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1.
Bioelectrochemistry ; 157: 108659, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38330530

RESUMO

The issue of material failure attributed to microbiologically influenced corrosion (MIC) is escalating in seriousness. Microorganisms not only facilitate corrosion but certain beneficial microorganisms also impede its occurrence. This study explored the impact of marine B. velezensis on the corrosion behavior of X65 steel in simulated offshore oilfield produced water. B. velezensis exhibited rapid growth in the initial stages, and the organic acid metabolites were found to promote corrosion. Subsequently, there was an increase in cross-linked "networked" biofilms products, a significant rise in the prismatic shape of corrosion products, and a tendency for continuous development in the middle and late stages. The organic/inorganic mineralized film layer formed on the surface remained consistently complete. Metabolic products of amino acid corrosion inhibitors were also observed to be adsorbed into the film. B. velezensis altered the kinetics of the X65 steel cathodic reaction, resulting in a deceleration of the electrochemical reaction rate. The mineralization induced by B. velezensis effectively slowed down the corrosion rate of X65 steel.


Assuntos
Bacillus , Aço , Aço/química , Água , Corrosão , Biomineralização , Campos de Petróleo e Gás , Biofilmes
2.
BMJ ; 381: e073043, 2023 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-37164365

RESUMO

OBJECTIVE: To explore inequalities in human resources for health (HRH) in relation to all cause and cause specific mortality globally in 1990-2019. DESIGN: Observational study. SETTING: 172 countries and territories. DATA SOURCES: Databases of the Global Burden of Disease Study 2019, United Nations Statistics, and Our World in Data. MAIN OUTCOME MEASURES: The main outcome was age standardized all cause mortality per 100 000 population in relation to HRH density per 10 000 population, and secondary outcome was age standardized cause specific mortality. The Lorenz curve and the concentration index (CCI) were used to assess trends and inequalities in HRH. RESULTS: Globally, the total HRH density per 10 000 population increased, from 56.0 in 1990 to 142.5 in 2019, whereas age standardized all cause mortality per 100 000 population decreased, from 995.5 in 1990 to 743.8 in 2019. The Lorenz curve lay below the equality line and CCI was 0.43 (P<0.05), indicating that the health workforce was more concentrated among countries and territories ranked high on the human development index. The CCI for HRH was stable, at about 0.42-0.43 between 1990 and 2001 and continued to decline (narrowed inequality), from 0.43 in 2001 to 0.38 in 2019 (P<0.001). In the multivariable generalized estimating equation model, a negative association was found between total HRH level and all cause mortality, with the highest levels of HRH as reference (low: incidence risk ratio 1.15, 95% confidence interval 1.00 to 1.32; middle: 1.14, 1.01 to 1.29; high: 1.18, 1.08 to 1.28). A negative association between total HRH density and mortality rate was more pronounced for some types of cause specific mortality, including neglected tropical diseases and malaria, enteric infections, maternal and neonatal disorders, and diabetes and kidney diseases. The risk of death was more likely to be higher in people from countries and territories with a lower density of doctors, dentistry staff, pharmaceutical staff, aides and emergency medical workers, optometrists, psychologists, personal care workers, physiotherapists, and radiographers. CONCLUSIONS: Inequalities in HRH have been decreasing over the past 30 years globally but persist. All cause mortality and most types of cause specific mortality were relatively higher in countries and territories with a limited health workforce, especially for several specific HRH types among priority diseases. The findings highlight the importance of strengthening political commitment to develop equity oriented health workforce policies, expanding health financing, and implementing targeted measures to reduce deaths related to inadequate HRH to achieve universal health coverage by 2030.


