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1.
J Peripher Nerv Syst ; 28(4): 629-641, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37749855

RESUMO

BACKGROUND AND AIMS: Neuronal intranuclear inclusion disease (NIID) is a rare progressive neurodegenerative disorder mainly caused by abnormally expanded GGC repeats within the NOTCH2NLC gene. Most patients with NIID show polyneuropathy. Here, we aim to investigate diagnostic electrophysiological markers of NIID. METHODS: In this retrospective dual-center study, we reviewed 96 patients with NOTCH2NLC-related NIID, 94 patients with genetically confirmed Charcot-Marie-Tooth (CMT) disease, and 62 control participants without history of peripheral neuropathy, who underwent nerve conduction studies between 2018 and 2022. RESULTS: Peripheral nerve symptoms were presented by 53.1% of patients with NIID, whereas 97.9% of them showed peripheral neuropathy according to electrophysiological examinations. Patients with NIID were characterized by slight demyelinating sensorimotor polyneuropathy; some patients also showed mild axonal lesions. Motor nerve conduction velocity (MCV) of the median nerve usually exceeded 35 m/s, and were found to be negatively correlated with the GGC repeat sizes. Regarding the electrophysiological differences between muscle weakness type (n = 27) and non-muscle weakness type (n = 69) of NIID, nerve conduction abnormalities were more severe in the muscle weakness type involving both demyelination and axonal impairment. Notably, specific DWI subcortical lace sign was presented in only 33.3% of muscle weakness type, thus it was difficult to differentiate them from CMT. Combining age of onset, distal motor latency, and compound muscle action potential of the median nerve showed the optimal diagnostic performance to distinguish NIID from major CMT (AUC = 0.989, sensitivity = 92.6%, specificity = 97.4%). INTERPRETATION: Peripheral polyneuropathy is common in NIID. Our study suggest that nerve conduction study is useful to discriminate NIID.


Assuntos
Doença de Charcot-Marie-Tooth , Doenças Neurodegenerativas , Humanos , Estudos de Condução Nervosa , Estudos Retrospectivos , Doenças Neurodegenerativas/diagnóstico , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/patologia , Debilidade Muscular
2.
J Fluoresc ; 30(3): 621-627, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32300978

RESUMO

A luminescent coordination polymer based on Tb(III) has been synthesized with the tripodal carboxylic acid ligand containing N,O codonors (H2PBA = 5-[4-pyridin-3-yl-benzoylamino]-isophthalic acid) as ligand under solvothermal conditions. The chemical formula of this polymer is {[Tb2(PBA)3(H2O)3]·DMF·3H2O}n (1). Complex 1 has good sensitivity and selectivity to picric acid (PA). At 0-30 µmol/L, 1's quenching constant is 4.5 × 104 L/mol. In the biological function study, the motor function of spinal cord-injured animals after different treatments was evaluated using the blood-brain barrier (BBB) method. The trka expression level on the neural stem cells after treatment was measured to reveal the underlying mechanism.


Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Modelos Animais de Doenças , Picratos/análise , Receptor trkA/metabolismo , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Complexos de Coordenação/síntese química , Luminescência , Células-Tronco Neurais/metabolismo , Polímeros/química , Polímeros/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor trkA/genética , Traumatismos da Medula Espinal/metabolismo , Térbio/química , Térbio/farmacologia , Regulação para Cima/efeitos dos fármacos
3.
Opt Lett ; 39(8): 2378-81, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24978997

RESUMO

We demonstrated amplified spontaneous emission by embedding dye molecules within a dielectric layer of a metal-dielectric-metal subwavelength structure. It was reinforced when a strong coupling occurred between the Fabry-Perot mode supported by the dielectric layer and the surface plasmon polariton mode supported by the adjacent metallic grating. Here, we adjust the two mode interaction via tuning the depth of the metallic grating grooves. The stronger the interaction, the smaller the full width at half-maximum of the emission spectra and the lower the threshold of the amplified spontaneous emission.


