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1.
Int J Biol Macromol ; : 134358, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39089560

RESUMO

A novel pH-triggered bilayer film was composed of zein (Z), carboxymethylcellulose (CMC), Eudragit L100 (L100), and purple cabbage anthocyanin (PCA), followed by casting for monitoring pork freshness during storage at 4 °C and 25 °C. This bilayer film was employed to encapsulate anthocyanins, preventing anthocyanins oxidation and photodegradation. Additionally, under pH 6, this film ruptures and releases anthocyanins, inducing a sudden color change in the indicator film, significantly reducing errors in freshness indications. Notably, the ZCLP8% film had excellent stability and pH response properties. The performance of the ZCLP8% film in monitoring pork freshness was evaluated. When the concentration of pork TVB-N reached 15.59 mg/100 g (pH = 6.35), the bilayer film was ruptured, and the release rate of PCA was 85.52 %, which was a significant change in the color of the bilayer film compared with that at pH = 5. Therefore, this work addresses the limitation that anthocyanin-based intelligent films are subject to judgment errors when applied, opening new possibilities for food freshness differentiation monitoring.

2.
Int J Biol Macromol ; 275(Pt 1): 133128, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38876237

RESUMO

This study aimed to develop an eco-friendly active biogenic nanocomposite film through the complexation of silver nanoparticles (AgNPs), berry wax (BYW), and chitosan (CT) for maintiaing rabbit functional meat freshness. AgNPs were synthesized using Chinese medicinal paeoniaceae petal extract, and they were loaded at various concentrations (0.5 %, 0.75 %, 1.0 %, 1.25 %, and 1.5 % based on CT w/w) into the CT/BYW complex. The AgNPs exhibited an average size of 55 nm and a zeta potential of -26.3 mV with a spherical shape. The particle size and zeta potential of the film dispersions were 370.5-529.5 nm and 40.17-49.345 mV, respectively. FTIR, SEM, and XRD results showed compatibility among AgNPs and CT/BYW structure. The film water vapor permeability and light transparency decreased from 6.5 to 3.5 and 10 to 0.78 %, respectively, while opacity increased from 1.76 to 9.96 % with increasing concentrations of AgNPs. Among them, the film composite CT/BYW/AgNPs1.5% had better antioxidant and antibacterial properties, which was then applied for rabbit meat preservation at 4 °C for 16 days of storage. CT/BYW/AgNPs1.25%-packed sample had lower values of TVB-N, TBARS, TVC, and pH with greater retention of color properties compared to the control sample, which describes its ability to maintain meat freshness.

3.
Heliyon ; 10(2): e24200, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38293353

RESUMO

Objective: The goal of this systematic review and meta-analysis was to assess whether the dimensions of the frontal air sinus correlate with skeletal malocclusion. Study selection: PubMed, Scopus, Embase, and Google Scholar were searched for relevant studies published up to May 23, 2023. The review included observational and retrospective studies that compared the dimensions of the frontal air sinus between different skeletal malocclusions. The PECOS method was used in this study ("Population, Exposure, Comparator, Outcome, and Study design"). The search was done using the following English keywords: "frontal sinus" OR "lateral cephalometric" OR "malocclusion" AND "surface area". Results: Seven studies were included, which involved 1101 participants, of whom 403 were class I, 375 were class II, and 323 were class III. These studies had a moderate risk of bias. The surface area of the frontal sinus in class III was significantly larger than in class I (standardized difference in means (SDM) = -0.971; 95 % CI = -1.147- -0.796; P < 0.001) and in class II (SDM = -1.535; 95 % CI = -1.732- -1.337; P < 0.001). Conclusion: Class III malocclusion is associated with a larger surface area of the frontal sinus compared to classes I and II.

4.
Food Chem X ; 21: 101054, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38162038

RESUMO

A ratiometric fluorescence sensor platform with easy-to-use and accurate is nanoengineered for NH3 quantitative detection and visual real-time monitoring of chicken freshness using smartphones. The ratiometric fluorescent probe formed by combining the zinc ion complex and carbon dots has a double-emitted fluorescence peak. The fluorescence intensity of the complex changed can be clearly observed with the increase of the concentration of ammonia solution under 365 nm wavelength excitation. In order to detect NH3 concentration in gaseous phase, a portable paper-based sensor was designed. The sensor had a good linear relationship with NH3 concentration ranging from 10.0 to 90.0 µmol/L and the LOD value was 288 nM. This fluorescent paper-based sensor was used to check the freshness of chicken breast refrigerated at 4 °C, revealed observable shifts from blue to green. The fluorescent paper-based sensor can detect NH3 concentration in real time and simplify the monitoring process of meat freshness while ensuring accuracy and stability.

