentally friendly avenue to take the place of the current Haber-Bosch method. Unfortunately, the conversion of N2 to NH3 is far below the necessary level for implementation at a large scale. Inspired by signal memory in a spiking neural network, we developed rechargeable catalyst technology to activate and remember the optimal catalytic activity using manageable electrical stimulation. Herein, we designed double-faced FeReS3 Janus layers that mimic a multiple-neuron network consisting of resistive switching synapses, enabling a series of intriguing multiphase transitions to activate undiscovered catalytic activity; the activation energy barrier is clearly reduced via an active site conversion between two nonequivalent surfaces. Electrical field-stimulated FeReS3 demonstrates a Faradaic efficiency of 43% and the highest rate of 203 µg h-1 mg-1 toward NH3 synthesis. Moreover, this rechargeable catalyst displays unprecedented catalytic performance that persists for up to 216 h and can be repeatedly activated through a simple charging operation.


Assuntos
Biocatálise , Redes Neurais de Computação , Neurônios/citologia , Neurônios/metabolismo , Nitrogênio , Sinapses/metabolismo
9.
Eur J Pharm Biopharm ; 158: 401-409, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33122118

RESUMO

Bydureon® (Bdn) is a once-weekly injectable long-acting release (LAR) product for adults with type 2 diabetes based on PLGA microspheres encapsulating the glucagon like peptide (GLP-1) analog, exenatide. Despite its widespread use in type 2 diabetes treatment, little information has been published concerning the physical-chemical aspects and exenatide stability in this product. Here, we developed and validated methods to evaluate attributes and performance of Bdn such as particle size/size distribution and residual levels of moisture and organic solvent(s). The reverse engineering of the exenatide LAR was also performed to identify and quantify principal components in the product. Stability-indicating UPLC and LC-MS methods were applied to characterize exenatide degradation (such as oxidation, deamidation and acylation products) during in vitro release evaluation. The 55-µm volume-median Bdn microspheres slowly released the exenatidein vitroover two months with a very low initial burst release to avoid unwanted side effects. Residual organic solvent levels (methylene chloride, ethanol, heptane, and silicon oil) also met the USP criteria. Peptide acylation was the most prominent peptide reaction during both encapsulation and in vitro release, and the acylated peptide steadily increased during release relative to parent exenatide, becoming the most abundant peptide species extracted from the microspheres at later release stages. The presence of peptide impurities during the release period, which are not extractable in the polymer and likely insoluble in water, might be one potential cause for immunogenicity. Further evaluation will be needed to confirm this hypothesis. Release of peptide was minimal over the first 2 weeks before the microspheres steadily released peptide for more than 28 days. The rigorous technical approach discussed in this paper may provide critical information for both companies and the FDA for developing generic exenatide-PLGA formulations and other important PLGA microsphere products.

10.
Artigo em Inglês | MEDLINE | ID: mdl-33081186

RESUMO

Understanding heterogeneous impact and mechanisms between national income and mental health are crucial to develop prevention and intervention strategies. Based on panel data from 2007 to 2017, this study explores the heterogeneous impact of national income on different types of mental health. Then, it analyzes the heterogeneous impact among countries with different income levels. Furthermore, the heterogeneous moderating effects of national income on mental health mechanisms are elaborated and the findings reveal several key conclusions: firstly, national income exerts a heterogeneous impact on different types of mental health. Rising national income is conducive to increase people's happiness and reduce their prevalence of anxiety disorders, but it increases the prevalence of depression disorders. Secondly, national income has a heterogeneous impact on different types of mental health among countries with different income levels. Furthermore, the heterogeneous influence mechanism of national income on mental health is mainly reflected in different types of mental health. Unemployment, social support and freedom can moderate the relationship between national income and depression, while social support, positive affect and negative affect can moderate the relationship between national income and anxiety. Finally, based on the conclusions of quantitative analysis, some important policy recommendations are proposed for policy makers.


Assuntos
Renda , Transtornos Mentais , Saúde Mental , Ansiedade , Transtornos de Ansiedade , Felicidade , Humanos
11.
Mol Pharm ; 17(11): 4141-4151, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32876463