Assuntos
Ressonância de Plasmônio de Superfície/instrumentação , Corantes Fluorescentes , Microtecnologia , Fenômenos Ópticos , Polimetil Metacrilato , Prata , Espectrometria de Fluorescência
4.
Int J Biol Macromol ; 266(Pt 2): 131000, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38521333

RESUMO

In recent years, the development of probiotic film by incorporating probiotics into edible polymers has attracted significant research attention in the field of active packaging. However, the influence of the external environment substantially reduces the vitality of probiotics, limiting their application. Therefore, to improve the probiotic activity, this study devised a novel nanofiber film incorporating chia mucilage protection solution (CPS), gum arabic (GA), pullulan (PUL), and Lactobacillus bulgaricus (LB). SEM images indicated the successful preparation of the nanofiber film incorporating LB. CPS incorporation significantly improved the survival ability of LB, with a live cell count reaching 7.62 log CFU/g after 28 days of storage at 4 °C - an increase of 1 log CFU/g compared to the fiber film without CPS. The results showed that the fiber film containing LB inhibited Escherichia coli and Staphylococcus aureus. Finally, the novel probiotic nanofiber film was applied to beef. The results showed that the shelf life of the beef during the experiments was extended for 2 days at 4 °C. Therefore, the novel probiotic film containing LB was suitable for meat preservation.


Assuntos
Antibacterianos , Glucanos , Goma Arábica , Nanofibras , Nanofibras/química , Glucanos/química , Glucanos/farmacologia , Goma Arábica/química , Antibacterianos/farmacologia , Antibacterianos/química , Salvia/química , Lactobacillus delbrueckii , Probióticos/química , Animais , Conservação de Alimentos/métodos , Carne Vermelha/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Mucilagem Vegetal/química , Escherichia coli/efeitos dos fármacos , Bovinos , Embalagem de Alimentos/métodos
5.
Food Chem ; 411: 135497, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36696720

RESUMO

In this study, a bilayer film (BIF) was fabricated to improve the stability of an anthocyanin-based freshness indicator film. The sensor layer consists of gellan gum (GG) and mulberry anthocyanin (MAE) for freshness indication. The oxygen barrier layer was constructed from chitosan (CS), polyvinyl alcohol (PVA), sodium alginate (SA), and pullulan (Pu) to the protection of MAE from oxidation. The highest antioxidant activity of BIF was 91.28 %. BIF was used to monitor the Chinese mitten crab freshness. The total volatile basic nitrogen (TVB-N) level was increased to 31.23 mg/100 g on day 8, and the color of the indicator presented a visible change from pink to dark green. The acquired results revealed a good correlation between TVB-N, pH, and color change of the indicator. The research indicated that the BIF was applied for freshness monitoring of Chinese mitten crab and displayed significant color changes that would be effective in commercial environments.


Assuntos
Antocianinas , Morus , Embalagem de Alimentos/métodos , Alimentos Marinhos , Álcool de Polivinil , Concentração de Íons de Hidrogênio
6.
Microb Biotechnol ; 15(5): 1324-1338, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34592061

RESUMO

Plastics materials used for food packaging are recalcitrant, leading to a growing global environmental problem, which arouses the attention of environmental protection departments in many countries. Therefore, to meet the increasing demand for sustainable and environment-friendly consumer products, it is necessary for the food industry to develop natural antibacterial materials for food preservation. This review summarizes the common biodegradable natural antimicrobial agents and their applications in food preservation; as well as an overview of five commonly used biodegradable protein-based polymers, such as zein, soy protein isolate, gelatin and whey protein, with special emphasis on the advantages of protein-based biopolymers and their applications in food packaging industry.


