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1.
J Agric Food Chem ; 68(10): 3171-3183, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32052628

RESUMO

Reversed-phase liquid chromatography with electrospray ionization-high-resolution/accuracy Fourier transform mass spectrometry (RPC-ESI-FTMS) and chemometrics were exploited to evaluate the influence of horizontal centrifugation by two- or three-phase decanters on the content of major phenolic secoiridoids in extravirgin olive oils (EVOOs). Despite the occurrence of other potential sources of variability typical of commercial olive oils, horizontal centrifugation was found to play a primary role, with a general increase of secoiridoid content occurring when two-phase decanters were used. As emphasized by principal component analysis (PCA), the increase involved preferentially oleacin and oleocanthal, when oxidative deterioration was purposely minimized during and/or after production, and oleuropein and ligstroside aglycones, when no vertical centrifugation was performed at the end of the productive cycle. The influence of the type of horizontal centrifugation was also emphasized by the elaboration of RPC-ESI-FTMS data based on hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA).


Assuntos
Centrifugação/métodos , Manipulação de Alimentos/métodos , Iridoides/química , Azeite de Oliva/química , Fenóis/química , Cromatografia de Fase Reversa , Frutas/química , Olea/química , Oxirredução , Espectrometria de Massas por Ionização por Electrospray
2.
mSphere ; 5(1)2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31996418

RESUMO

The vast majority of microbes inhabiting oligotrophic shallow subsurface soil environments have not been isolated or studied under controlled laboratory conditions. In part, the challenges associated with isolating shallow subsurface microbes may persist because microbes in deeper soils are adapted to low nutrient availability or quality. Here, we use high-throughput dilution-to-extinction culturing to isolate shallow subsurface microbes from a conifer forest in Arizona, USA. We hypothesized that the concentration of heterotrophic substrates in microbiological growth medium would affect which microbial taxa were culturable from these soils. To test this, we diluted cells extracted from soil into one of two custom-designed defined growth media that differed by 100-fold in the concentration of amino acids and organic carbon. Across the two media, we isolated a total of 133 pure cultures, all of which were classified as Actinobacteria or Alphaproteobacteria The substrate availability dictated which actinobacterial phylotypes were culturable but had no significant effect on the culturability of Alphaproteobacteria We isolated cultures that were representative of the most abundant phylotype in the soil microbial community (Bradyrhizobium spp.) and representatives of five of the top 10 most abundant Actinobacteria phylotypes, including Nocardioides spp., Mycobacterium spp., and several other phylogenetically divergent lineages. Flow cytometry of nucleic acid-stained cells showed that cultures isolated on low-substrate medium had significantly lower nucleic acid fluorescence than those isolated on high-substrate medium. These results show that dilution-to-extinction is an effective method to isolate abundant soil microbes and that the concentration of substrates in culture medium influences the culturability of specific microbial lineages.IMPORTANCE Isolating environmental microbes and studying their physiology under controlled conditions are essential aspects of understanding their ecology. Subsurface ecosystems are typically nutrient-poor environments that harbor diverse microbial communities-the majority of which are thus far uncultured. In this study, we use modified high-throughput cultivation methods to isolate subsurface soil microbes. We show that a component of whether a microbe is culturable from subsurface soils is the concentration of growth substrates in the culture medium. Our results offer new insight into technical approaches and growth medium design that can be used to access the uncultured diversity of soil microbes.


Assuntos
Actinobacteria/isolamento & purificação , Alphaproteobacteria/isolamento & purificação , Meios de Cultura/química , Microbiologia do Solo , Actinobacteria/crescimento & desenvolvimento , Alphaproteobacteria/crescimento & desenvolvimento , Arizona , Técnicas Bacteriológicas , Centrifugação , Florestas , Filogenia , RNA Ribossômico 16S/genética
3.
Chemosphere ; 238: 124600, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31446277

RESUMO

A high-gravity rotating packed bed (HiGee RPB) is very efficient at removing pollution because it exerts a strong high centrifugal and allows tiny droplets to form, which allows the control of gaseous and particulate air pollution. In this study, fine particles that are removed from integrated circuit (IC) chip carbonization process using a RPB are evaluated under different high gravity factors and liquid-to-gas ratios. The greatest number of particles captured per energy consumption is 17.77 mg kWh-1 in a RPB. This allow greater energy efficiency for the HiGee technology prevents an air-energy nexus. The maximum available particle removal efficiency for a RPB is determined using a response surface model (RSM). 99.5% of particles are removed at a high gravity factor of 262 and a liquid-to-gas ratio of 0.24. A semi-theoretical model is developed to determine the particle removal efficiency individually in packing and cavity zones of the RPB. More particles are removed in a cavity zone than in the packing zone as the high gravity factor increases. An empirical model shows that the particle removal efficiency depends on the operating factors. Finally, a comparison analysis of particulate matter treatment in various types of RPB is used to validate the performance in terms of particle removal using high-gravity technology for different industries.