RESUMO

Sandostatin LAR (SLAR) is an injectable long-acting release (LAR) microsphere formulation for octreotide based on a biodegradeable glucose star copolymer of d,l-lactic and glycolic acids (PLGA-glu), which is primarily used for the treatment of patients with acromegaly. There currently is no generic SLAR approved in the United States despite expiration of patent coverage. To understand better this important formulation, SLAR was assessed for its composition and physical-chemical properties. Octreotide release kinetics was monitored under physiological conditions over 56 days together with several bioerosion parameters [mass loss, water uptake, pH of release media, polymer molecular weight (Mw), and confocal microscopy after BODIPY uptake]. A significant increase in the amount of released peptide occurred after day 14. After 1 day of incubation in PBST, octreotide was not extractable completely from SLAR during 2 h of the extraction process, but complete extraction was accomplished after 24 h, which suggested that strong and noncovalent PLGA-octreotide interactions occurred beginning in the initial release phase. Leuprolide is considered as a cationic peptide competitor for octreotide-PLGA interactions and its presence in the release medium resulted in more continuous octreotide release from SLAR, which was linearly correlated with the mass loss from the polymer (i.e., an indication of erosion-controlled release). These data strongly suggest that octreotide forms a salt with acid end groups of linear PLGA chains that are either present as impurities in, and/or produced by the degradation of, the PLGA-Glu. This salt is expected to catalyze octreotide acylation and extend peptide release beyond that driven by erosion control. The characterization studies of physicochemical properties of SLAR described here could be useful for the development and regulatory evaluation of generic octreotide microspheres as well as new polymer formulations, in which the polymer strongly interacts with encapsulated peptides.

12.
Nano Lett ; 20(7): 4960-4967, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32463682

RESUMO

The future of sustainable fertilizers and carbon-free energy carrier demands innovative breakthroughs in the exploitation of efficient electrocatalysts for synthesizing ammonia (NH3) from nitrogen (N2) in mild conditions. Understanding and regulating the reaction intermediates that form on the catalyst surface through careful catalyst design could bypass certain limitations associated with ambiguous adsorbate evolution mechanism. Herein, we propose ternary intermetallic Re2MnS6 ultrathin nanosheets that include orderly hybridized Mn-Re dual-metal sites through strong Hubbard e-e interaction, demonstrating a promising selectivity toward reaction process from N2 to NH3. The ordered inclusion of Mn sites leads to a structural phase transition and appearance of nonbonding semimetal states, in which the rate-limiting activation energy barrier is significantly decreased through a conversion in reaction pathway. As a result, the performance of N2 reduction in Re2MnS6 is increased about 6.6 times compared to the single-metal ReS2.

13.
ACS Appl Mater Interfaces ; 11(42): 38405-38416, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31556594

RESUMO

Intervertebral disc degeneration associated back pain is the most common cause of disability worldwide; however, no safe and effective treatments have been available. Here, we report a new functionalized nanofullerene conjugated with a peptide that binds specifically to a formyl peptide receptor-1 (FPR-1) expressed on activated macrophages. The new nanoparticle (aka FT-C60) was synthesized by conjugating carboxyl-C60 with the primary amine group of the peptide with a fluorescence dye for easy detection. The new nanoparticle was characterized by X-ray photoelectron spectroscopy, mass spectroscopy, and gel electrophoresis. It possessed effective radical (hydroxyl and superoxide anions) scavenging capabilities in electron paramagnetic resonance spectroscopy. In cultured cells, the nanoparticle FT-C60 demonstrated preferential binding to FPR-1 on activated macrophages and significantly attenuated mRNA expressions of proinflammatory factors including interleukin-6, interleukin-1, tumor necrosis factor-alpha, and cyclooxygenase-2. In vivo animal studies exhibited that a single intravenous injection of FT-C60 effectively alleviated pain in an established mouse model of radiculopathy for up to post-operation day (POD) 12. Ex vivo near-infrared fluorescence imaging of the mouse spine confirmed the targeting property of FT-C60 toward the injured disc on POD 14. Quantitative analysis of histological staining on spine sections showed that nanoparticle FT-C60 dramatically reduced inflammation at the local injury site compared to injury only on POD 7. In summary, we developed a novel targeted nanoparticle for treatment of lumbar radiculopathy by systemic delivery. This is a first-of-its-kind study for developing a novel class of targeted and systemic nanoparticle therapeutics to treat degenerative disc diseases.


Assuntos
Fulerenos/química , Degeneração do Disco Intervertebral/tratamento farmacológico , Nanopartículas/química , Receptores de Formil Peptídeo/antagonistas & inibidores , Animais , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Radicais Livres/química , Inflamação/etiologia , Inflamação/prevenção & controle , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolissacarídeos/toxicidade , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Nanopartículas/metabolismo , Nanopartículas/uso terapêutico , Nanopartículas/toxicidade , Imagem Óptica , Manejo da Dor , Células RAW 264.7 , Coluna Vertebral/diagnóstico por imagem
14.
Artigo em Inglês | MEDLINE | ID: mdl-31888025

RESUMO

The 2008 international financial crisis triggered a heated discussion of the relationship between public health and the economic environment. We test the relationship between the credit cycle and happiness using the fixed effects model and explore the transmission channels between them by adding the moderating effect. The results show the following empirical regularities. First, the credit cycle has a negative correlation with happiness. This means that credit growth will reduce the overall happiness score in a country/region. Second, the transmission channels between the credit cycle and happiness are different during credit expansion and recession. Life expectancy and generosity can moderate the relationship between the credit cycle and happiness only during credit expansion. GDP per capita can moderate this relationship only during credit recession. Social support, freedom, and positive affect can moderate this relationship throughout the credit cycle. Third, the total impact of the credit cycle on happiness will become positive by the changes in the moderating effects. In general, we can improve subjective well-being if one of the following five conditions holds: (1) with the adequate support from the family and society, (2) with enough freedom, (3) with social generosity, (4) with a positive and optimistic outlook, and (5) with a high level of GDP per capita.