Assuntos
Embalagem de Alimentos , Conservação de Alimentos , Antibacterianos/farmacologia , Biopolímeros , Polímeros
7.
Shanghai Kou Qiang Yi Xue ; 31(3): 313-317, 2022 Jun.
Artigo em Zh | MEDLINE | ID: mdl-36204964

RESUMO

PURPOSE: To analyze the clinical effect of digital impression combined with all-ceramic denture restoration on patients with dental defects. METHODS: A study was conducted on 120 patients with dental defects admitted to Dongfeng Stomatological Hospital from June 2018 to June 2020. The two groups of patients were randomly divided into digital imprinting modules and silicone rubber imprinting modules using a random number table method. There were 60 cases in each group. The silicone rubber imprint module used traditional silicone impression combined with all-ceramic denture restoration, while the digital imprint module used digital impression combined with all-ceramic denture restoration.The clinical efficacy of the two groups was observed. Gingival index (GI), periodontal index (PI) before dental restoration, during dental restoration and 6 monthes after dental restoration were compared. The adjacent surface contact conditions, occlusion and adverse reactions of the two groups were compared. SPSS 22.0 software package was used for statistical analysis. RESULTS: The two groups of patients selected grade A and grade B for the evaluation of the restoration when the restoration was completed. The number of patients who chose grade A for the digital imprint module was more than that of the silicone rubber imprint module,but there was no significant difference(P>0.05). Six months after the tooth was worn, GI and PI indexes of the two groups of patients increased. GI and PI indexes of the silicone rubber stamping module were significantly higher than those of the digital stamping module(P<0.05). When dental restoration was completed and 6 months after the tooth was replaced, the pass rate of contact between the adjacent surfaces of the imprinting module patients was significantly higher than that of the silicone rubber imprinting module(P<0.05). When dental restoration was completed, the occlusion of the digital imprinting module patients was significantly better than that of the silicone rubber imprinting module(P<0.05). Six months after wearing the denture, there was no significant difference in occlusion between the two groups of patients(P>0.05). When dental models of the two groups of patients were taken, the incidence of adverse reactions in patients with digital imprints was significantly lower than that of silicone rubber imprints(P<0.05). CONCLUSIONS: The use of digital impressions combined with all-ceramic restorations to repair patients with dental defects can effectively improve the treatment effect, improve prognostic GI and PI indexes of the patients, increase the pass rate of the adjacent surface contact and occlusion of the tooth, and reduce the process of dental restoration. The incidence of adverse reactions are minimal, with good prognostic effects. It is worthy of clinical application.


Assuntos
Coroas , Porcelana Dentária , Cerâmica , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Planejamento de Prótese Dentária/métodos , Dentaduras , Humanos , Elastômeros de Silicone
8.
Ying Yong Sheng Tai Xue Bao ; 30(2): 511-517, 2019 Feb 20.
Artigo em Zh | MEDLINE | ID: mdl-30915803

RESUMO

To explore the effects of forest types and slope positions on the content of soil organic carbon (SOC) and total nitrogen (TN) in the lower hilly area of Taihang Mountains, we examined the distribution pattern of SOC and TN contents in Quercus variabilis plantation (Qo), and Platycladus orientalis plantation (Po), and abandoned land (Al). The results showed that in the same forest type or slope position, the contents of SOC and TN gradually decreased with increasing soil depth. Under different slope conditions, the contents of SOC and TN showed the tendency of upper-slope (U) > middle-slope (M) > lower-slope (L) in the planted forests (Qo and Po), but showed the tendency of L>U>M in Al. Under different forest types, the contents of SOC and TN in the U and M showed the trend of Qo>Po>Al. At the LS, the contents of SOC and TN of Al were the highest. The C/N ratio followed an order of Qo>Po> Al at U and M, while Qo>Al> Po at L. Within the same forest type, C/N of different slopes was different, but not significant. Our results suggested that the adaptability of the Qo plantation is the best in the lower hilly area of Taihang Mountains.


Assuntos
Florestas , Carbono , Queixo , Nitrogênio , Solo
9.
ChemMedChem ; 12(18): 1504-1511, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28776965

RESUMO

Small-molecular-target-based photodynamic therapy-a promising targeted anticancer strategy-was developed by conjugating zinc(II) phthalocyanine with a small-molecular-target-based anticancer drug. To prevent self-aggregation and avoid problems of phthalocyanine isomerization, two silicon phthalocyanines di-substituted axially with erlotinib have been synthesized and fully characterized. These conjugates are present in monomeric form in various solvents as well as culture media. Cell-based experiments showed that these conjugates localize in lysosomes and mitochondria, while maintaining high photodynamic activities (IC50 values as low as 8 nm under a light dose of 1.5 J cm-2 ). With erlotinib as the targeting moiety, two conjugates were found to exhibit high specificity for EGFR-overexpressing cancer cells. Various poly(ethylene glycol) (PEG) linker lengths were shown to have an effect on the photophysical/photochemical properties and on in vitro phototoxicity.


Assuntos
Antineoplásicos/química , Cloridrato de Erlotinib/química , Indóis/química , Compostos de Organossilício/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Receptores ErbB/metabolismo , Células Hep G2 , Humanos , Luz , Neoplasias Hepáticas/tratamento farmacológico , Microscopia Confocal , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Polietilenoglicóis/química , Espécies Reativas de Oxigênio/metabolismo , Zinco/química
10.
Folia Microbiol (Praha) ; 60(1): 69-80, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25147055

RESUMO

As one of the most clinically relevant human habitats, the human mouth is colonized by a set of microorganisms, including bacteria, archaea, fungi, and viruses. Increasing evidence has supported that these microbiota contribute to the two commonest oral diseases of man (dental caries and periodontal diseases), presenting significant risk factors to human health conditions, such as tumor, diabetes mellitus, cardiovascular diseases, bacteremia, preterm birth, and low birth weight in infants. It is widely accepted that oral microorganisms cause diseases mainly by a synergistic or cooperative way, and the interspecies interactions within the oral community play a crucial role in determining whether oral microbiota elicit diseases or not. Since a comprehensive understanding of the complex interspecies interactions within a community needs the knowledge of its endogenous residents, a plenty of research have been carried out to explore the oral microbial diversity. In this review, we focus on the recent progress in this field, including the oral microbiome composition and its association with human diseases.


Assuntos
Bactérias/isolamento & purificação , Biodiversidade , Microbiota , Doenças da Boca/microbiologia , Boca/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Humanos
11.
Biomed Res Int ; 2015: 909870, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25710035

RESUMO

In order to investigate the potential of short antimicrobial peptides (AMPs) as alternative antibacterial agents during the treatment of peri-implantitis, the cytotoxic activity of three short AMPs, that is, Pac-525, KSL-W, and KSL, was determined using the MTT assay. The antimicrobial activity of these AMPs, ranging in concentration from 0.0039 mg/mL to 0.5 mg/mL, against the predominant planktonic pathogens, including Streptococcus sanguis, Fusobacterium nucleatum, and Porphyromonas gingivalis, involved in peri-implantitis was investigated. Furthermore, 2-day-old P. gingivalis biofilms cultured on titanium surfaces were treated with Pac-525 and subsequently observed and analysed using confocal laser scanning microscopy (CLSM). The average cell proliferation curve indicated that there was no cytotoxicity due to the three short AMPs. The minimum inhibitory concentration and minimum bactericidal concentration values of Pac-525 were 0.0625 mg/mL and 0.125 mg/mL, respectively, for P. gingivalis and 0.0078 mg/mL and 0.0156 mg/mL, respectively, for F. nucleatum. Using CLSM, we confirmed that compared to 0.1% chlorhexidine, 0.5 mg/mL of Pac-525 caused a significant decrease in biofilm thickness and a decline in the percentage of live bacteria. These data indicate that Pac-525 has unique properties that might make it suitable for the inhibition the growth of pathogenic bacteria around dental implants.


Assuntos
Antibacterianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Biofilmes/crescimento & desenvolvimento , Implantes Dentários/microbiologia , Porphyromonas gingivalis/fisiologia , Titânio , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Biofilmes/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Materiais Dentários , Relação Dose-Resposta a Droga , Porphyromonas gingivalis/efeitos dos fármacos , Resultado do Tratamento
12.
Colloids Surf B Biointerfaces ; 136: 752-60, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26519937