Assuntos
Poluição Ambiental/análise , Recuperação e Remediação Ambiental/métodos , Material Particulado/análise , Carbono , Centrifugação/métodos , Gases , Tamanho da Partícula
4.
J Agric Food Chem ; 67(46): 12927-12935, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31657558

RESUMO

Emerging and fugitive contaminants (EFCs) released to our biosphere have caused a legacy and continuing threat to human and ecological health, contaminating air, water, and soil. Polluted media are closely linked to food security through plants, especially agricultural crops. However, measuring EFCs in plant tissues remains difficult, and high-throughput screening is a greater challenge. A novel rapid freeze-thaw/centrifugation extraction followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis was developed for high-throughput quantification of 11 EFCs with diverse chemical properties, including estriol, codeine, oxazepam, 2,4-dinitrotoluene, 1,3,5-trinitroperhydro-1,3,5-triazine, bisphenol A, triclosan, caffeine, carbamazepine, lincomycin, and DEET, in three representative crops, corn, tomato, and wheat. The internal aqueous solution, i.e., sap, is liberated via a freeze/thaw cycle, and separated from macromolecules utilizing molecular weight cutoff membrane centrifugal filtration. Detection limits ranged from 0.01 µg L-1 to 2.0 µg L-1. Recoveries of spiked analytes in three species ranged from 83.7% to 109%. Developed methods can rapidly screen EFCs in agriculture crops and can assess pollutant distribution at contaminated sites and gain insight on EFCs transport in plants to assess transmembrane migration in vascular organisms. The findings contribute significantly to environmental research, food security, and human health, as it assesses the first step of potential entry into the food chain, that being transmembrane migration and plant uptake, the primary barrier between polluted waters or soils and our food.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Poluentes Ambientais/química , Lycopersicon esculentum/química , Extratos Vegetais/química , Espectrometria de Massas em Tandem/métodos , Triticum/química , Zea mays/química , Centrifugação , Poluentes Ambientais/isolamento & purificação , Filtração , Contaminação de Alimentos/análise , Química Verde/métodos , Ensaios de Triagem em Larga Escala/métodos , Extratos Vegetais/isolamento & purificação
5.
Anal Sci ; 35(10): 1123-1127, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31597872

RESUMO

Measurement of single molecule interaction is performed by various micromanipulation techniques. However, a complex operation is required to perform the measurement, so the measurement throughput is low and a large amount of time is required for statistical analysis. In this paper, we propose a method for measuring intermolecular interactions that applies a tensile force to the intermolecular bond by using centrifugal force and can easily measure binding force. The binding force of an antigen-antibody reaction system was measured by the use of the proposed method as a proof of concept. The measured binding forces were distributed in the range of 19 - 133 pN. The values obtained by use of the proposed method were consistent with the conventional method. This result is promising for applications that require further development, such as the development of a biosensor as a novel measuring technique that is based on the intermolecular interaction measurement.


Assuntos
Centrifugação/instrumentação , Dispositivos Lab-On-A-Chip , Resistência à Tração , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Microscopia de Força Atômica , Microesferas , Poliestirenos/química
6.
J Agric Food Chem ; 67(44): 12237-12244, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31560847

RESUMO

Human milk oligosaccharides (HMOs) maintain and promote infant health. Most of the current methods for HMOs quantitation require labor-intensive and time-consuming steps for sample preparation. This study presents two very simple and easy-to-operate pretreatment methods, requiring either ultrafiltration or centrifugation to separate free oligosaccharides from whole fat human milk and other milk matrix before oligosaccharides labeling for quantifying HMOs using ultrahigh pressure liquid chromatography with fluorescence detection. A single chromatography run quantified 15 sialylated and neutral HMOs with high sensitivity (with an LOD less than 8 pg for all HMOs tested: about 1 pg for 2'-fucosyllactose, 3-fucosyllactose, 4'-galactosyllactose, 3'-galactosyllactose, and 6'-galactosyllactose) and good linearity with coefficient of correlation above 0.999. Accuracy and precision were satisfactory for both pretreatment methods. Overall, the centrifugation pretreatment was efficient and reliable for samples with high levels of oligosaccharides, and the ultrafiltration pretreatment was especially suitable for samples with low oligosaccharide abundance.


Assuntos
Centrifugação/métodos , Leite Humano/química , Oligossacarídeos/análise , Oligossacarídeos/isolamento & purificação , Ultrafiltração/métodos , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Humanos
7.
J Toxicol Sci ; 44(8): 515-521, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31378762

RESUMO

Currently, protocols for the dispersal of titanium dioxide (TiO2) nanoparticles are not standardized and often yield non-uniform particles and/or insufficient dispersal in liquid medium. Our study aimed to improve dispersal so that TiO2 nanoparticles are of uniform size, making nanotoxicity testing more reliable. Various combinations of vehicles, sonication durations, and sonication volumes were assessed for optimizing preparations of TiO2 nanoparticles. We tested each of five vehicles: ultrapure water (UPW), 0.2% disodium hydrogen phosphate (DSP), Dulbecco's phosphate-buffered saline (PBS), 0.9% saline (S), or S containing 0.05% Tween 80 (ST). We also assessed two sonication durations and three sonication volumes. Each suspension underwent ultrasonication and centrifugation; the supernatants were then analyzed. Particle size was measured by dynamic light scattering. P25 nanoparticles (~100 nm; the type of TiO2 nanoparticles used in our study) in UPW and 0.2% DSP were effectively dispersed; however, those in PBS, S, or ST were not. Relevant duration time and volume for sonication were examined with 0.2% DSP. A sonication time of 30 min and volume of 10 mL for each vial were determined to be optimal sonication conditions as determined with our dispersal assay. Under these optimal conditions, P25 nanoparticles sonicated/centrifuged in UPW or 0.2% DSP remained dispersed and exhibited long-term stability (90 days). We thus have developed a reliable procedure for preparing TiO2 nanoparticles in liquid-phase dispersions for toxicity testing.


Assuntos
Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Testes de Toxicidade/métodos , Centrifugação , Estabilidade de Medicamentos , Tamanho da Partícula , Fosfatos , Solução Salina , Sonicação , Água
8.
Plant Physiol Biochem ; 142: 482-489, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31437742

RESUMO

Knowledge of the characteristics of chemical components transported in the xylem sap of trunks remains deficient and limited because no appropriate method exists to extract the xylem sap from this part of the tree. We thus explored the differences in xylem sap components extracted by means of centrifugation and water displacement methods and depicted the level and behavior of chemical components in the xylem sap of trunks and branches of different aged trees from a pine forest in northern China. There were no significant differences between the two methods with respect to nitrogen (N) compounds and inorganic ions in the xylem sap. Potassium concentrations obtained by the methods were similar and consistent with the values obtained from earlier publications on woody species. This suggests that contamination of the xylem sap by the centrifugation method is negligible, and this method would be a reliable and robust tool for collection of the trunk xylem sap. Dissolved organic N was the dominant component of total N followed by nitrate (NO3-) and ammonium (NH4+). Potassium and chloride were the predominant cation and anion, respectively, of the xylem sap. The NO3- concentration basically did not change, whereas the NH4+ concentration was larger transported from the trunk to branches for the large tree class during foliage senescence. More inorganic N components (mainly NO3-) were found in young trees than in old trees. Our study contributes to improve the diagnostic assessments of tree physiological processes and growth in mature forest trees under environmental changes.


Assuntos
Centrifugação/métodos , Pinus/química , Caules de Planta/química , Xilema/química , Compostos de Amônio/análise , Cloretos/análise , Nitratos/análise , Nitrogênio/análise , Potássio/análise
9.
Enzyme Microb Technol ; 130: 109366, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31421726

RESUMO

This study investigates how sorbitol/methanol mixed induction affects fermentation performance, dewatering characteristics of cells during harvesting and the profile of host cell proteins (HCP) in the process fluid when producing the target recombinant protein aprotinin. Compared to standard methanol induction, sorbitol/methanol (1:1, C-mol/C-mol) mixed induction improved cellular viability from 92.8 ±â€¯0.3% to 97.7 ±â€¯0.1% although resulted in a reduced product yield from 1.65 ±â€¯0.03 g L-1 to 1.12 ±â€¯0.07 g L-1. On the other hand, average oxygen consumption rate (OUR) dropped from 241.4 ±â€¯21.3 mmol L-1 h-1 to 145.5 ±â€¯6.7 mmol L-1 h-1. Cell diameter decreased over time in the mixed induction, resulting in a D50 value of 3.14 µm at harvest compared to 3.85 µm with methanol. The reduction in cell size enhanced the maximum dewatering efficiency from 78.1 ±â€¯3.9% to 84.5 ±â€¯3.3% as evaluated by using an established ultra scale-down methodology that models pilot and industrial scale disc stack centrifugation. Seventy host cell proteins (HCPs) were identified in clarified supernatant when using sorbitol/methanol mixed induction regimen. The total number of HCPs identified with standard methanol induction was nearly one hundred. The downstream process advantage of the mixed induction lies in improved product purity by reducing both cell mortality and level of released whole cell proteins. This needs to be balanced and optimised against the observed reduction in product yield during fermentation.


Assuntos
Centrifugação , Metanol/metabolismo , Pichia/metabolismo , Sorbitol/metabolismo , Biomassa , Sobrevivência Celular , Fermentação , Oxigênio/metabolismo , Pichia/crescimento & desenvolvimento , Proteínas Recombinantes
10.
Food Microbiol ; 84: 103271, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421780

RESUMO

Fresh produce causes most foodborne outbreaks in the USA, and it is also considered a hazardous food product in other areas of the world such as Europe. The outbreaks attributed to fresh produce increase the focus of producers on hygiene to minimize exposure to food hazards. The fresh produce industry has the urgent need to detect if there are production lots contaminated with pathogenic microorganisms before distribution. Although the industry is mostly using end-product testing for the detection of target microorganisms, previous studies have evaluated the suitability of different sampling points within the production line of a fresh-cut processing plant. In the present study, the centrifuge effluent water was assessed as an alternative sampling point to end-product testing. E. coli was selected as an index microorganism of the presence of pathogens. The presence of E. coli was assessed in centrifuge effluent water, and fresh-cut lettuce from a commercial fresh-cut produce processing line (n = 95). The rate of false positives and negatives, as well as the specificity, sensitivity, and efficiency of the alternative method were calculated. The mean population of E. coli in positive water samples was 0.86 log cfu/100 mL, while the mean population of E. coli in positive fresh-cut lettuce samples was 0.23 log cfu/g. The proportion of positive samples in centrifuge effluent water and lettuce was similar (≈20%), and most of the results in both matrices were coincident (81.1%). However, the alternative method was not reliable due to its low sensitivity, as only 47.6% of the lettuce samples positive for E. coli could be matched with positive water samples.


Assuntos
Escherichia coli O157/isolamento & purificação , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Alface/microbiologia , Água/análise , Centrifugação , Contagem de Colônia Microbiana , Manipulação de Alimentos/métodos , Alimentos Crus/microbiologia
11.
Transfus Clin Biol ; 26(3): 164-170, 2019 Sep.
Artigo em Francês | MEDLINE | ID: mdl-31400933

RESUMO

BACKGROUND: The collection of granulocytes by apheresis requires volunteer donor stimulation by corticoids and the use of HES, a compound which is currently challenged by potential safety issues. Preparation of pooled granulocytes concentrates from whole blood buffy coats (PGC) represent an alternative to apheresis with a better benefit/risk for the donors. METHOD: Whole blood is collected in a bottom and top blood bag for buffy coat preparation. After centrifugation and separation, buffy coat are obtained. Twenty ABO matched buffy coats are selected for processing into one PGC. Four pools of five buffy coats were made, platelet additive solution is added to each pool, mixed gently and centrifuged. The red cell residue, supernatant and granulocyte rich layer are separated. Two granulocyte rich layers are pooled and added with 70mL of ABO matched plasma from the initial donations (=PGC10). The final PGC (=PGC20) is obtained by pooling two PGC10 into a platelet storage bag. Neutrophil content and in-vitro functionality are assessed at day of preparation (D1) and at expiry hour, 48 hours after collection (D2). RESULTS: On N=18, mean: Volume=408±4mL, 2.2*1010±0.24 neutrophils, Hematocrit=18%±3%, 4.7*1011platelets. Viability is well preserved: 95%±6% day of PGC preparation, 85%±7% after 24h of storage (D2). Functionality (ROS production measurement) is well preserved: 1.36±0.25 at D1 and 1.38±0.18 at D2. Expression and modulation of adhesion molecules after stimulation are normal at D1 and slightly decreased at D2 but still normal. CONCLUSIONS: PGC20 in vitro characteristics are in conformance with the EDQM guide (V19) and similar to apheresis for granulocytes content and hematocrit. The viability and two mean indicators which explore neutrophil function are well maintained during PGC preparation and after 24 hours of storage.