Assuntos
Financiamento Pessoal , Felicidade , Fatores Socioeconômicos , Atitude , Feminino , Humanos , Expectativa de Vida , Masculino
15.
Front Plant Sci ; 9: 526, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29765383

RESUMO

Tetraploid Thinopyrum elongatum, which has superior abiotic stress tolerance characteristics, and exhibits resistance to stripe rust, powdery mildew, and Fusarium head blight, is a wild relative of wheat and a promising source of novel genes for wheat improvement. Currently, a high-resolution Fluorescence in situ hybridization (FISH) karyotype of tetraploid Th. elongatum is not available. To develop chromosome-specific FISH-based markers, the hexaploid Trititrigia 8801 and two accessions of tetraploid Th. elongatum were characterized by different repetitive sequences probes. We found that all E-genome chromosomes could be unambiguously identified using a combination of pSc119.2, pTa535, pTa71, and pTa713 repeats, and the E-genome chromosomes of the wild accessions and the partial amphiploid failed to exhibit any significant variation in the probe hybridization patterns. To verify the validation of these markers, the chromosome constitution of eight wheat- Th. elongatum hybrid derivatives were analyzed. We revealed that these probes could quickly detect wheat and tetraploid Th. elongatum chromosomes in hybrid lines. K16-712-1-2 was a 1E (1D) chromosome substitution line, K16-681-4 was a 2E disomic chromosome addition line, K16-562-3 was a 3E, 4E (3D, 4D) chromosome substitution line, K15-1033-8-2 contained one 4E, two 5E, and one 4ES⋅1DL Robertsonian translocation chromosome, and four other lines carried monosomic 4E, 5E, 6E, and 7E chromosome, respectively. Furthermore, the E-genome specific molecular markers analysis corresponded perfectly with the FISH results. The developed FISH markers will facilitate rapid identification of tetraploid Th. elongatum chromosomes in wheat improvement programs and allow appropriate alien chromosome transfer.

16.
Mol Cytogenet ; 11: 16, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29441130

RESUMO

Background: Amphidiploids generated by distant hybridization are commonly used as genetic bridge to transfer desirable genes from wild wheat species into cultivated wheat. This method is typically used to enhance the resistance of wheat to biotic or abiotic stresses, and to increase crop yield and quality. Tetraploid Thinopyrum elongatum exhibits strong adaptability, resistance to stripe rust and Fusarium head blight, and tolerance to salt, drought, and cold. Results: In the present study, we produced hybrid derivatives by crossing and backcrossing the Triticum durum-Th. elongatum partial amphidiploid (Trititrigia 8801, 2n = 6× = 42, AABBEE) with wheat cultivars common to the Sichuan Basin. By means of cytogenetic and disease resistance analyses, we identified progeny harboring alien chromosomes and measured their resistance to stripe rust. Hybrid progenies possessed chromosome numbers ranging from 40 to 47 (mean = 42.72), with 40.0% possessing 42 chromosomes. Genomic in situ hybridization revealed that the number of alien chromosomes ranged from 1 to 11. Out of the 50 of analyzed lines, five represented chromosome addition (2n = 44 = 42 W + 2E) and other five were chromosome substitution lines (2n = 42 = 40 W + 2E). Importantly, a single chromosome derived from wheat-Th. elongatum intergenomic Robertsonian translocations chromosome was occurred in 12 lines. Compared with the wheat parental cultivars ('CN16' and 'SM482'), the majority (70%) of the derivative lines were highly resistant to strains of stripe rust pathogen known to be prevalent in China. Conclusion: The findings suggest that these hybrid-derivative lines with stripe rust resistance could potentially be used as germplasm sources for further wheat improvement.

17.
Chem Commun (Camb) ; 54(19): 2425-2428, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29457159

RESUMO

We show increased dynamic nuclear polarization by adding a low dosage of a S = 15/2 Gd based endohedral metallofullerene (EMF) to DNP samples. By adding 60 µM Gd2@C79N, the nuclear polarization of 1H and 13C spins from 40 mM 4-oxo-TEMPO increases by approximately 40% and 50%, respectively, at 5 T and 1.2 K. Electron-electron double resonance (ELDOR) measurements show that the high spin EMF shortens the electron relaxation times and increases electron spectral diffusion leading to the increased DNP enhancement.