RESUMO

As an attractive technique for the improvement of biomaterials, Plasma immersion ion implantation (PIII) has been applied to modifying the titanium material for dental implant application. The present study investigated the cytocompatibility and early osseointegration of fluoride-ion-implanted titanium (F-Ti) surface and implants, both characterizing in their composition of titanium oxide and titanium fluoride. The cytocompatibility of F-Ti was evaluated in vitro by using scanning electron microscope, Cell Counting Kit-8 assay, alkaline phosphatase activity assay, and quantitative real-time polymerase chain reaction. The results showed that the F-Ti weakened the effects that Porphyromonas gingivalis exerted on the MG-63 cells in terms of morphology, proliferation, differentiation, and genetic expression when MG-63 cells and Porphyromonas gingivalis were co-cultured on the surface of F-Ti. Meanwhile, the osteogenic activity of F-Ti implants was assessed in vivo via evaluating the histological morphology and estimating histomorphometric parameters. The analysis of toluidine blue staining indicated that the new bone was more mature in subjects with F-Ti group, which exhibited the Haversian system, and the mean bone-implant contact value of F-Ti group was slightly higher than that of cp-Ti group (p>0.05). Fluorescence bands were wider and brighter in the F-Ti group, and the intensity of fluorochromes deposited at the sites of mineralized bone formation was significantly higher for F-Ti surfaces than for cp-Ti surfaces, within the 2nd, 3rd and 4th weeks (p<0.05). An indication is that the fluoride modified titanium can promote cytocompatibility and early osseointegration, thus providing a promising alternative for clinical use.


Assuntos
Materiais Biocompatíveis , Implantes Dentários , Fluoretos/química , Osseointegração , Titânio/química , Linhagem Celular , Humanos , Propriedades de Superfície
13.
J Agric Food Chem ; 62(28): 6726-35, 2014 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-24745755

RESUMO

This study was conducted to understand how carotenoids exerted antioxidant activity after encapsulation in a liposome delivery system, for food application. Three assays were selected to achieve a wide range of technical principles, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, ferric reducing antioxidant powder (FRAP), and lipid peroxidation inhibition capacity (LPIC) during liposome preparation, auto-oxidation, or when induced by ferric iron/ascorbate. The antioxidant activity of carotenoids was measured either after they were mixed with preformed liposomes or after their incorporation into the liposomal system. Whatever the antioxidant model was, carotenoids displayed different antioxidant activities in suspension and in liposomes. The encapsulation could enhance the DPPH scavenging and FRAP activities of carotenoids. The strongest antioxidant activity was observed with lutein, followed by ß-carotene, lycopene, and canthaxanthin. Furthermore, lipid peroxidation assay revealed a mutually protective relationship: the incorporation of either lutein or ß-carotene not only exerts strong LPIC, but also protects them against pro-oxidation elements; however, the LPIC of lycopene and canthaxanthin on liposomes was weak or a pro-oxidation effect even appeared, concomitantly leading to the considerable depletion of these encapsulated carotenoids. The antioxidant activity of carotenoids after liposome encapsulation was not only related to their chemical reactivity, but also to their incorporation efficiencies into liposomal membrane and modulating effects on the membrane properties.


Assuntos
Antioxidantes/farmacologia , Carotenoides/administração & dosagem , Carotenoides/farmacologia , Compostos de Bifenilo/química , Cápsulas , Sistemas de Liberação de Medicamentos , Compostos Férricos/química , Peroxidação de Lipídeos/efeitos dos fármacos , Lipossomos , Luteína/farmacologia , Licopeno , Oxirredução , Picratos/química , beta Caroteno/farmacologia
14.
Food Funct ; 5(6): 1232-40, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24714683

RESUMO

This study compared the loading ability of various carotenoids into liposomal membrane, lipid peroxidation inhibition capacity, storage stability and in vitro release behavior in simulated gastrointestinal (GI) media. It was found that carotenoids exhibited various incorporating abilities into liposomes ranging from the strongest to the weakest: lutein > ß-carotene > lycopene > canthaxanthin. A similar trend was also observed in their antioxidant activities against lipid peroxidation during preparation. Storage measurements demonstrated that a liposomal membrane can strongly retain ß-carotene and lutein, whereas this effect was not pronounced for lycopene and canthaxanthin. In vitro release experiments showed that lutein and ß-carotene were hardly released in a simulated gastric fluid, while displaying a slow and sustained release in a simulated intestinal fluid. By contrast, lycopene and canthaxanthin underwent fast and considerable release in GI media. Dynamic light scattering indicated that carotenoid incorporation strongly affected the particle stability and dispersion during preparation and GI incubation. The differences in molecular release may be attributed to the different modulating effects of carotenoids. Our results may guide the potential application of liposomes as carriers for the controlled delivery of carotenoids in nutraceutical and functional foods.