Assuntos
Saúde Global , Malária , Recém-Nascido , Humanos , Causas de Morte , Recursos Humanos , Mão de Obra em Saúde
3.
Bioelectrochemistry ; 143: 107951, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34601262

RESUMO

Microbiologically influenced corrosion (MIC) is a complex process involving the cooperative effect of different bacterial species that coexist in the biofilm. Early studies focused on the MIC of single bacterial communities. However, in natural and industrial fields, biofilms are mostly composed of a variety of species. In this work, the effect of interspecific interaction on corrosion of X65 steel was investigated through the mixed culture of sulfate reducing bacteria (SRB) and iron oxidizing bacteria (IOB). Results demonstrated that the mixed microbial consortia created a cooperative effect to aggravate the local corrosion of X65 steel. Compared with the single species, the presence of IOB increased the growth activity of SRB cells and promoted the role of SRB in steel corrosion. The corrosion form on the surface of X65 steel gradually changed to annular pits induced by anaerobic SRB. The succession of dominant bacteria and the development of mixed species biofilm led to an increase in corrosion rate and local corrosion. The corrosion mechanism of X65 steel by mixed species biofilm at different stages was carefully elucidated.


Assuntos
Aço
4.
Carbohydr Polym ; 265: 118082, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33966846

RESUMO

Surfaces engineered to identify and enrich glycoproteins are of considerable interest in the diagnostic and detection fields. A boronate affinity (BA) material was proposed as a potential candidate for the isolation of glycoproteins. However, this material has the disadvantages of low efficiency and non-degradability. Herein, a novel dendrimer-amplified BA cellulose foam (PEI-PBA-CF) was fabricated via a mild two-step approach. The as-prepared PEI-PBA-CF exhibited a rapid adsorption equilibrium rate (within 60 min) and outstanding adsorption capacity for horseradish peroxidase (537.4 mg g-1) and ovalbumin (495.5 mg g-1). Furthermore, competitive adsorption experiments demonstrated that PEI-PBA-CF could achieve selective separation and purification of glycoproteins from complex biological samples due to the synergistic effect of the improved BA capacity by the dendrimer and the well-interconnected porous structure of the biomass matrix. Consequently, these cellulose foams might present new application opportunities in analytical and biomedical fields.


Assuntos
Ácidos Borônicos/química , Celulose/química , Dendrímeros/química , Glicoproteínas/isolamento & purificação , Adsorção , Clara de Ovo/química , Glicoproteínas/química , Peroxidase do Rábano Silvestre/química , Humanos , Ovalbumina/química , Polietilenoimina/química , Porosidade , Bases de Schiff/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
5.
Carbohydr Polym ; 262: 117923, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33838802

RESUMO

Flexible electronics products have attracted wide attention because of their excellent flexibility, conductivity and stability. In this study, the liquid phase reduction method was used to in situ reduce fractal-structured silver particles (FSSPs) on cellulose surface to prepare conductive paper with excellent conductivity, and good stability and flexibility. The experimental results show that when the mass ratio of silver to cellulose was 1.5:1, the sheet resistance of conductive paper is as low as 0.02 Ω·sq-1, and the conductivity reaches 1041.33 S cm-1, which shows excellent conductivity. In order to expand the application of conductive paper in the field of flexible wearable electronic products, the mechanical stability and oxidation resistance of conductive paper were tested. The results show that the conductive paper has good stability and is expected to replace the flexible electronics products made of plastic.


Assuntos
Celulose/química , Nanocompostos/química , Prata/química , Fibra de Algodão , Condutividade Elétrica , Eletrodos , Eletrônica , Fractais , Humanos , Fenômenos Mecânicos , Oxirredução , Papel , Resistência à Tração , Dispositivos Eletrônicos Vestíveis
6.
Chemistry ; 16(43): 12935-40, 2010 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-20878798

RESUMO

A new family of artificial transcription factor (ATF)-based conjugates have been designed and synthesized as potent chemical nucleases. Polyamides as the important and efficient ATFs were used to modify and activate several anchor compounds. The results demonstrate that the resulting conjugates remarkably promote the rate accelerations and non-random double-strand DNA cleavage activity. Interestingly, the cleavage activity of both the hydrolytic and oxidative agents was promoted efficiently through the modification of the ATFs.