18.
ACS Appl Mater Interfaces ; 9(21): 17681-17687, 2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28516768

RESUMO

Antioxidative and anti-inflammatory effects of trimetallic nitride endohedral fullerenes carboxyl-Gd3N@C80, a newly developed magnetic resonance imaging (MRI) contrast agent, were investigated. All hydrochalarone and carboxyl-functionalized fullerenes showed effective radical (hydroxyl and superoxide anion) scavenging, whereas the carboxyl-Gd3N@C80 more efficiently attenuated lipopolysaccharide (LPS) induced oxidative stress in macrophages. Carboxyl-Gd3N@C80 also suppressed LPS-elicited mRNA expression of pro-inflammatory inducible nitric oxide synthase and tumor necrosis factor-alpha, and upregulated antioxidative enzyme axis Nrf2 and heme oxygenase-1, possibly via ERK but not AKT signaling pathways. Therefore, carboxyl-Gd3N@C80 held a great promise in becoming a novel theranostic nanoplatform for simultaneously deliver MRI contrast and therapeutic functions to inflammation-related diseases.


Assuntos
Fulerenos/química , Meios de Contraste , Gadolínio , Inflamação , Estresse Oxidativo , Nanomedicina Teranóstica
19.
Bioconjug Chem ; 28(2): 649-658, 2017 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-28061526

RESUMO

Differential diagnosis of chronic post-traumatic osteomyelitis (CPO) from aseptic inflammation remains challenging, since both pathological processes share similar clinical symptoms. Here we utilized a novel targeted metallofullerene nanoparticle based magnetic resonance imaging (MRI) probe IL-13-TAMRA-Gd3N@C80(OH)30(CH2CH2COOH)20 to detect CPO in mouse tibia via overexpressed IL-13Rα2 receptors. The functionalized metallofullerene was characterized by X-ray photoelectron spectroscopy. Upon lipopolysaccharide (LPS) stimulation, macrophage Raw 264.7 cells showed elevated IL-13Rα2 expression via immunofluorescence staining and increased MRI probe binding via built-in TAMRA fluorescence imaging. Trauma was induced in both tibia of mice and bacteria soaked suture was inserted into the right tibia to initiate infection. During the acute phase (1.5 weeks), luminol-bioluminescence imaging revealed much higher myeloperoxidase activity in the infected tibia compared to the sham. In the chronic phase (4 weeks), X-ray radiography illustrated bone deformation in the infected tibia compared to the sham. With T1 weighted sequences, the probe clearly exhibited hyperintensity in the infection foci at both acute and chronic phases, which was not observed in the sham tibia. Histological analysis revealed severe bone structural destruction and massive inflammatory cell infiltration in the infected tibia. Immunohistochemistry confirmed abundant expression of IL-13Rα2 in the infection site. In summary, we developed a noninvasive imaging approach to detect and differentiate CPO from aseptic inflammation using a new IL-13Rα2 targeted metallofullerene MRI probe. In addition, for the first time, IL-13Rα2 was investigated as a unique biomarker in the context of osteomyelitis. Our data established a foundation for the translational application of this MRI probe in the clinical differentiation of CPO.


Assuntos
Fulerenos/química , Gadolínio/química , Subunidade alfa2 de Receptor de Interleucina-13/análise , Interleucina-13/química , Imageamento por Ressonância Magnética/métodos , Osteomielite/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Sequência de Aminoácidos , Animais , Biomarcadores/química , Doença Crônica , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Nanopartículas/química , Células RAW 264.7 , Receptores de Interleucina-13
20.
Small ; 13(8)2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28026111

RESUMO

The carbonaceous nanomaterials known as metallofullerenes have attracted considerable attention due to their attractive properties. The robust nature of the "Trojan Horse" fullerene cage provides an important structural component, which isolates the metal cluster from the bioenvironment. The large carbon surface area is ideally suited for multiple exo-functionalization approaches to modify the hydrophobic cage for a more hydrophilic bioenvironment. Additionally, peptides and other agents are readily covalently attached to this nanoprobe for targeting applications. The recent progress in developing metallofullerenes for next-generation biomedical applications is described. Of special interest are magnetic resonance imaging (MRI) contrast agents. Several recent studies reported cumulative gadolinium deposition in the brain and bones of individuals using commercial clinical MRI contrast agents. Gadolinium-based metallofullerenes provide 2-3 orders of magnitude improvement in MRI relaxivity and potentially lower clinical levels of toxic Gd3+ ions deposited. Other potential biomedical applications are also reviewed herein.


Assuntos
Tecnologia Biomédica/métodos , Fulerenos/química , Nanopartículas Metálicas/química , Metais/química , Animais , Humanos , Imageamento por Ressonância Magnética , Distribuição Tecidual
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