Assuntos
Buffy Coat/citologia , Separação Celular/métodos , Granulócitos , Sistema do Grupo Sanguíneo ABO/análise , Remoção de Componentes Sanguíneos , Doadores de Sangue , Plaquetas , Preservação de Sangue/instrumentação , Preservação de Sangue/métodos , Separação Celular/instrumentação , Centrifugação , Granulócitos/imunologia , Humanos , Masculino
12.
Anal Bioanal Chem ; 411(26): 6983-6994, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31463516

RESUMO

This study investigated the optimal inter-batch normalization method for gas chromatography/tandem mass spectrometry (GC/MS/MS)-based targeted metabolome analysis of rodent blood samples. The effect of centrifugal concentration on inter-batch variation was also investigated. Six serum samples prepared from a mouse and 2 quality control (QC) samples from pooled mouse serum were assigned to each batch, and the 3 batches were analyzed by GC/MS/MS at different days. The following inter-batch normalization methods were applied to metabolome data: QC-based methods with quadratic (QUAD)- or cubic spline (CS)-fitting, total signal intensity (TI)-based method, median signal intensity (MI)-based method, and isotope labeled internal standard (IS)-based method. We revealed that centrifugal concentration was a critical factor to cause inter-batch variation. Unexpectedly, neither the QC-based normalization methods nor the IS-based method was able to normalize inter-batch variation, though MI- or TI-based normalization methods were effective in normalizing inter-batch variation. For further validation, 6 disease model rat and 6 control rat plasma were evenly divided into 3 batches, and analyzed as different batches. Same as the results above, MI- or TI-based methods were able to normalize inter-batch variation. In particular, the data normalized by TI-based method showed similar metabolic profiles obtained from their intra-batch analysis. In conclusion, the TI-based normalization method is the most effective to normalize inter-batch variation for GC/MS/MS-based metabolome analysis. Graphical abstract.


Assuntos
Metaboloma , Metabolômica/métodos , Plasma/metabolismo , Soro/metabolismo , Animais , Centrifugação/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Masculino , Camundongos Endogâmicos ICR , Controle de Qualidade , Ratos , Síndrome da Serotonina/sangue , Síndrome da Serotonina/metabolismo , Espectrometria de Massas em Tandem/métodos
13.
Aerosp Med Hum Perform ; 90(9): 764-773, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31426891

RESUMO

INTRODUCTION: Physical conditioning may improve aircrew performance during exposure to high +Gz acceleration, although few studies have directly assessed this. The present study investigated the effects of a 12-wk Aircrew Conditioning Programme (ACP) on markers of G tolerance. The ACP comprises aerobic and muscle strengthening exercise performed twice weekly and targets improved fitness and reduced injury risk.METHODS: There were 36 UK Royal Air Force and Royal Navy aircrew who volunteered; 17 performed the ACP (Ex) and 19 acted as a control group (Con). Centrifuge testing was performed before and after the intervention. Relaxed G tolerance (RGT) and straining G tolerance (SGT), which had the addition of muscle tensing, were assessed. G endurance was also determined via repeated simulated air combat maneuvers (SACMs). During these centrifuge runs a number of physiological variables were recorded.RESULTS: During the G profile to determine RGT, neither RGT, HR, nor blood pressure responses were affected by the ACP. During SGT profiles, a lower HR at a given +Gz (+5.5 Gz) level following the ACP was observed (Ex: pre 146.0 ± 4.4, post 136.9 ± 5.6 bpm; Con: pre 148.0 ± 3.2, post 153.1 ± 3.3 bpm). BP was maintained and there was a tendency toward an improved SGT. The ACP increased the proportion of individuals completing the number of SACM profiles, although no meaningful differences were found between groups in other variables.CONCLUSION: Overall the ACP has no negative effect on RGT, reduced the physiological strain associated with a given level of +Gz (during SGT), and tended to improve the ability to tolerate repeated Gz exposure.Slungaard E, Pollock RD, Stevenson AT, Green NDC, Newham DJ, Harridge SDR. Aircrew conditioning programme impact on +Gz tolerance. Aerosp Med Hum Perform. 2019; 90(9):764-773.