5.
Int J Biol Macromol ; 261(Pt 2): 129821, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38286371

RESUMO

Chitosan (CT) is extensively applied in developing food packaging films due to its non-toxic, biodegradable, and good film-forming properties. But CT-based single polymer film has issues with poor physico-mechanical, thermal, and light barrier properties. Therefore, this study aimed to incorporate natural berry wax (BYW) at various concentrations (5 %, 10 %, 15 %, 20 %, and 25 %, wt%) into CT to improve the quality characteristics of CT film. The microstructure of the film matrix was effectively proven to be compatible with BYW through the utilization of SEM, XRD, and FTIR spectroscopy. The results demonstrated that the quality parameters of CT/BYW composite film were significantly affected by the increasing concentration of BYW. The integration of BYW with a concentration of 5 % to 20 % to CT substantially improved the film characteristics by reducing moisture content, swelling power, solubility, and water vapor permeability, increasing the film's opacity, thermal stability, and tensile strength as well as enhancing the biodegradable potential. Furthermore, CT/BYW films showed higher thermal stability and UV and visible light resistance compared to pure CT film. Taken together, the CT film with 20 % berry wax showed the best film characteristics and biodegradable potential, which could be promising for enhancing the shelf-life of various food products.


Assuntos
Quitosana , Quitosana/química , Frutas , Embalagem de Alimentos/métodos , Resistência à Tração , Solubilidade , Permeabilidade
6.
Food Chem X ; 20: 100885, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38144776

RESUMO

In this study, beef was marinated with different low-sodium salt substitutes and heated and aged by employing superheated steam roasting and traditional roasting to investigate the effects of the various substitutes on the physicochemical properties, texture profile, sensory properties, volatile compounds, microstructural characteristics, and safety of cured and aged beef. Twenty kilograms of beef were arbitrarily divided into five treatments and pickled with different low-sodium salt substitutes. The results revealed no significant differences in saltiness, physicochemical characteristics, texture profile, or volatile compounds between the T2 and T3 and T1 (100% NaCl, T1; 75% KCl + 25% NaCl, T2; 50% KCl + 50% NaCl, T3) samples. Furthermore, the T4 and T5 (50% NaCl + 25% KCl + 20% MgCl2 + 5% CaCl2, T4; 100% yeast extract, T5) samples had lower saltiness than the T1 sample. The plasmolysis percentage and osmotic pressure of the T2 and T3 samples were lower than those of the T1 sample. Therefore, reducing sodium by substituting NaCl with 50% KCl or 75% KCl maintained an acceptable sensory and safety profile for beef consumption.

7.
Arch Oral Biol ; 153: 105720, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37285682

RESUMO

OBJECTIVE: This study aimed to explore the key genes, metabolites, and pathways that influence periodontitis pathogenesis by integrating transcriptomic and metabolomic studies. DESIGN: Gingival crevicular fluid samples from periodontitis patients and healthy controls were collected for liquid chromatography/tandem mass-based metabolomics. RNA-seq data for periodontitis and control samples were obtained from the GSE16134 dataset. Differential metabolites and differentially expressed genes (DEGs) between the two groups were then compared. Based on the protein-protein interaction (PPI) network module analysis, key module genes were selected from immune-related DEGs. Correlation and pathway enrichment analyses were performed for differential metabolites and key module genes. A multi-omics integrative analysis was performed using bioinformatic methods to construct a gene-metabolite-pathway network. RESULTS: From the metabolomics study, 146 differential metabolites were identified, which were mainly enriched in the pathways of purine metabolism and Adenosine triphosphate binding cassette transporters (ABC transporters). The GSE16134 dataset revealed 102 immune-related DEGs (458 upregulated and 264 downregulated genes), 33 of which may play core roles in the key modules of the PPI network and are involved in cytokine-related regulatory pathways. Through a multi-omics integrative analysis, a gene-metabolite-pathway network was constructed, including 28 genes (such as platelet derived growth factor D (PDGFD), neurturin (NRTN), and interleukin 2 receptor, gamma (IL2RG)); 47 metabolites (such as deoxyinosine); and 8 pathways (such as ABC transporters). CONCLUSION: PDGFD, NRTN, and IL2RG may be potential biomarkers of periodontitis and may affect disease progression by regulating deoxyinosine to participate in the ABC transporter pathway.


