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1.
J Fluoresc ; 30(6): 1365-1374, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32897496

RESUMO

Two new Zn(II)-based coordination polymers {[Zn3(L1)6(H2O)]∙(H2O)4}n (1, HL1 = 4-(tetrazol-5-yl)phenyl-4,2':6',4″-terpyridine) and [Zn2Cl2(L2)2H2O]n (2, HL2 = 4-([2,2':6',2″'-terpyridin]-4'-yl)benzoic acid) have been successfully prepared using two similar organic ligands with distinct donor groups under similar reaction conditions. The distinct structural features and donor atoms make the two complexes show different water stability, and the complex 1 with good water stability, which can be utilized as the sensor for Fe3+ ion detection in water. The value of Stern-Volmer quenching constant of 1 to the Fe3+ is 5.77 × 104 M- 1, which lies in the top region of the reported CP-based sensors. The mechanism investigation reveals that the energy transfer of resonance from the complex 1 to the Fe3+ ion can account for its fluorescent quenching behavior. The treatment activity of compounds 1 and 2 on the postpartum hemorrhage (PPH) was assessed. First, the cytotoxicity of compounds 1 and 2 on human umbilical vein endothelial cells was assessed with Cell Counting Kit-8 detection kit. Then, to evaluate the prevention of compounds 1 and 2 on the PPH, we conducted the Lowry method and detected the clotting factor IX and anticoagulant factor III contents after the indicated treatment. Finally, the inflammatory response in mice was determined by ELISA method, and the IL-6 and IL-8 levels were determined.


Assuntos
Anticoagulantes/química , Anticoagulantes/farmacologia , Ferro/química , Polímeros/química , Hemorragia Pós-Parto/prevenção & controle , Zinco/química , Ácido Benzoico/química , Estabilidade de Medicamentos , Fibrinogênio/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Ligantes , Hemorragia Pós-Parto/metabolismo , Água/química
2.
J Appl Oral Sci ; 32: e20230439, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38896638

RESUMO

OBJECTIVE: To evaluate the effect of the labiolingual diameter and construction of an endodontically treated (ET) anterior tooth with crown restoration on stress distribution and biomechanical safety under occlusal loading. METHODOLOGY: Three-dimensional finite element models were generated for maxillary central incisors with all-ceramic crown restorations. The labiolingual diameters of the tooth, defined as the horizontal distance between the protrusion of the labial and lingual surfaces, were changed as follows: (D1) 6.85 mm, (D2) 6.35 mm, and (D3) 5.85 mm. The model was constructed as follows: (S0) vital pulp tooth; (S1) ET tooth; (S2) ET tooth with a 2 mm ferrule, restored with a fiber post and composite resin core; (S3) ET tooth without a ferrule, restored with a fiber post and composite resin core. A total of 12 models were developed. In total, two force loads (100 N) were applied to the crown's incisal edge and palatal surface at a 45° oblique angle to the longitudinal axis of the teeth. The Von Mises stress distribution and maximum stress of the models were analyzed. RESULTS: Regardless of the loading location, stress concentration and maximum stress (34.07~66.78MPa) in all models occurred in the labial cervical 1/3 of each root. Both labiolingual diameter and construction influenced the maximum stress of the residual tooth tissue, with the impact of the labiolingual diameter being greater. A reduction in labiolingual diameter led to increased maximum stress throughout the tooth. The ferrule reduced the maximum stress of the core of S2 models (7.15~10.69 MPa), which is lower compared with that of S3 models (19.45~43.67 MPa). CONCLUSION: The labiolingual diameter exerts a greater impact on the biomechanical characteristics of ET anterior teeth with crown restoration, surpassing the influence of the construction. The ferrule can reduce the maximum stress of the core and maintain the uniformity of stress distribution.


Assuntos
Resinas Compostas , Coroas , Análise do Estresse Dentário , Análise de Elementos Finitos , Incisivo , Dente não Vital , Dente não Vital/fisiopatologia , Humanos , Fenômenos Biomecânicos , Incisivo/anatomia & histologia , Incisivo/fisiologia , Resinas Compostas/química , Análise do Estresse Dentário/métodos , Técnica para Retentor Intrarradicular , Reprodutibilidade dos Testes , Estresse Mecânico , Valores de Referência , Força de Mordida , Imageamento Tridimensional/métodos , Planejamento de Prótese Dentária , Teste de Materiais , Coroa do Dente/anatomia & histologia , Coroa do Dente/fisiologia
3.
J. appl. oral sci ; 32: e20230439, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1558238

RESUMO

Abstract Objective To evaluate the effect of the labiolingual diameter and construction of an endodontically treated (ET) anterior tooth with crown restoration on stress distribution and biomechanical safety under occlusal loading. Methodology Three-dimensional finite element models were generated for maxillary central incisors with all-ceramic crown restorations. The labiolingual diameters of the tooth, defined as the horizontal distance between the protrusion of the labial and lingual surfaces, were changed as follows: (D1) 6.85 mm, (D2) 6.35 mm, and (D3) 5.85 mm. The model was constructed as follows: (S0) vital pulp tooth; (S1) ET tooth; (S2) ET tooth with a 2 mm ferrule, restored with a fiber post and composite resin core; (S3) ET tooth without a ferrule, restored with a fiber post and composite resin core. A total of 12 models were developed. In total, two force loads (100 N) were applied to the crown's incisal edge and palatal surface at a 45° oblique angle to the longitudinal axis of the teeth. The Von Mises stress distribution and maximum stress of the models were analyzed. Results Regardless of the loading location, stress concentration and maximum stress (34.07~66.78MPa) in all models occurred in the labial cervical 1/3 of each root. Both labiolingual diameter and construction influenced the maximum stress of the residual tooth tissue, with the impact of the labiolingual diameter being greater. A reduction in labiolingual diameter led to increased maximum stress throughout the tooth. The ferrule reduced the maximum stress of the core of S2 models (7.15~10.69 MPa), which is lower compared with that of S3 models (19.45~43.67 MPa). Conclusion The labiolingual diameter exerts a greater impact on the biomechanical characteristics of ET anterior teeth with crown restoration, surpassing the influence of the construction. The ferrule can reduce the maximum stress of the core and maintain the uniformity of stress distribution.

4.
ACS Appl Mater Interfaces ; 6(7): 4638-49, 2014 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-24624939

RESUMO

Facile, efficient, and robust immobilization of metal nanostructures on porous bioscaffolds is an interesting topic in materials chemistry and heterogeneous catalysis. This study reports a facile in situ method for the synthesis and immobilization of small silver nanoparticles (AgNPs) at room temperature on natural eggshell membrane (ESM), which presents interwoven fibrous structure and can be used as a unique protein-based biotemplate. Procyanidin (Pro), a typical plant polyphenol extracted from grape seeds and skins, was first grafted onto ESM fibers to serve as both reductant and stabilizer during the synthesis process. As a result, the AgNPs were facilely synthesized and robustly immobilized on the ESM fibers without additional chemical reductant or physical treatments. The morphology and microstructure of the as-prepared AgNPs@Pro-ESM composites were characterized by combined microscopy and spectroscopy technologies. The results indicate that small AgNPs with mean diameter of 2.46 nm were successfully prepared on the Pro-ESM biotemplate. The composites exhibited good catalytic activity toward the reduction of 4-nitrophenol (4-NP). More importantly, these composite catalysts can be easily recovered and reused for more than eight cycles because of their high stability.


Assuntos
Biflavonoides/química , Catequina/química , Membrana Celular/química , Nanopartículas Metálicas/química , Óvulo/química , Polímeros/química , Proantocianidinas/química , Prata/química , Animais , Catálise , Galinhas , Nitrofenóis/química , Oxirredução , Tamanho da Partícula , Polímeros/síntese química
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