Assuntos
Cantaxantina/farmacologia , Carotenoides/farmacologia , Portadores de Fármacos/química , Lipossomos/química , Luteína/farmacologia , beta Caroteno/farmacologia , Antioxidantes/farmacologia , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Peroxidação de Lipídeos , Licopeno , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
15.
J Agric Food Chem ; 61(34): 8175-84, 2013 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-23906192

RESUMO

Lutein was loaded into liposomes, and their stability against environmental stress was investigated. Subsequently, these findings were correlated with the interactions between lutein and lipid bilayer. Results showed that the liposomes with loaded lutein at concentrations of 1 and 2% remained stable during preparation, heating, storage, and surfactant dissolution. However, with further increase in the loading concentration to 5 and 10%, the stabilization role of lutein on membrane was not pronounced or even opposite. Membrane fluidity demonstrated that at 1 and 2%, lutein displayed less fluidizing properties both in the headgroup region and in the hydrophobic core of the liposome, whereas this effect was not significant at 5 and 10%. Raman spectra demonstrated that lutein incorporation greatly affected the lateral packing order between acyl chains and longitudinal packing order of lipid acyl chains. These results may guide the potential application of liposomes as carriers for lutein in nutraceuticals and functional foods.


Assuntos
Portadores de Fármacos/química , Lipossomos/química , Luteína/química , Animais , Embrião de Galinha , Composição de Medicamentos , Estabilidade de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Bicamadas Lipídicas/química , Fosfolipídeos/química
16.
J Agric Food Chem ; 61(28): 6901-10, 2013 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-23772808

RESUMO

This study was devoted to a further understanding of the dependence of liposomal membrane properties on chitosan conformation and proved the dual effects of chitosan. The concentration dependence of chitosan conformation in aqueous solution was illustrated by surface tension and fluorescence probe techniques. Fluorescence and Raman spectra were subsequently employed to investigate the dynamic and structural changes of the liposomal membrane resulting from chitosan decoration. Results showed that the unfolded and crimped chains of chitosan flatly adsorbed onto the membrane surface via electrostatic attraction and favored liposome stability. Furthermore, the adsorption of crimped chains seemed stronger due to the embedding of their hydrophobic moieties. However, the presence of chitosan coils induced the increase in membrane fluidity, the intrachain disorder in lipid molecules, and the gauche conformation change of choline group. Dynamic light scattering and lipid oxidation measurements demonstrated that this perturbation was correlated with the permeation of coils into the lipid bilayer.


Assuntos
Quitosana/química , Lipossomos/química , Adsorção , Configuração de Carboidratos , Fenômenos Químicos , Quitosana/farmacologia , Luz , Bicamadas Lipídicas/química , Peroxidação de Lipídeos , Fluidez de Membrana , Espalhamento de Radiação , Soluções , Espectrometria de Fluorescência , Análise Espectral Raman , Eletricidade Estática , Água
17.
Anal Chim Acta ; 658(2): 180-6, 2010 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-20103092