Assuntos
Multiômica , Periodontite , Humanos , Periodontite/genética , Mapas de Interação de Proteínas/genética , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Biologia Computacional/métodos
8.
Int J Biol Macromol ; 239: 124198, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36996954

RESUMO

In order to investigate the sensitivity of anthocyanins from different plant origin as indicators for salmon freshness, nine plant anthocyanins were extracted and fabricated into colorimetric sensor arrays to detect NH3, trimethylamine (TMA), dimethylamine (DMA) to indicate salmon freshness. Rosella anthocyanin had the highest sensitivity for amines, ammonia and salmon. HPLC-MSS analysis indicated that Delphinidin-3 glucoside accounted for 75.48 % of the Rosella anthocyanin. UV-visible spectral analysis showed that the maximum absorbance band of Roselle anthocyanins for acid and alkaline forms were located at 525 nm and 625 nm which showed a relatively broader spectrum than other anthocyanins. An indicator film was fabricated by combining Roselle anthocyanin with agar and polyvinyl alcohol (PVA), which showed visible changes from red to green when employed to monitor the freshness of salmon stored at 4 °C. The ΔE value of Roselle anthocyanin indicator film was changed from 5.94 to >10. The ΔE value also can predict the chemical quality indicators of salmon effectively, especially with characteristic volatile components, and the predictive correlation coefficient was above 0.98. Therefore, the proposed indicating film showed great potential monitoring salmon freshness.


Assuntos
Antocianinas , Álcool de Polivinil , Animais , Álcool de Polivinil/química , Antocianinas/química , Salmão , Ágar , Embalagem de Alimentos , Colorimetria , Concentração de Íons de Hidrogênio
9.
Food Chem ; 408: 134948, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36528991

RESUMO

The identification of geographical origin is an important factor in assessing the quality of aromatic and medicinal seeds such as Black Mahlab (Monechma ciliatum). However, at present, there are no studies concerning Black Mahlab Seeds (BMSs). To identify the geographical origin of BMSs, we have used gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-NIR) combined with chemometrics. Chemometrics analysis showed that FT-NIR and GC-MS can be used to discriminate the geographical origin of BMSs. FT-NIR coupled with the partial least squares regression (PLSR) was applied to develop the calibration models. The calibration models had a coefficient of determination (Rc2) of 0.82 for coumarin and 0.81 for methyl salicylate. The prediction model (Rp2) values ranged from 0.83 for coumarin to 0.77 for methyl salicylate. Overall, the chemometrics presented correct classification, and PLSR accurately predicted the volatiles, with an RMSEP range of 0.9 to 0.16 for the two volatiles targeted.


Assuntos
Acanthaceae , Quimiometria , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Sementes/química
10.
Food Chem ; 368: 130783, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34399174

RESUMO

A smartphone-based colorimetric sensor array system was established for discrimination of rice varieties having different geographical origins. Purposely, aroma profiling of nine rice varieties was performed using solid-phase microextraction gas chromatography-mass spectrometry. Alcohols, aldehydes, alkanes, ketones, heterocyclic compounds, and organic acids represent the abundant compounds. Colorimetric sensor array system produced a characteristic color difference map upon its exposure to volatile compounds of rice. Discrimination of rice varieties was subsequently achieved using principal component analysis, hierarchical clustering analysis, and k-nearest neighbors. Rice varieties from same geographical source were clustered together in the scatter plot of principal component analysis and hierarchical clustering analysis dendrogram. The k-nearest neighbors algorithm delivered optimal results with discrimination rate of 100% for both calibration and prediction sets using sensor array system. The smartphone-based colorimetric sensor array system and gas chromatography technique were able to effectively differentiate rice varieties with the advantage of being simple, rapid, and low-cost.


Assuntos
Oryza , Compostos Orgânicos Voláteis , Colorimetria , Cromatografia Gasosa-Espectrometria de Massas , Odorantes/análise , Smartphone , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/análise
11.
Food Chem ; 335: 127646, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32731123

RESUMO

Carbon/ZnO coaxial microfibers were synthesized with the hypha of Penicillium expansum as low-cost and green template. The SEM images, XRD and Raman spectra were used to characterize the morphology and chemical components of the prepared microfibers. The formation of the coaxial structure could be attributed to the attachment of Zn2+ onto the hypha surface through coordination and electrostatic interactions. Sensing performance of the carbon/ZnO microfibers toward Dopamine (DA) were evaluated by dropping method. Results showed that the proposed sensor exhibited good selectivity, reproducibility, and stability with a detection limit of 0.106 µM. Two linear ranges were obtained from 0 to 50 and 50 to 300 µM. The practicality of the carbon/ZnO microfibers was supported by the successful detection of DA in pork with recovery ranging from 96.85% to 104.51%. Based on the excellent electrochemical performance and easy preparation, the proposed sensor provides a promising method for determination of DA.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Carbono/metabolismo , Dopamina/análise , Hifas/metabolismo , Carne/análise , Penicillium/metabolismo , Óxido de Zinco/química , Óxido de Zinco/metabolismo , Animais , Técnicas Biossensoriais/instrumentação , Hifas/crescimento & desenvolvimento , Penicillium/crescimento & desenvolvimento , Suínos
12.
Food Sci Biotechnol ; 29(2): 217-226, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32064130

RESUMO

The marketability of blueberries over long distances has been limited because of their highly perishability. To prolong the postharvest shelf life and conserve quality properties of blueberry, various alternatives have been evaluated. We studied the influence of gum arabic (GA) alone or GA enhanced with African baobab (AB) fruit extract on blueberry during cold storage (4 °C) for 21 days. Physico-chemical properties (e.g. pH, color, firmness, and weight loss), microbial decay, antioxidant properties, polyphenol oxidase (PPO) and peroxidase (POD) activity were investigated. The fruit treated with GA combined AB indicated a significant delay in microbial decay, firmness loss, weight loss, and color change. The treatments on blueberries resulted in better preservation of total phenols and total anthocyanins delayed the increase in total soluble solids as compared to the control. The coatings lowered the activities of PPO and POD enzymes and delayed microbial decay in coated blueberry during 21 days of storage.

13.
Carbohydr Polym ; 224: 115141, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472839

RESUMO

Gums are a class of naturally occurring polysaccharides/carbohydrate polymers derived from renewable sources, which have the capacity to hydrate in water either by forming a gel or stabilizing emulsion systems. Among the substitutes recently considered to replace the application of petroleum-derived polymers against postharvest diseases and shelf life extension, gums and their derivatives have been considered as promising biocontrol products. Polysaccharide gum coatings provide a semipermeable barrier on the surface of produce to reduce respiration rate, weight loss and maintain the nutritional value. Gums have been used as excellent vehicles for active substances, also controlling the speed of diffusion of these, and improving the control of the maturation of fruit and vegetable. Additionally, plant extracts, essential oils, phenolic compounds, and vitamins can be incorporated into polysaccharides edible coatings in order to improve their mechanical barrier, antioxidant and antimicrobial properties. Gums have many advantages over the synthetic polymers, because they have been approved as GRAS by FAO, and their use is safe for the consumer and eco-friendly. This review aims to highlight the most relevant and current information in the use of polysaccharides in postharvest shelf life extension and preservation of overall quality of fruits and vegetables.


Assuntos
Filmes Comestíveis , Conservação de Alimentos/métodos , Frutas , Gomas Vegetais/química , Verduras , Qualidade dos Alimentos
14.
Chemosphere ; 230: 559-566, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31125884

RESUMO

Large volume of multidimensional data can be summarised, both in terms of tabulated statistics, and as graphic geospatial visualisations. The latter approach allows rapid interpretation and communication of complex information to stake-holders such as regulators, risk assessors and policy makers. In the main study on polychlorinated naphthalene (PCN), individual samples representing different edible fish species were analysed from around the UK. PCNs were observed in all samples with nearly all of the twelve measured congeners being detected. Summed congener concentrations ranged from 0.7 ng/kg ww (turbot) to 265 ng/kg ww (sprats). The highest contamination levels were recorded for sprats and mackerel with mean summed concentrations of 67 ng/kg ww and 68 ng/kg ww respectively. Two ancillary studies, on potentially toxic elements (PTEs) in crabs from China and aflatoxin in children's blood from Tanzania, demonstrate the wide applicability of this approach. The PTE contents in crab showed strong dependence on the tested tissues and elements, and crabs from Tai and Yangcheng Lakes showed obviously higher PTE levels than the other lakes. Geospatial distribution of the aflatoxin biomarker AF-alb in children's serum from 3 locations showed how individual anthropometric or socio-economic data reveals the relationship between family size, socio-economic score and magnitude of serum aflatoxin levels. In addition to facilitating the flow of interpreted data to stakeholders, these techniques can direct the formulation of risk mitigation activities and help with the identification of data gaps. When combined with hierarchical cluster analyses, correlations within the data can also be predicted.


Assuntos
Aflatoxinas/sangue , Monitoramento Ambiental/métodos , Contaminação de Alimentos/análise , Substâncias Perigosas/análise , Naftalenos/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise , Animais , Biomarcadores/sangue , Braquiúros/química , Criança , China , Sistemas de Informação Geográfica , Substâncias Perigosas/sangue , Humanos , Lagos/análise , Análise Espacial , Tanzânia , Poluentes Químicos da Água/sangue
15.
Chemosphere ; 195: 727-734, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29289018

RESUMO

Some commonly consumed marine fish species are considered to display a higher risk of bio-accumulating organic environmental contaminants such as PBDEs. As part of a study to investigate the spatial distribution of these contaminants, data on polybrominated diphenlyethers (PBDEs) and polybrominated biphenyls (PBBs) were collected and analysed by introducing a web-based resource which enables efficient spatial, species and concentration level representations. Furthermore, hierarchical cluster analyses permits correlations within the data to be predicted. The data provide current information on levels of PBDE and PBB occurrence, allowing identification of locations that show higher contaminant levels. 135 fish samples of various species were analysed from UK marine waters, but encompassing the waters around Norway in the North and to the Algarve in the South. PBDEs were observed in all samples with the majority of measured congeners being detected. The concentrations ranged from 0.087 µg/kg to 8.907 µg/kg whole weight (ww) for the sum of all measured PBDE congeners. PBBs occurred less frequently showing a corresponding range of <0.02 µg/kg to 0.97 µg/kg ww for the sum of seven PBB congeners. Concentrations vary depending on species and locations where landed, e.g. PBBs occurred more frequently and at higher levels in grey mullet from French waters. The high frequency of PBDE occurrence makes it prudent to continue the monitoring of these commonly consumed marine fish species. The web-based resource provides a flexible and efficient tool for assessors and policy-makers to monitor and evaluate levels within caught fish species improving evidenced-based decision processes.


Assuntos
Monitoramento Ambiental/métodos , Éteres Difenil Halogenados/análise , Bifenil Polibromatos/análise , Bifenilos Policlorados/análise , Alimentos Marinhos/análise , Animais , Peixes , Contaminação de Alimentos/análise , Noruega , Análise Espacial , Reino Unido
16.
Environ Entomol ; 46(3): 722-728, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28472267

RESUMO

Development and fecundity were investigated in an invasive alien thrips species, Frankliniella occidentalis (Pergande), and a related native species, Frankliniella intonsa (Trybom), under high CO2 concentration. Results show that the two thrips species reacted differently toward elevated CO2 concentration. Developmental duration decreased significantly (11.93%) in F. occidentalis at the CO2 concentration of 800 µl/liter; survival rate of all stages also significantly increased (e.g., survival rate of first instar increased 17.80%), adult longevity of both female and male extended (e.g., female increased 2.02 d on average), and both fecundity and daily eggs laid per female were higher at a CO2 concentration of 800 µl/liter than at 400 µl/liter. Developmental duration of F. intonsa decreased, insignificantly, at a CO2 concentration of 800 µl/liter. Unlike F. occidentalis, survival rate of F. intonsa declined considerably at higher CO2 concentration level (e.g., survival rate of first instar decreased 19.70%), adult longevity of both female and male curtailed (e.g., female reduced 3.82 d on average), and both fecundity and daily eggs laid per female were reduced to 24.86 and 0.83, respectively, indicating that there exist significant differences between the two CO2 levels. Results suggest that the population fitness of invasive thrips species might be enhanced with increase in CO2 concentration, and accordingly change the local thrips population composition with their invasion.