Assuntos
Clivagem do DNA , DNA/química , Nylons/química , Fatores de Transcrição/síntese química , Fatores de Transcrição/metabolismo , Desenho de Fármacos , Modelos Moleculares , Estrutura Molecular , Conformação de Ácido Nucleico , Oxirredução , Fatores de Transcrição/química
7.
Bioresour Technol ; 316: 123882, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32739576

RESUMO

Lignocellulosic biomass fractionaion into its three major components is critically important for efficient feedstock utilization. The hydrothermal-ethanol method has broad application as its first step, hydrothermal treatment, provides high hemicellulose separation efficiency. However, it severely inhibits the delignification on the subsequent ethanol extraction. In this study, the second step, ethanol extraction, was facilitated by the addition of 3% NaOH and 3% H2O2, resulting in a significant improvement of lignin separation (by 48.2%). SEM, AFM, XPS, and XRD were used to characterize the surface composition of the remaining solids (crude cellulose) while the structure of isolated lignin was characterized by FT-IR, CP/MAS 13C NMR, GPC and TGA. The lignin samples isolated with both facilitated and non-facilitated ethanol extraction were compared to elucidate the lignin removal mechanism. The results showed that lignin degradation and crosslinking/polymerization occur in parallel during both the hydrothermal treatment and ethanol extraction.


Assuntos
Etanol , Triticum , Peróxido de Hidrogênio , Hidrólise , Lignina , Espectroscopia de Infravermelho com Transformada de Fourier
8.
J Vet Med Sci ; 81(2): 177-181, 2019 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-30531130

RESUMO

A 3.9-year-old female African pygmy hedgehog (Atelerix albiventris) had a firm, tan-colored mass with an uneven surface arising from the mandibular salivary gland. A histopathologic examination revealed that the mass was composed of neoplastic proliferation of epithelial and spindle cells. The neoplastic spindle cells showed positive for vimentin, smooth muscle actin, calponin and cytokeratin 14 and, negative for cytokeratin 19, suggesting that spindle cells were derived from myoepithelial cells. Based on the histological findings and immunohistochemistry results, the mass was diagnosed as pleomorphic adenoma. Pleomorphic adenoma is the most common benign tumor found in human salivary glands, but it is rare in animals. To the best of our knowledge, this is the first report of pleomorphic adenoma in hedgehogs.


Assuntos
Adenoma Pleomorfo/veterinária , Ouriços , Neoplasias das Glândulas Salivares/veterinária , Adenoma Pleomorfo/patologia , Animais , Feminino , Neoplasias das Glândulas Salivares/patologia , Glândulas Salivares/patologia
9.
Am J Dent ; 21(4): 210-4, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18795515

RESUMO

PURPOSE: To evaluate the efficacy of a dentifrice containing calcium sodium phosphosilicate (NovaMin) study versus a placebo and a commercially-available SrCl2 containing dentifrice for the treatment of dentin hypersensitivity. METHODS: This was a 6-week, randomized, parallel-arm, double-blind clinical study. 71 subjects ranging in age from 21 to 56 years old completed the study. Evaporative and thermal stimuli were used to measure pain using a VAS scale. Measurements were obtained at baseline, 2 weeks and 6 weeks. RESULTS: The placebo and the NovaMin groups showed a statistically significant decrease in sensitivity by both measures after 6 weeks (P < 0.05). The SrCl2 group showed a statistically significant decrease from baseline at the 2-week time point, but not at the 6-week time point for the evaporative stimulus. The percent reduction in sensitivity at 6 weeks for the NovaMin test group was 35% for air and 39% for cold water stimulus, versus 11% for air and 22% for cold water for the SrCl2 paste. The reductions for the placebo paste were 21% for the air stimulus and 18% for water. A cross tabulation measure of the reduction in sensitivity at each time point for all three treatments showed that the NovaMin product was more effective than either of the other products. For the air stimulus in the NovaMin group, 58% of subjects improved at each time point compared with 26% for the SrCl2 group and 20% for the placebo group. These results demonstrate that the NovaMin dentifrice was more effective at reducing sensitivity compared with a commercial dentifrice and placebo control.


