Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Angew Chem Int Ed Engl ; 61(28): e202204661, 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35445780

RESUMO

Oxidizing CH4 into liquid products with O2 under mild conditions still mainly relies on metal catalysis. We prepared a series of sulfone-modified conjugated organic polymers and found that the catalyst with proper SVI content (0.10) could drive O2 →H2 O2 →⋅OH to oxidize CH4 into CH3 OH and HCOOH directly and efficiently at room temperature under light irradiation. Experimental results showed that after 4 h reaction, decomposition rate and residual amounts of H2 O2 were 81.21 % and 4.83 mmol gcat -1 respectively, and CH4 conversion rate was 22.81 %. Mechanism studies revealed that illumination could induce the homolytic dissociation of S=O bonds on catalyst to produce oxygen and sulfur radicals, where the ⋅O could adsorb and activate CH4 , and the ⋅S could supply electrons for 1 O2 to generate H2 O2 and then for decomposing the H2 O2 into ⋅OH timely to oxidize CH4 . This research provided a novel organic catalysis approach for oxygen activation and utilization.

2.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(4): 582-586, 2018 Jul.
Artigo em Zh | MEDLINE | ID: mdl-30378314

RESUMO

OBJECTIVE: To detect interleukin-36-receptor antagonist gene (IL36RN) in Han patients with generalized pustular psoriasis (GPP) alone in Sichuan region for the purpose of clarification of GPP pathogenesis. METHODS: Genomic DNA of GPP patients, psoriasis vulgaris (PV) patients and normal controls was extracted and subjected to PCR for the amplification of entire encoding and splice sites of IL36RN gene followed by bidirectional sequencing. Differences in frequencies of IL36RN variants between three groups were analyzed. The variant frequency between pediatric-onset GPP (PGPP) and adult-onset GPP (AGPP) was also compared. RESULTS: Three IL36RN variants (c.115+6T>C, c.140A>G, c.227C>T) were found in Han GPP patients from Sichuan. Among them, c.115+6T>C had the highest frequency. Compared with PV patients and normal controls, all the variants frequency had statistical significance (P<0.05). There was no significant difference of variants frequency of IL36RN between PGPP and AGPP group (P>0.05). CONCLUSION: IL36RN may be the most common disease-causing gene in the patients with GPP alone in Han population from Sichuan region.


Assuntos
Interleucinas/genética , Psoríase/genética , Adulto , Criança , China , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Genético
3.
Proc Natl Acad Sci U S A ; 105(44): 16849-54, 2008 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-18974221

RESUMO

Graphene molecules, hexafluorotribenzo[a,g,m]coronene with n-carbon alkyl chains (FTBC-Cn, n = 4, 6, 8, 12) and Janus-type "double-concave" conformation, are used to fabricate self-assembly on highly oriented pyrolytic graphite surface. The structural dependence of the self-assemblies with molecular conformation and alkyl chain is investigated by scanning tunneling microscopy and density functional theory calculation. An interesting reverse face "up-down" way is observed in FTBC-C4 assembly due to the existence of hydrogen bonds. With the increase of the alkyl chain length and consequently stronger van der Waals interaction, the molecules no longer take alternating "up-down" orientation in their self-assembly and organize into various adlayers with lamellar, hexagonal honeycomb, and pseudohoneycomb structures based on the balance between intermolecular and molecule-substrate interactions. The results demonstrate that the featured "double-concave" molecules are available block for designing graphene nanopattern. From the results of scanning tunneling spectroscopy measurement, it is found that the electronic property of the featured graphene molecules is preserved when they are adsorbed on solid surface.


Assuntos
Grafite/química , Compostos Policíclicos/química , Eletroquímica , Microscopia de Tunelamento , Modelos Moleculares , Conformação Molecular , Nanoestruturas/química , Propriedades de Superfície
4.
Orthop Surg ; 11(4): 679-689, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31385411

RESUMO

OBJECTIVE: To determine the safety and effectiveness of a cross-linked sodium hyaluronate (CHA) scaffold in cartilage repair. METHODS: Physicochemical properties of the scaffold were determined. The safety and effectiveness of the scaffold for cartilage repair were evaluated in a minipig model of a full-thickness cartilage defect with microfracture surgery. Postoperative observation and hematological examination were used to evaluate the safety of the CHA scaffold implantation. Pathological examination as well as biomechanical testing, including Young's modulus, stress relaxation time, and creep time, were conducted at 6 and 12 months postsurgery to assess the effectiveness of the scaffold for cartilage repair. Furthermore, type II collagen and glycosaminoglycan content were determined to confirm the influence of the scaffold in the damaged cartilage tissue. RESULTS: The results showed that the routine hematological indexes of the experimental animals were within the normal physiological ranges, which confirmed the safety of CHA scaffold implantation. Based on macroscopic observation, it was evident that repair of the defective cartilage in the animal knee joint began during the 6 months postoperation and was gradually enhanced from the central to the surrounding region. The repair smoothness and color of the 12-month cartilage samples from the operation area were better than those of the 6-month samples, and the results for the CHA scaffold implantation group were better than the control group. Greater cell degeneration and degeneration of the adjacent cartilage was found in the implantation group compared with the control group at both 6 and 12 months postoperation, evaluated by O'Driscoll Articular Cartilage Histology Scoring. Implantation with the CHA scaffold matrix promoted cartilage repair and improved its compression capacity. The type II collagen level in the CHA scaffold implantation group tended to be higher than that in the control group at 6 months (2.33 ± 1.50 vs 1.68 ± 0.56) and 12 months postsurgery (3.37 ± 1.70 vs 2.06 ± 0.63). The GAG content in the cartilage of the control group was significantly lower than that of the experimental group (2.17 ± 0.43 vs 3.64 ± 1.17, P = 0.002 at 6 months and 2.27 ± 0.38 vs 4.12 ± 1.02, P = 0.002 at 12 months). Type II collagen and glycosaminoglycan content also demonstrated that CHA was beneficial for the accumulation of both these vital substances in the cartilage tissue. CONCLUSIONS: The CHA scaffold displayed the ability to promote cartilage repair when applied in microfracture surgery, which makes it a promising material for application in the area of cartilage tissue engineering.


Assuntos
Cartilagem Articular/efeitos dos fármacos , Fêmur/cirurgia , Ácido Hialurônico/farmacologia , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Colágeno Tipo II/metabolismo , Modelos Animais de Doenças , Glicosaminoglicanos/metabolismo , Suínos , Porco Miniatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA