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1.
Int J Nanomedicine ; 15: 2303-2314, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32280222

RESUMO

Objective: The objective of this study is to evaluate the performance and feasibility of surface-enhanced Raman spectroscopy coupled with a filter membrane and advanced multivariate data analysis on identifying and differentiating benign and malignant thyroid tumors from blood plasma. Patients and Methods: We proposed a membrane filter SERS technology for the differentiation between benign thyroid tumor and thyroid cancer. That is to say, by using filter membranes with optimal pore size, the blood plasma samples from thyroid tumor patients were pretreated with the macromolecular proteins being filtered out prior to SERS measurement. The SERS spectra of blood plasma ultrafiltrate obtained using filter membranes from 102 patients with thyroid tumors (70 thyroid cancers and 32 benign thyroid tumors) were then analyzed and compared. Two multivariate statistical analyses, principal component analysis-linear discriminate analysis (PCA-LDA) and Lasso-partial least squares-discriminant analysis (Lasso-PLS-DA), were performed on the SERS spectral data after background subtraction and normalization, as well as the first derivative processing, to analyze and compare the differential diagnosis of benign thyroid tumors and thyroid cancer. Results: SERS measurements were performed in blood plasma acquired from a total of 102 thyroid tumor patients (benign thyroid tumor N=32; thyroid cancer N=70). By using filter membranes, the macromolecular proteins in blood plasma were effectively filtered out to yield high-quality SERS spectra. 84.3% discrimination accuracy between benign and malignant thyroid tumor was achieved using PCA-LDA method, while Lasso-PLS-DA yields a discrimination accuracy of 90.2%. Conclusion: Our results demonstrate that SERS spectroscopy, coupled with ultrafiltration and multivariate analysis has the potential of providing a non-invasive, rapid, and objective detection and differentiation of benign and malignant thyroid tumors.


Assuntos
Plasma/química , Análise Espectral Raman/métodos , Neoplasias da Glândula Tireoide/sangue , Ultrafiltração/métodos , Adulto , Diagnóstico Diferencial , Análise Discriminante , Humanos , Membranas Artificiais , Nanopartículas Metálicas/química , Pessoa de Meia-Idade , Análise Multivariada , Análise de Componente Principal , Estudo de Prova de Conceito , Prata/química , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/patologia , Ultrafiltração/instrumentação
2.
Anal Bioanal Chem ; 412(9): 2123-2136, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32072210

RESUMO

Ultrafiltration/diafiltration (UF/DF) plays an important role in the manufacturing of biopharmaceuticals. Monitoring critical process parameters and quality attributes by process analytical technology (PAT) during those steps can facilitate process development and assure consistent quality in production processes. In this study, a lab-scale cross-flow filtration (CFF) device was equipped with a variable pathlength (VP) ultraviolet and visible (UV/Vis) spectrometer, a light scattering photometer, and a liquid density sensor (microLDS). Based on the measured signals, the protein concentration, buffer exchange, apparent molecular weight, and hydrodynamic radius were monitored. The setup was tested in three case studies. First, lysozyme was used in an UF/DF run to show the comparability of on-line and off-line measurements. The corresponding correlation coefficients exceeded 0.97. Next, urea-induced changes in protein size of glucose oxidase (GOx) were monitored during two DF steps. Here, correlation coefficients were ≥ 0.92 for static light scattering (SLS) and dynamic light scattering (DLS). The correlation coefficient for the protein concentration was 0.82, possibly due to time-dependent protein precipitation. Finally, a case study was conducted with a monoclonal antibody (mAb) to show the full potential of this setup. Again, off-line and on-line measurements were in good agreement with all correlation coefficients exceeding 0.92. The protein concentration could be monitored in-line in a large range from 3 to 120 g L- 1. A buffer-dependent increase in apparent molecular weight of the mAb was observed during DF, providing interesting supplemental information for process development and stability assessment. In summary, the developed setup provides a powerful testing system for evaluating different UF/DF processes and may be a good starting point to develop process control strategies. Graphical Abstract Piping and instrumentation diagram of the experimental setup and data generated by the different sensors. A VP UV/Vis spectrometer (FlowVPE, yellow) measures the protein concentration. From the data of the light scattering photometer (Zetasizer, green) in the on-line measurement loop, the apparant molecular weight and z-average are calculated. The density sensor (microLDS) measures density and viscosity of the fluid in the on-line loop.


Assuntos
Proteínas/análise , Tecnologia Farmacêutica/instrumentação , Animais , Anticorpos Monoclonais/análise , Tampões (Química) , Difusão Dinâmica da Luz , Desenho de Equipamento , Glucose Oxidase/análise , Humanos , Muramidase/análise , Tamanho da Partícula , Espectrofotometria Ultravioleta , Ultrafiltração/instrumentação
3.
Food Chem ; 313: 126154, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31931425

RESUMO

The aim of this study was to develop a scalable crossflow diafiltration/ultrafiltration procedure for quinoa 11S globulin purification starting at the bench scale using Ultra15 centrifugal filter devices. The electrophoretic profiles of centrifugal ultrafiltration fractions showed a high heterogeneity in the bands, while crossflow ultrafiltration reduced the phenomena of protein sticking to the membrane, avoiding aggregate formation. In the crossflow protein concentration, flux decline curves were studied according to Hermia's fouling mechanisms and the resistance in a series model. High reversible resistance was related to external mechanisms due to complete blockage of the membrane surface followed by cake formation. The crossflow ultrafiltration was the most efficient technique for obtaining 57 kDa chenopodin isolate with higher processing capacity, purity and protein yield. The diafiltration/ultrafiltration process proved to be adequate and easy to handle to scale up the production of the 11S quinoa globulin.