Assuntos
Dentifrícios/uso terapêutico , Sensibilidade da Dentina/tratamento farmacológico , Vidro , Adulto , Ar , Apatitas/química , Materiais Biocompatíveis/química , Fosfatos de Cálcio/uso terapêutico , Carbonatos/química , Temperatura Baixa , Método Duplo-Cego , Feminino , Seguimentos , Vidro/química , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Medição da Dor , Placebos , Silicatos/uso terapêutico , Estrôncio/uso terapêutico , Fatores de Tempo , Escovação Dentária/instrumentação
10.
Curr Med Sci ; 38(3): 524-529, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30074222

RESUMO

The purpose of this study was to determine the ion release from four commercially available pit-and-fissure sealants [3M Clinpro, 3M Concise™, BeautiSealant (BS), and GI FX-II)]. With each brand, 18 specimens were prepared. Their fluoride release in de-ionized water was measured by fluoride electrode, while the release of silicate (Si), aluminum (Al), sodium (Na), calcium (Ca), strontium (Sr), and phosphorus (P) was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) on days 1, 3, 7, 14, 21, and 28. The result showed that fluoride was not released from 3M Concise™. GI FX-II displayed the largest fluoride release, which, however, dropped rapidly on day 3. 3M Clinpro exhibited less fluoride release than GI FX-II and BS did. At any time during the 28-day experimental period, GI FX-II released more Na than the other sealants (P<0.001). BS ranked the second in Na release, and a small amount of Na ions was released from the 3M Clinpro and 3M Concise™ samples. Al ions were only detected from BS and GI FX-II, but not from the 3M Clinpro and 3M Concise™. Additionally GI FX-II had the largest Si release among the four brands at any time during the experimental period (P<0.001). Ca ions were detected from 3M Clinpro and 3M Concise™, but not from GI FX-II. BS released more Sr than the other sealants at any time during the experimental period (P<0.001). All the samples released similar amounts of P continuously during these 28 days. In conclusion, based on the type and the amount of ion release, BS is the best pit-and-fissure sealant among the four brands.


Assuntos
Íons/análise , Selantes de Fossas e Fissuras/análise , Elementos Químicos , Fluoretos/análise
11.
Nanoscale ; 10(16): 7526-7535, 2018 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-29637947

RESUMO

Although the synthesis and fluorescent properties of lanthanide-amino acid complex nanostructures have been investigated extensively, limited studies have been reported on metal ions' substitution ability for the lanthanide ions in the complex and their effect on the fluorescent property. In this study, taking biocompatible Tb-aspartic acid (Tb-Asp) complex nanocrystals as a model, the substitution mechanism of metal ions, particularly transition metals, for Tb ions in Tb-Asp nanocrystals and the change in the fluorescent property of the Tb-Asp nanocrystals after substitution were systematically investigated. The experimental results illustrated that metal ions with higher electronegativity, higher valence, and smaller radius possess stronger ability for Tb ions' substitution in Tb-Asp nanocrystals. Based on the effect of substituting ions' concentration on the fluorescent property of Tb-Asp, a facile method for copper ions detection with high sensitivity was proposed by measuring the fluorescent intensity of Tb-Asp nanocrystals' suspensions containing different concentrations of copper ions. The good biocompatibility, great convenience of synthesis and sensitive detection ability make Tb-Asp nanocrystals a very low cost and effective material for metal ions detection, which also opens a new door for practical applications of metal-Asp coordinated nanocrystals.