RESUMO

A novel method of first derivative synchronous fluorescence was developed for the rapid simultaneous analysis of trace 1-hydroxypyrene (1-OHP), 1-naphthol (1-NAP), 2-naphthol (2-NAP), 9-hydroxyphenanthrene (9-OHPe) and 2-hydroxyfluorene (2-OHFlu) in human urine. Only one single scan was needed for quantitative determination of five compounds simultaneously when Deltalambda=10 nm was chosen. In the optimal experimental conditions, there was a linear relationship between the fluorescence intensity and the concentration of 1-OHP, 1-NAP, 2-NAP, 9-OHPe and 2-OHFlu in the range of 1.75 x 10(-9) to 4.50 x 10(-6) mol L(-1), 3.64 x 10(-8) to 2.20 x 10(-4) mol L(-1), 8.18 x 10(-9) to 1.20 x 10(-4) mol L(-1), 3.26 x 10(-9) to 8.50 x 10(-5) mol L(-1) and 4.88 x 10(-9) to 5.50 x 10(-6) mol L(-1), respectively. The limits of detection (LOD) were found to be 5.25 x 10(-10) mol L(-1) for 1-OHP, 1.10 x 10(-8) mol L(-1) for 1-NAP, 2.46 x 10(-9) mol L(-1) for 2-NAP, 9.77 x 10(-10) mol L(-1) for 9-OHPe and 1.46 x 10(-9) mol L(-1) for 2-OHFlu. The proposed method is reliable, selective and sensitive, and has been used successfully in the determination of traces of 1-OHP, 1-NAP, 2-NAP, 9-OHPe and 2-OHFlu in human urine samples, whose results were in good agreement with those gained by the HPLC method.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/urina , Polissorbatos/química , Espectrometria de Fluorescência/métodos , Tensoativos/química , Fluorenos/urina , Humanos , Concentração de Íons de Hidrogênio , Naftóis/urina , Fenantrenos/urina , Hidrocarbonetos Policíclicos Aromáticos/química , Pirenos/análise
18.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 38(6): 414-6, 2003 Nov.
Artigo em Zh | MEDLINE | ID: mdl-14703470

RESUMO

OBJECTIVE: To reveal the stress distribution in the superstructure of fixed bridge supported by tooth-implant in the process of mastication for improvement of denture design. METHODS: The stress distribution and displacement of the superstructure were studied and analyzed by means of CT Scan, CAD and three-dimensional finite element when various loads were applied. RESULTS: (1) The stress distribution in abutments under oblique loads at forty-five degrees was uneven and the peak value was 4 - 6 times higher than that under vertical loads. Stress concentration occurred with significant compressive stress. (2) Compressive stress widely distributed in the middle area of occlusal surface of pontic, whose peak value under concentrated loads was significantly higher than that under disperse loads. The loading direction had no effect on the stress concentration. (3) The maximum displacement of implant abutment in medial-distal direction was greater than that of the neck of nature tooth. CONCLUSIONS: The mechanic complications of superstructure could be prevented by reducing oblique loads and concentrated ones. It is certain that the further improvements of curve-resistance of pontics and press-resistance of abutments are available.


Assuntos
Implantes Dentários , Análise do Estresse Dentário , Análise de Elementos Finitos , Prótese Parcial Fixa , Humanos
19.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 39(6): 467-70, 2004 Nov.
Artigo em Zh | MEDLINE | ID: mdl-15854316

RESUMO

OBJECTIVE: To study the feasibility of diagnosing parotid disease with magnetic resonance sialography (MRS) and to select the optimal scanning sequence. METHODS: Twenty-three patients with parotid gland disease and 5 normal adults received sialography using magnetic resonance imaging technique and several sequences (including IR-FSE, FSE, SS-IR-FSE, SS-FSE) were used. After first scanning, the patients were scanned respectively 3 and 10 minutes after buccal application of vitamin C. And MR images of duct obtained. The images of parotid duct system were analysed and evaluated according to their displaying effects. Qualitative diagnosis was made based on MRI and those diagnosis were compared with pathological diagnosis after operation. RESULTS: Images of MR sialography clearly displayed the main duct and its branches of parotid gland and the pathological changes of duct, such as narrow, expanded, stoppage. Of the scanning sequences, IR-FSE was superior to others in manifesting the parotid gland duct (P < 0.05). The performance of images after being given vitamin C did not significantly improve the displaying effect. The accurate rate of qualitative diagnosis was 95.6%. CONCLUSIONS: MR sialography can clearly display the parotid ducts and their pathological changes. The accurate rate of qualitative diagnosis of parotid disease was higher than that X-ray sialography.


Assuntos
Imageamento por Ressonância Magnética/métodos , Doenças Parotídeas/diagnóstico , Sialografia/métodos , Adolescente , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ductos Salivares/patologia , Adulto Jovem
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