RESUMO
The purpose of this work is to explore the properties of the lignin-derived amine-free photoinitiating systems (PISs) during the curing process. Four novel hydrogen donors (HD1, HD2, HD3, and HD4) derived from lignin α-O-4 structural were designed and synthesized by simple methods, and their low C-H bond dissociation energies on methylene were determined by molecular orbitals theory. Four experimental groups using CQ (camphorquinone)/HD PIs formulated with Bis-GMA/TEGDMA (70 w%/30 w%) were compared to CQ/EDB (ethyl 4-dimethylamino benzoate) system. The photopolymerization profiles and double bond conversion rate was tracked by FTIR experiments; the color bleaching ability of the samples and color aging test assay were performed using color indexes measurements; The cytotoxicity of the samples was also compared to EDB related systems. All of the experimental groups with new HDs were compared to the control group with EDB by statistical analysis. Compared to CQ/EDB system, new lignin-derived hydrogen donors combined with CQ showed comparable or even better performances in polymerization initiation to form resin samples, under a blue dental LED in air. Excellent color bleaching property was observed with the new HDs. Aging tests and cytotoxicity examination of the resin were performed, indicating the new lignin compounds to be efficient hydrogen donors for amine-free CQ-based photo-initiating system. Novel lignin α-O-4 derived hydrogen donors are promising for further usage in light-curing materials.
Assuntos
Lignina , Polimerização , Lignina/química , Hidrogênio/química , Terpenos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Resinas Sintéticas/química , Materiais Dentários/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Cânfora/análogos & derivadosRESUMO
IMPORTANCE: Riemerella anatipestifer (R. anatipestifer) is one of the most important veterinary pathogens with at least 21 serotypes. However, the exact polysaccharide(s) that determine R. anatipestifer serotype is still unknown. This study has provided a preliminary exploration of the relationship between capsular polysaccharides and serotyping in R. anatipestifer and suggests possible directions for further investigation of the genetic basis of serotypes in this bacterium.
Assuntos
Doenças das Aves Domésticas , Riemerella , Animais , Sorotipagem , Patos/microbiologia , Riemerella/genética , Polissacarídeos , Doenças das Aves Domésticas/microbiologiaRESUMO
Recent developments in digital technology and materials have improved the accuracy and efficiency of tracking and recording mandibular motion, with various methods being described. The present article describes a digital workflow with complete and accurate 3-dimensional spatial trajectories of mandibular motion to direct the design of lingual restorations. The workflow allowed the lingual curvature of the restoration to conform with the distinctive trajectory of mandibular protrusion.
RESUMO
OBJECTIVES: The aim of this study is to develop amine free photo-initiating system (PIs) for the photopolymerization of dental methacrylate resins, using seven new hydrogen donors HDA-HDG derived from ß-O-4 lignin model. METHODS: Seven experimental CQ/HD PIs were formulated with Bis-GMA/TEGDMA (70 w%/30 w%). CQ/EDB system was chosen as the comparison group. FTIR-ATR was used to monitor the polymerization kinetics and double bond conversion. Bleaching property and color stability were evaluated using a spectrophotometer. Molecular orbitals calculations were used to demonstrate C-H bond dissociation energies of the novel HDs. Depth of cure of the HD based systems were compared to the EDB based one. Cytotoxicity was also studied by CCK8 assay using tissue of mouse fibroblasts (L929 cells). RESULTS: Compared to CQ/EDB system, the new CQ/HD systems show comparable or better photopolymerization performances (1 mm-thick samples). Comparable or even better bleaching properties were also obtained with the new amine-free systems. Comparing to EDB, all HDs exhibited significantly lower C-H bond dissociation energies by molecular orbitals calculations. Groups with new HD showed higher depth of cure. OD and RGR values were similar to that of the CQ/EDB group, ensuring the feasibility of the new HDs in dental materials. CLINICAL SIGNIFICANCE: The new CQ/HD PI systems could be potentially useful in dental materials, presenting improvements in restorations' esthetic and biocompatibility.