Assuntos
Ácido Aspártico/química , Materiais Biocompatíveis/química , Cobre/análise , Nanopartículas/química , Fluorescência , Íons/análise , Elementos da Série dos Lantanídeos
12.
Chin J Dent Res ; 21(4): 241-247, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30264040

RESUMO

OBJECTIVE: To assess the current periodontal status of 35 to 44-year-olds from the Chinese population and to analyse potential influence factors on periodontal disease. METHODS: The data of subjects were collected from both urban and rural areas of all 31 provinces, autonomous regions and municipalities of the mainland of China, as part of the 4th National Oral Health Survey. All subjects were aged 35 to 44 years old. In total, 4,410 subjects were enrolled in the present study. Each subject was asked to undergo a professional oral examination and to fill in a questionnaire. Periodontal health status was evaluated by probe bleeding, calculus, periodontal pocket depth and clinical attachment loss. The data were analysed using the chi-square test and binary logistic regression analysis. RESULTS: The prevalence of probe bleeding and calculus was 87.4% and 96.7% respectively among the 35 to 44-year-old population. Prevalence of shallow pockets (4 mm ≤ PD < 6 mm) and deep pockets (PD ≥ 6 mm) was 45.8% and 6.9% respectively among 35 to 44-year-old people. In addition, prevalence of clinical attachment loss (CAL > 3 mm) was 33.2%. Gender, educational level, smoking, teeth brushing frequency, dental floss and toothpick use were found relevant to periodontal condition. CONCLUSION: Periodontal disease was highly prevalent among 35 to 44-year-old Chinese adults. Gender, educational level, smoking, teeth brushing frequency, toothpick and dental floss use could be potential influence factors of periodontal health status.


Assuntos
Cálculos Dentários/epidemiologia , Escolaridade , Doenças Periodontais/epidemiologia , Bolsa Periodontal/epidemiologia , Fumar/epidemiologia , Escovação Dentária/estatística & dados numéricos , Adulto , China/epidemiologia , Dispositivos para o Cuidado Bucal Domiciliar , Inquéritos de Saúde Bucal , Feminino , Hemorragia Gengival/epidemiologia , Humanos , Modelos Logísticos , Masculino , Higiene Bucal/estatística & dados numéricos , Prevalência , Fatores de Risco , Fatores Sexuais
13.
Chin J Dent Res ; 21(3): 167-179, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30255168

RESUMO

OBJECTIVE: To investigate the prevalence and severity of dental caries among pre-school children in China as part of the 4th National Oral Health Survey. METHODS: The sampling process was conducted with a multistage stratified cluster method. A total of 40,360 children aged between 3 and 5 years were recruited for this study. Each participant was clinically assessed according to the 5th edition of the oral health survey's basic methods recommended by the World Health Organization (WHO) and their parents or grandparents completed a questionnaire at a face-to-face interview. The status of dental caries was shown in the form of the mean dmft and the prevalence of dental caries. The logistic regression analysis was performed to study the relationships between the prevalence of dental caries and the selected variables. RESULTS: The prevalence of dental caries was 50.8%, 63.6% and 71.9% for 3-, 4- and 5-year-olds, respectively. The mean dmft was 2.28, 3.40 and 4.24, respectively. Logistic regression analysis showed that children who were mixed-fed had a higher chance of staying free of dental caries; children who had dessert before going to bed were associated with a higher probability of caries. CONCLUSION: The status of dental caries among preschool children in China is on the increase. The preschoolers' dental caries status related to their breastfeeding conditions within the first 6 months of life and their snacking habits.


Assuntos
Aleitamento Materno/estatística & dados numéricos , Cárie Dentária/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Fórmulas Infantis/estatística & dados numéricos , Pais , Pré-Escolar , China/epidemiologia , Estudos Transversais , Índice CPO , Inquéritos de Saúde Bucal , Escolaridade , Feminino , Humanos , Renda/estatística & dados numéricos , Modelos Logísticos , Masculino , Refeições , Prevalência , Fatores de Risco , População Rural/estatística & dados numéricos , Índice de Gravidade de Doença , Escovação Dentária/estatística & dados numéricos , População Urbana/estatística & dados numéricos
14.
Eur J Endocrinol ; 177(2): 195-205, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28566441