Assuntos
Aceleração/efeitos adversos , Medicina Aeroespacial/métodos , Hipergravidade/efeitos adversos , Condicionamento Físico Humano/métodos , Adulto , Centrifugação , Humanos , Masculino , Militares , Reino Unido , Guerra , Adulto Jovem
14.
Analyst ; 144(19): 5766-5774, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31436781

RESUMO

We present a centrifugal microfluidic device which is combined with a solution-loading cartridge for fully automatic molecular diagnostics of foodborne pathogens. The proposed device could perform all processes of molecular diagnostics including bead-based DNA extraction, isothermal DNA amplification and colorimetric amplicon detection. In particular, the 3D-printed solution-loading cartridge was incorporated into the device to enhance the sample handling capacity and eliminate laborious steps such as pipetting for sample loading and sealing the top of the device. The cartridge could store four kinds of essential solutions (a sample solution, a washing solution, an elution solution, and a loop-mediated isothermal amplification (LAMP) cocktail) for pathogen detection, and the designated solutions were automatically released into the microdevice in a consecutive order by rotation. Since one unit of a device contains 20 reaction chambers, 18 kinds of pathogens plus two controls can be simultaneously detected in one test. As a proof-of-concept, we targeted four kinds of foodborne pathogens (Escherichia coli O157:H7, Salmonella typhimurium, Vibrio parahaemolyticus and Listeria monocytogenes) and successfully verified them, demonstrating that the centrifugal microdevice could be combined with a 3D printed solution-loading cartridge to achieve fully automated lab-on-a-chip-based molecular diagnostics. The entire process was completed in 65 min, and the limit of detection of the assay was 100 bacterial cells. The employment of the solution-loading cartridge successfully replaced the laborious and error-prone manual loading processes, which realized true automation of molecular diagnostics. This device could have promise in the fields of lab-on-a-chip and point-of-care molecular diagnostics.


Assuntos
DNA Bacteriano/análise , Doenças Transmitidas por Alimentos/microbiologia , Dispositivos Lab-On-A-Chip , Técnicas de Diagnóstico Molecular/métodos , Bactérias/genética , Bactérias/isolamento & purificação , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Centrifugação , Colorimetria , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/diagnóstico , Técnicas de Diagnóstico Molecular/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Impressão Tridimensional , Estudo de Prova de Conceito
15.
J Sci Food Agric ; 99(14): 6333-6341, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31268169

RESUMO

BACKGROUND: Wheat germ (WG) is a valuable by-product of the commercial milling industry and is used as a functional ingredient in various foods. Therefore, in this study, it is aimed to utilize defatted wheat germ (DWG) (1%, 3%, 5%, 10%) in chewing gum formulation, which is a different food matrix besides the conventional structures, and investigate the release kinetics of phenolics from DWG incorporated chewing gums with a new centrifugation method. RESULTS: According to the results, it was observed that DWG was a good source of total phenolics (2254.15 mg GAE kg-1 ). Based on the results obtained from texture profile and sensory analyses, DWG addition did not cause any reverse effect on the chewing gum texture. Centrifugation method was used to indirectly simulate the physical effects of the chewing process. In particular, after 5 min of chewing and centrifugation, phenolic release levels were 59.07% and 59.41%, respectively. The model used in the previous studies showed a better correlation than Korsmeyer-Peppas model for ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid), CUPRAC (cupric ion reducing antioxidant capacity), and DPPH (2,2-diphenyl-1-picrylhydrazyl) assay results. CONCLUSION: The results showed that phenolics release from gum base polymer matrix might be dominated by erosion of matrix due to chewing action. Similar phenolic release kinetics were obtained by centrifugation and chewing methods. Therefore, centrifuge equipment can be used to simulate the chewing forces acting on the gum when optimization is performed. © 2019 Society of Chemical Industry.