Assuntos
Resinas Compostas , Lignina , Animais , Camundongos , Resinas Compostas/química , Estética Dentária , Bis-Fenol A-Glicidil Metacrilato/química , Metacrilatos/química , Ácidos Polimetacrílicos/química , Polietilenoglicóis/química , Aminas/química , Teste de Materiais , Polimerização , Materiais Dentários/químicaRESUMO
Autism spectrum disorder (ASD) is a congenital, lifelong neurodevelopmental disorder whose main symptom is impaired social communication and interaction. However, no drug can treat social deficits in patients with ASD, and treatments to alleviate social behavioral deficits are sorely needed. Here, we examined the effect of oral supplementation of maca (Lepidium meyenii) on social deficits of in utero-exposed valproic acid (VPA) mice, widely used as an ASD model. Although maca is widely consumed as a fertility enhancer and aphrodisiac, it possesses multiple beneficial activities. Additionally, it benefits learning and memory in experimental animal models. Therefore, the effect of maca supplementation on the social behavioral deficit of VPA mice was assessed using a social interaction test, a three-stage open field test, and a five-trial social memory test. The oral supplementation of maca attenuated social interaction behavior deficit and social memory impairment. The number of c-Fos-positive cells and the percentage of c-Fos-positive oxytocin neurons increased in supraoptic and paraventricular neurons of maca-treated VPA mice. These results reveal for the first time that maca is beneficial to social memory and that it restores social recognition impairments by augmenting the oxytocinergic neuronal pathways, which play an essential role in diverse social behaviors.
RESUMO
Investigating the neurocircuit and synaptic sites of action of oxytocin (OT) in the brain is critical to the role of OT in social memory and behavior. To the same degree, it is important to understand how OT is transported to the brain from the peripheral circulation. To date, of these, many studies provide evidence that CD38, CD157, and receptor for advanced glycation end-products (RAGE) act as regulators of OT concentrations in the brain and blood. It has been shown that RAGE facilitates the uptake of OT in mother's milk from the digestive tract to the cell surface of intestinal epithelial cells to the body fluid and subsequently into circulation in male mice. RAGE has been shown to recruit circulatory OT into the brain from blood at the endothelial cell surface of neurovascular units. Therefore, it can be said that extracellular OT concentrations in the brain (hypothalamus) could be determined by the transport of OT by RAGE from the circulation and release of OT from oxytocinergic neurons by CD38 and CD157 in mice. In addition, it has recently been found that gavage application of a precursor of nicotinamide adenine dinucleotide, nicotinamide riboside, for 12 days can increase brain OT in mice. Here, we review the evaluation of the new concept that RAGE is involved in the regulation of OT dynamics at the interface between the brain, blood, and intestine in the living body, mainly by summarizing our recent results due to the limited number of publications on related topics. And we also review other possible routes of OT recruitment to the brain.
RESUMO
This study investigated the correlation between surfactant protein-A (SP-A) polymorphism and the susceptibility of chronic obstructive pulmonary disease (COPD) in Xinjiang Uighurs. Genomic DNA was extracted from peripheral blood of 194 COPD smokers and 201 healthy smokers of Uighur who were hospitalized in or paid a visit to one of the four Xinjiang-based hospitals involved in the study, from March 2009 to December 2010. Single nucleotide polymorphisms (SNPs) were studied at aa62 (CCA/CCG rs1136451) and aa219 (CGG/TGG, rs4253527) in SP-A. Genotypes were determined by using the TaqMan polymerase chain reaction (PCR). Our results showed that genotype frequencies were different between the COPD and normal smokers in aa62 (x (2)=6.852, P=0.033). There were also significant differences in allele genotype frequencies between the COPD and the control and allele G might decrease the risk COPD (x (2)=6.545, P=0.011; OR=0.663; 95% CI: 0.484-0.909). The result suggested that polymorphism of aa62 (CCA/CCG, rs1136451) of SP-A may be associated with the susceptibility to COPD in Xinjiang Uighurs.
Assuntos
Predisposição Genética para Doença/etnologia , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único/genética , Doença Pulmonar Obstrutiva Crônica/etnologia , Doença Pulmonar Obstrutiva Crônica/genética , Proteína A Associada a Surfactante Pulmonar/genética , China/epidemiologia , Marcadores Genéticos/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de RiscoRESUMO
This study investigated the correlation between surfactant protein-A (SP-A) polymorphism and the susceptibility of chronic obstructive pulmonary disease (COPD) in Xinjiang Uighurs.Genomic DNA was extracted from peripheral blood of 194 COPD smokers and 201 healthy smokers of Uighur who were hospitalized in or paid a visit to one of the four Xinjiang-based hospitals involved in the study,from March 2009 to December 2010.Single nucleotide polymorphisms (SNPs) were studied at aa62 (CCA/CCG rs 1136451) and aa219 (CGG/rGG,rs4253527) in SP-A.Genotypes were determined by using the TaqMan polymerase chain reaction (PCR).Our results showed that genotype frequencies were different between the COPD and normal smokers in aa62 (x2=6.852,P=0.033).There were also significant differences in allele genotype frequencies between the COPD and the control and allele G might decrease the risk COPD (x2=6.545,P=0.011; OR=0.663; 95% CI:0.484-0.909).The result suggested that polymorphism of aa62 (CCA/CCG,rs1136451) of SP-A may be associated with the susceptibility to COPD in Xinjiang Uighurs.