RESUMO

OBJECTIVE: We assessed the efficacy and safety of a weekly pegylated human growth hormone (PEG-rhGH) (Jintrolong) vs daily rhGH for children with growth hormone deficiency (GHD). DESIGN: Phase II and III, multicenter, open-label, randomized controlled trials. METHODS: 108 and 343 children with treatment-naive GHD from 6 hospitals in China were enrolled in the phase II and III studies respectively. Patients in the phase II study were randomized 1:1:1 to weekly Jintrolong (0.1 mg/kg/week PEG-rhGH complex), weekly Jintrolong (0.2 mg/kg/week PEG-rhGH complex) or daily rhGH (0.25 mg/kg/week) for 25 weeks. Patients in the phase III study were randomized in a 2:1 ratio to weekly Jintrolong (0.2 mg/kg/week) or daily rhGH (0.25 mg/kg/week) for 25 weeks. The primary endpoint for both studies was height velocity (HV) increase at the end of treatment. Other growth-related parameters, safety and compliance were also monitored. RESULTS: The phase II study established the preliminary efficacy, safety and recommended dose of Jintrolong PEG-rhGH. In the phase III study, we demonstrated significantly greater HV increases in patients receiving Jintrolong treatment (from 2.26 ± 0.87 cm/year to 13.41 ± 3.72 cm/year) vs daily rhGH (from 2.25 ± 0.82 cm/year to 12.55 ± 2.99 cm/year) at the end of treatment (P < 0.05). Additionally, significantly greater improvement in the height standard deviation scores was associated with Jintrolong throughout the treatment (P < 0.05). Adverse event rates and treatment compliance were comparable between the two groups. CONCLUSION: Jintrolong PEG-rhGH at a dose of 0.2 mg/kg/week for 25 weeks is effective and safe for GHD treatment and is non-inferior to daily rhGH.


Assuntos
Nanismo Hipofisário/diagnóstico , Nanismo Hipofisário/tratamento farmacológico , Hormônio do Crescimento Humano/análogos & derivados , Polietilenoglicóis/administração & dosagem , Adolescente , Criança , Preparações de Ação Retardada/administração & dosagem , Nanismo Hipofisário/sangue , Feminino , Hormônio do Crescimento Humano/administração & dosagem , Humanos , Masculino , Proteínas Recombinantes/administração & dosagem
15.
Chin J Dent Res ; 18(3): 177-83, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26485510

RESUMO

OBJECTIVE: To evaluate the development and risk factors of white spot lesions (WSLs) in orthodontic patients with fixed appliances in a Chinese population. METHODS: A total of 202 subjects participated in the cross-sectional study. Clinical examination of the state of the entire labial (buccal) enamel surface was conducted under artificial light using a clinical mirror and an explorer. A face-to-face interview was conducted through a structured questionnaire to collect a range of information, including demographic data, family income, level of education, toothbrushing frequency, fluoride toothpaste usage and the use of a professional toothbrush (V type). RESULTS: WSLs appeared on 57.9% of the subjects after orthodontic treatment with fixed appliances; the mean tooth number of WSLs was 4.8. A higher prevalence was observed in subjects whose time of therapy was 17 months or longer (OR = 3.2, P < 0.050), and who had modified their unhealthy dietary habits (OR = 3.7, P < 0.001). Younger individuals or individuals who consumed food with sugar at least once a day during the course of their orthodontic treatment also exhibited a higher likelihood of experiencing WSLs. CONCLUSION: The prevalence of WSLs after orthodontic treatment with fixed appliances was relatively high in China. Clinicians should be aware of the risk factors of WSLs that may occur during the treatment period.


Assuntos
Braquetes Ortodônticos/efeitos adversos , Adolescente , Adulto , China , Estudos Transversais , Feminino , Humanos , Masculino , Fatores de Risco , Inquéritos e Questionários , Adulto Jovem
16.
Mater Sci Eng C Mater Biol Appl ; 38: 39-45, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24656350