Assuntos
Goma de Mascar/análise , Fenóis/química , Extratos Vegetais/química , Triticum/química , Antioxidantes/química , Centrifugação , Cinética , Sementes/química
16.
Biomed Microdevices ; 21(3): 67, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273556

RESUMO

This paper demonstrates the fabrication of a compartmentalized microfluidic device with docking sites to position a single neuron or a cluster of 5-6 neurons along with varying length of microgrooves and the optimization process for culturing primary mammalian neurons at low densities. The principle of centrifugation was employed to situate cells in desired locations followed by the application of a fluid flow to remove the extra or unwanted cells lying in the vicinity of the located neurons. The neuronal cell density was optimized by seeding 103 cells and 104 cells/microfluidic device. The speed of centrifugation was optimized as 1500 rpm for 1 min and a cell density of greater than or equal to 104 cells/microfluidic device was found to be suitable for loading maximum number of docking sites. The outcomes of the simulated experiments was found to be in compliance with the experimemtal verifications. Furthermore, the cells cultured within the microfluidic device were assessed for immunocytochemical staining and the axonal growth was quantified with the help of an Axofluidic software. Although, several in vitro microfluidic platforms have been developed that facilitate the investigations where communication between neurons or between neurons and other cell types is concerned, none of the partitioned devices so far has reported the presence of docking sites along with an array of grooves of varying lengths. These physically connected but fluidically isolated compartmentalized microfluidic devices may serve us in analysing the activity of a low density of neurons and the influence of axonal length in setting up a communication with other cell type.This platform is useful to gain insights into the processes of synapse formation, axonal guidance, cell-cell interaction, to name a few.


Assuntos
Técnicas de Cultura de Células/instrumentação , Dispositivos Lab-On-A-Chip , Neurônios/citologia , Animais , Axônios/metabolismo , Contagem de Células , Centrifugação , Ratos
17.
Hematology ; 24(1): 533-537, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31280705

RESUMO

OBJECTIVE: Buffy coat and ficoll of bone marrow (BM) are viable options for the study of minimal residual disease (MRD) in multiple myeloma (MM). As yet, there is no data about the superiority of either sample types. Herein, we aimed to address this issue. METHODS: Forty pairs of ficolled BMs and BM buffy coats of 19 MM patients were studied for MRD by allele-specific oligonucleotide real-time quantitative PCR, with patient-specific primers/probes whenever appropriate. RESULTS: There were 41 pairs of MRD data for comparison analysis due to one patient with biclonal disease. MRD levels in ficolls and buffy coats were highly concordant (rs = 0.936, P < 0.0001), with 31 (76%) and seven (17%) pairs being concomitantly MRD-positive or -negative. On the other hand, apart from the 16 pairs being both MRD-negative, or -positive but not quantifiable in ficolls and buffy coats, majority (n = 22, 88%) had higher MRD levels in ficolled BMs than BM buffy coats. Furthermore, in 17 pairs, in which MRD was quantifiable in both, MRD levels in ficolled BMs were 3.1 times those of BM buffy coats (median, 567/105 vs. 184/105, P = 0.001). CONCLUSION: Taken together, ficolled BM is more sensitive than BM buffy coat for MRD detection in MM, hence should be recommended.


Assuntos
Exame de Medula Óssea/métodos , Separação Celular/métodos , Centrifugação/métodos , Ficoll , Mieloma Múltiplo/patologia , Centrifugação com Gradiente de Concentração/métodos , Células Clonais , Primers do DNA , DNA de Neoplasias/análise , DNA de Neoplasias/isolamento & purificação , Rearranjo Gênico , Genes de Imunoglobulinas , Humanos , Leucócitos Mononucleares , Mieloma Múltiplo/genética , Neoplasia Residual , Células-Tronco Neoplásicas , Plasmócitos , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Manejo de Espécimes
18.
Rev Soc Bras Med Trop ; 52: e20180505, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31271620

RESUMO

INTRODUCTION: The microscopic examination of microhematocrit tubes (mHCT) has been proposed as the gold standard for acute and congenital Chagas disease diagnosis. We compared different mHCT methodologies detecting T. cruzi parasites in the blood. METHODS: The rotating method, water mount, and immersion oil methods were compared for their suitability, sensitivity, and specificity. RESULTS: The rotating method was easier, faster, and more sensitive than the others with 100% specificity. CONCLUSIONS: The rotating method is feasible for laboratory technicians with standard training in microscopic techniques and is recommended for the diagnosis of acute Chagas disease in primary health care facilities.