Assuntos
Dióxido de Carbono/metabolismo , Aptidão Genética , Tisanópteros/fisiologia , Animais , China , Comportamento Alimentar , Feminino , Fertilidade , Espécies Introduzidas , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Especificidade da Espécie , Tisanópteros/genética , Tisanópteros/crescimento & desenvolvimento
17.
Food Chem ; 226: 202-211, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28254013

RESUMO

Fourier transform infrared with attenuated total reflectance (FTIR-ATR) and Raman spectroscopy combined with partial least square regression (PLSR) were applied for the prediction of phenolic compounds and antioxidant activity in honey. Standards of catechin, syringic, vanillic, and chlorogenic acids were used for the identification and quantification of the individual phenolic compounds in six honey varieties using HPLC-DAD. Total antioxidant activity (TAC) and ferrous chelating capacity were measured spectrophotometrically. For the establishment of PLSR model, Raman spectra with Savitzky-Golay smoothing in wavenumber region 1500-400cm-1 was used while for FTIR-ATR the wavenumber regions of 1800-700 and 3000-2800cm-1 with multiplicative scattering correction (MSC) and Savitzky-Golay smoothing were used. The determination coefficients (R2) were ranged from 0.9272 to 0.9992 for Raman while from 0.9461 to 0.9988 for FTIT-ART. The FTIR-ATR and Raman demonstrated to be simple, rapid and nondestructive methods to quantify phenolic compounds and antioxidant activities in honey.


Assuntos
Mel/análise , Fenóis/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Sudão
18.
Biosens Bioelectron ; 81: 75-79, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-26921555

RESUMO

A simple and rapid bacteria counting method based on polyaniline (PANI)/bacteria thin film was proposed. Since the negative effects of immobilized bacteria on the deposition of PANI on glass carbon electrode (GCE), PANI/bacteria thin films containing decreased amount of PANI would be obtained when increasing the bacteria concentration. The prepared PANI/bacteria film was characterized with cyclic voltammetry (CV) technique to provide quantitative index for the determination of the bacteria count, and electrochemical impedance spectroscopy (EIS) was also performed to further investigate the difference in the PANI/bacteria films. Good linear relationship of the peak currents of the CVs and the log total count of bacteria (Bacillus subtilis) could be established using the equation Y=-30.413X+272.560 (R(2)=0.982) over the range of 5.3×10(4) to 5.3×10(8)CFUmL(-1), which also showed acceptable stability, reproducibility and switchable ability. The proposed method was feasible for simple and rapid counting of bacteria.


Assuntos
Compostos de Anilina/química , Bactérias/citologia , Carga Bacteriana/métodos , Técnicas Biossensoriais/métodos , Fenômenos Fisiológicos Bacterianos , Carbono/química , Espectroscopia Dielétrica , Eletrodos , Galvanoplastia/métodos , Reprodutibilidade dos Testes
19.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 34(5): 541-543, 2016 Oct 01.
Artigo em Chinês | MEDLINE | ID: mdl-28326719

RESUMO

Ectopic tooth is a common problem reported in clinics. Ectopic tooth generally occurs around its primary position, and long-distance displacement is rare. A case of ectopic maxillary premolar in palatal suture with a supernumerary tooth in the mentum region was reported in this study, and the relevant literature is presented in this paper.


Assuntos
Dente Pré-Molar , Dente Supranumerário , Queixo , Humanos , Má Oclusão , Suturas
20.
Biomed Microdevices ; 7(2): 131-5, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15940427

RESUMO

The Navier-Stokes equation was used to describe the characteristics of electro-osmotic flow. The corresponding numerical simulations were performed for varying zeta-potential and dimension. The results indicated that a step change in zeta-potential will cause a significant variation in the velocity profile and pressure distribution of the flow. A step change both in zeta-potential and dimension will result in a more violent variation near the joint of the capillary. This variation will reduce the separation efficiency and quality of capillary electrophoresis. The conclusions are helpful to design and fabrication of microfluidic devices, the analysis of data collected from such devices and improvement of the separation efficiency of capillary electrophoresis.


Assuntos
Eletroforese Capilar/métodos , Microfluídica/métodos , Modelos Teóricos , Ação Capilar , Simulação por Computador , Campos Eletromagnéticos , Movimento (Física) , Pressão Osmótica , Estresse Mecânico
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