RESUMO

Hexagonal Ag nanoplates (NPs) were synthesized by polyvinylpyrrolidone (PVP) and trisodium citrate (TSC) which selectively absorbed to Ag (100) and Ag (111) surfaces, then were anchored to graphene (GN) to form novel Ag NPs/GN composite. The thickness of Ag NPs is ~4 nm and the length is 18-66 nm. Transmission electron microscopy (TEM) image shows that the plates are f-c-c crystals containing {111} facets on their two planar surfaces. Zeta potential indicated that the surface of Ag NPs/GN is negatively charged while vanillin is positively charged. Thus Ag NPs/GN modified on glass carbon electrodes (GCE) allowed abundant adsorption for vanillin and electron transfer between vanillin and Ag NPs/GN/GCE. Square wave voltammetry (SWV) results indicated that the over potential on Ag NPs/GN/GCE negatively shifts 52 mV than that on Ag NPs/GCE. Ag NPs/GN with enhanced surface area and good conductivity exhibited an excellent electrocatalytic activity toward the oxidation of vanillin. The corresponding linear range was estimated to be from 2 to 100 µM (R(2)=0.998), and the detection limit is 3.32×10(-7) M (S/N=3). The as-prepared vanillin sensor exhibits good selectivity and potential application in practical vanillin determination.


Assuntos
Benzaldeídos/análise , Técnicas Eletroquímicas/métodos , Grafite/química , Nanopartículas Metálicas/química , Prata/química , Calibragem , Carbono/química , Fenômenos Químicos , Eletrodos , Vidro/química , Nanopartículas Metálicas/ultraestrutura , Microscopia de Força Atômica , Povidona/química , Espectrofotometria Ultravioleta
17.
Int J Oral Sci ; 4(3): 157-60, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22699265

RESUMO

To obtain the caries experience and, plaque accumulation severity and pit and fissure morphology in first permanent molars in 7-8 children in Wuhan, as a reasonable prediction of caries risk and preventive attention in the future, a convenient sample of five primary schools in the vicinity of the Wuhan University School and Hospital of Stomatology was drawn. Two calibrated examiners orally examined all present grade 2 children in the classroom, using standard caries plaque and tooth morphology criteria. Dental caries was scored at enamel (D(2)) and dentine (D(3)) for tooth and surface level. Independent variables were age, gender and school. Data analysis used analysis of variance and t-test. The sample comprised 1 043 7- and 8-year-olds. The prevalence of dental caries in permanent dentition was 8.7% and in primary dentition, 68.7%. Mean Decayed, Missing, Filled Teeth/S (DMFT/S) scores were 0.11 and 0.14, respectively. Mean dmft/s scores were 2.8 and 5.0. The d-component constituted 75% of the d(3)mft index, while enamel carious lesions constituted 36% of the total number of carious lesions (d(2,3)-component). Prevalence of medium and deep pits and fissures was 84.6%. Prevalence of medium and severe plaque accumulation was 67.4%. Prevalence of dental caries in the deciduous and permanent dentitions of 7- to 8-year-old children was high. Deep pits and fissures in high caries risk children should be sealed.


Assuntos
Cárie Dentária/epidemiologia , Cárie Dentária/prevenção & controle , Fissuras Dentárias/patologia , Dente Molar/patologia , Criança , China/epidemiologia , Índice CPO , Esmalte Dentário/patologia , Índice de Placa Dentária , Dentina/patologia , Dentição Permanente , Feminino , Humanos , Masculino , Prevalência , Dente Decíduo
18.
J Biotechnol ; 157(1): 198-206, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22100268

RESUMO

Pichia pastoris is a methylotropic yeast that has gained great importance as an organism for protein expression in recent years. Here, we report the expression of recombinant human erythropoietin (rhEPO) in glycoengineered P. pastoris. We show that glycosylation fidelity is maintained in fermentation volumes spanning six orders of magnitude and that the protein can be purified to high homogeneity. In order to increase the half-life of rhEPO, the purified protein was coupled to polyethylene glycol (PEG) and then compared to the currently marketed erythropoiesis stimulating agent, Aranesp(®) (darbepoetin). In in vitro cell proliferation assays the PEGylated protein was slightly, and the non-PEGylated protein was significantly more active than comparator. Pharmacodynamics as well as pharmacokinetic activity of PEGylated rhEPO in animals was comparable to that of Aranesp(®). Taken together, our results show that glycoengineered P. pastoris is a suitable production host for rhEPO, yielding an active biologic that is comparable to those produced in current mammalian host systems.