Assuntos
Tubo Capilar , Centrifugação/métodos , Doença de Chagas/diagnóstico , Hematócrito/métodos , Parasitemia/diagnóstico , Trypanosoma cruzi/isolamento & purificação , Animais , Doença de Chagas/sangue , Doença de Chagas/parasitologia , Serviços de Laboratório Clínico , Humanos , Parasitemia/parasitologia , Sensibilidade e Especificidade
19.
J Chromatogr A ; 1605: 460362, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31320134

RESUMO

Sesquiterpene lactones (SL) are commonly found in Asteraceae and present a promising anti-inflammatory activity. Previously described in Lepidaploa genus, glaucolide B has never been investigated for its anti-inflammatory potential. This study aimed to establish an efficient process for the extraction of glaucolide B (1) from Lepidaploa chamissonis leaves and to develop a simple and fast method for its purification by using centrifugal partition chromatography (CPC), as well as to investigate in vitro the anti-inflammatory effects of glaucolide B. Thus, an optimized washing extractive process performed on L. chamissonis leaves allowed to obtain a SL enriched extract (4.11 g). After a successful defatting pretreatment of the crude extract, the glaucolide B enriched ethyl acetate portion (2.00 g) was fractionated by CPC affording, in a single-step isolation, compound 1 (1.04 g) in great yield (25%) and purity (97%). Cytotoxicity effect of 1 on RAW 264.7 macrophages was determined by using MTT assay, revealing a CC10 of 14.11 µM. Compound 1 at 1, 3 and 10 µM inhibited the nitrite/nitrate (NOx) metabolites production and the pro-inflammatory interleukin 6 (IL-6) secretion on lipopolysaccharide-stimulated RAW 264.7 cells. The extractive process used turned to be selective for SL and CPC technique proved a simple and effective tool for the isolation of 1 within few hours. Isolated for the first time from L. chamissonis leaves, glaucolide B presented a significant inhibitory effect on both NO and IL-6 secretion under non-toxic concentrations.


Assuntos
Anti-Inflamatórios/isolamento & purificação , Asteraceae/química , Centrifugação/métodos , Cromatografia Líquida/métodos , Sesquiterpenos/isolamento & purificação , Animais , Anti-Inflamatórios/farmacologia , Morte Celular/efeitos dos fármacos , Interleucina-6/biossíntese , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Óxido Nítrico/biossíntese , Extratos Vegetais/química , Folhas de Planta/química , Células RAW 264.7 , Sesquiterpenos/farmacologia
20.
Artif Organs ; 43(9): 849-859, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31321785

RESUMO

Mechanical circulatory support devices have been used clinically for patients with heart failure for over 10 years. However, thrombus formation inside blood pumps remains a risk to patient life, causing pump failure and contributing to neurological damage through embolization. In this article, we propose a method for preventing thrombus formation by applying vibrational excitation to the impeller. We evaluate the ability of this method to enhance the antithrombogenic properties of a magnetically levitated centrifugal blood pump and ensure that the impeller vibration does not cause undue hemolysis. First, 3 vibrational conditions were compared using an isolated pump without a mock circulation loop; the vibrational excitation frequencies and amplitudes for the impeller were set to (a) 0 Hz-0 µm, (b) 70 Hz-10 µm, and (c) 300 Hz-2.5 µm. The motor torque was measured to detect thrombus formation and obtain blood coagulation time by calculating the derivative of the torque. Upon thrombus detection, the pump was stopped and thrombi size were evaluated. The results showed an increase in the blood coagulation time and a decrease in the rate of thrombus formation in pumps with the impeller vibration. Second, an in vitro hemolysis test was performed for each vibrational condition to determine the effect of impeller vibration on hemolysis. The results revealed that there was no significant difference in hemolysis levels between each condition. Finally, the selected vibration based on the above test results and the non-vibration as control were compared to investigate antithrombogenic properties under the continuous flow condition. The blood coagulation time and thrombi size were investigated. As a result, vibrational excitation of the impeller at a frequency of 300 Hz and amplitude of 2.5 µm was found to significantly lengthen clotting time, decreasing the rate of pump thrombus compared to the non-vibration condition. We indicate the potential of impeller vibration as a novel mechanical antithrombogenic mechanism for rotary blood pumps.


Assuntos
Circulação Assistida/instrumentação , Coração Auxiliar/efeitos adversos , Trombose/etiologia , Animais , Circulação Assistida/efeitos adversos , Coagulação Sanguínea , Centrifugação/efeitos adversos , Centrifugação/instrumentação , Desenho de Equipamento , Hemólise , Humanos , Magnetismo/instrumentação , Suínos , Trombose/sangue , Trombose/prevenção & controle , Vibração
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