Assuntos
Eritropoetina/biossíntese , Pichia/metabolismo , Engenharia de Proteínas/métodos , Animais , Proliferação de Células/efeitos dos fármacos , Darbepoetina alfa , Eritropoetina/análogos & derivados , Eritropoetina/sangue , Eritropoetina/genética , Eritropoetina/farmacocinética , Eritropoetina/farmacologia , Feminino , Glicosilação , Humanos , Masculino , Camundongos , Pichia/genética , Polietilenoglicóis , Polissacarídeos/química , Ratos Sprague-Dawley , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
19.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 28(6): 626-8, 2010 Dec.
Artigo em Zh | MEDLINE | ID: mdl-21365839

RESUMO

OBJECTIVE: To describe the dental caries of 15-year-old adolescents in Hubei province, and to determine the influence of various social-behavioral risk factors on dental caries in the population. METHODS: The survey employed a multistage, stratified, non-geometric proportional randomized sampling, representing adolescents aged 15-year-old in Hubei province. The epidemiological investigation of dental caries was made by clinical oral health examination. Oral health knowledge, attitude and behavior investigated by questionnaire. RESULTS: The prevalence and mean DMFT in 1,080 15-year-old adolescents in Hubei province was 24.4% and 0.45, respectively. 11.4% of the adolescents brushed their teeth at least twice a day, 33.1% of the adolescents ever visited the dentists. A significant higher prevalence of dental caries was observed in girls (OR = 1.70). In addition, those who visit dentists and those who the scores of the consumption of sugar drink were high tended to have a higher prevalence of dental caries. CONCLUSION: The dental caries prevalence of adolescents in Hubei province is low, but oral health habit of adolescents seems poor. Gender and consumption of sugar drink may be risk factors of dental caries.


Assuntos
Cárie Dentária , Fatores de Risco , Adolescente , Feminino , Humanos , Masculino , Saúde Bucal , Prevalência , Inquéritos e Questionários
20.
Community Dent Oral Epidemiol ; 37(5): 391-8, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19624698

RESUMO

OBJECTIVES: To assess the outcome of oral health promotion in schoolchildren over a 3-year period in Yichang City, Hubei, China. METHODS: In a cluster randomized controlled trial, the concept of the World Health Organization Health Promoting Schools Project was applied to primary schoolchildren. Seven intervention schools and eight control schools were randomly selected from one district by stratified cluster sampling. The study was conducted as a 3-year follow-up study. After 3 years, 661 children remained in the intervention group and 697 children in the control group. Data on dental caries, plaque accumulation, and sulcus bleeding were collected by clinical examination, while behavioural data were gathered by self-administered questionnaires. RESULTS: The 3-year net mean DMFS increment score was 0.22 in the intervention schools and 0.35 in the control schools (P < 0.013). A statistically significant difference in mean plaque (P < 0.013) and sulcus bleeding (P < 0.005) increment scores after 3 years was found between the two groups. Statistically significant higher scores were observed in restorations received and sealants placed, and a lower score in untreated dental caries, in children from the intervention group than the control group after 3 years (P < 0.01). In addition, more children in the intervention schools adopted regular oral health behavioural practices such as brushing their teeth at least twice a day, visiting the dentist within the past calendar year, and using fluoride toothpaste. CONCLUSION: The study suggests that the school-based oral health promotion was an effective way to reduce new caries incidence, improve oral hygiene and establish positive oral health behavioural practices in the targeted schoolchildren.


Assuntos
Promoção da Saúde , Saúde Bucal , Instituições Acadêmicas , Criança , China , Análise por Conglomerados , Cárie Dentária/prevenção & controle , Índice de Placa Dentária , Restauração Dentária Permanente , Feminino , Humanos , Masculino , Selantes de Fossas e Fissuras , Estatísticas não Paramétricas , Escovação Dentária
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