Assuntos
Proteínas de Plantas/isolamento & purificação , Ultrafiltração/métodos , Centrifugação/métodos , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Ultrafiltração/instrumentação
4.
Methods Mol Biol ; 2052: 23-41, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31452155

RESUMO

The procedure described here provides instructions for detection of Cryptosporidium recovered from large-volume water samples. Water samples are collected by dead-end ultrafiltration in the field and ultrafilters are processed in a laboratory. Microbes recovered from the filters are further concentrated and subjected to Cryptosporidium isolation or nucleic acid extraction methods for the detection of Cryptosporidium oocysts or Cryptosporidium DNA.


Assuntos
Cryptosporidium/isolamento & purificação , Microscopia de Fluorescência/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Ultrafiltração/métodos , Água/parasitologia , Cryptosporidium/genética , DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Imunofluorescência/métodos , Microscopia de Fluorescência/instrumentação , Oocistos/imunologia , Ultrafiltração/instrumentação , Fluxo de Trabalho
5.
Environ Geochem Health ; 42(3): 809-818, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30993498

RESUMO

Seasonal algal bloom, a water supply issue worldwide, can be efficiently solved by membrane technology. However, membranes typically suffer from serious fouling, which hinders the wide application of this technology. In this study, the feasibility of adding Ca2+ to control membrane fouling in coagulation-membrane treatment of algal-rich water was investigated. According to the results obtained, the normalized membrane flux decreased by a lower extent upon increasing the concentration of Ca2+ from 0 to 10 mmol/L. Simultaneously, the floc particle size increased significantly with the concentration of Ca2+, which leads to a lower hydraulic resistance. The coagulation performance is also enhanced with the concentration of Ca2+, inducing a slight osmotic pressure-induced resistance. The formation of Ca2+ coagulation flocs resulted in a looser, thin, and permeable cake layer on the membrane surface. This cake layer rejected organic pollutants and could be easily removed by physical and chemical cleaning treatments, as revealed by scanning electron microscopy images. The hydraulic irreversible membrane resistance was significantly reduced upon addition of Ca2+. All these findings suggest that the addition of Ca2+ may provide a simple-operation, cost-effective, and environmentally friendly technology for controlling membrane fouling during coagulation-membrane process for algal-rich water treatment.


Assuntos
Cálcio/química , Eutrofização , Ultrafiltração/instrumentação , Purificação da Água/instrumentação , Purificação da Água/métodos , Membranas Artificiais , Microcystis/química , Microscopia Eletrônica de Varredura , Pressão Osmótica , Tamanho da Partícula , Ultrafiltração/métodos , Poluentes Químicos da Água/química
6.
Chemosphere ; 238: 124659, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524612

RESUMO

A hybrid system was developed in this study consisting of different coagulation systems and ultrafiltration (UF). Property and effect of flocs formed in different coagulation systems on ultrafiltration membrane fouling control were investigated. All three coagulation systems, as pretreatment of UF, were effective in improving membrane flux and reducing membrane resistance within an appropriate range of natural organic matters (NOM) concentration. At high initial NOM concentration, the performance of polyaluminum chloride (PAC) on NOM removal and fouling control was severely limited. For PAC-poly dimethyl diallyl ammonium chloride (PAC-PolyDMDAAC) coagulation system, the limitation of initial NOM concentration on removing NOM and alleviating membrane fouling was slightly weakened, indicating composite flocculant PAC-PolyDMDAAC produced larger flocs through combined action of charge neutralization and adsorption bridging. In PAC + PolyDMDAAC dual coagulation system, the combined action of adsorption-bridging effect, sweeping effect, and charge neutralization were the mechanisms under both low and high initial NOM concentration. Although the flocs formed in PAC + PolyDMDAAC dual coagulation system had poor recovery ability compared with those formed in PAC and PAC-PolyDMDAAC coagulation system, flocs formed through adsorption-bridging and sweeping had large size and higher ability to resist shear force, resulting in the formation of cake layer with porous and fluffy structure and less blockage in membrane pore in PAC + PolyDMDAAC dual coagulation system. These results demonstrated that dual coagulation system combined PAC coagulation and PolyDMDAAC flocculation as a pretreatment of UF process can improve the characteristics of flocs and structure of cake layer for improving NOM removal and controlling membrane fouling.


Assuntos
Hidróxido de Alumínio , Membranas Artificiais , Ultrafiltração/métodos , Adsorção , Floculação , Ultrafiltração/instrumentação , Purificação da Água/métodos
7.
J Dairy Sci ; 103(1): 201-209, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31677839

RESUMO

Concentrating milk by reverse osmosis (RO) has the potential to increase cheese yield but is known to impair cheese-making properties. The main compositional differences between ultrafiltration (UF) and RO concentrates are the high lactose and mineral contents of the latter. The objective of this work was to determine the distinct effects of high lactose and high minerals on the cheese-making properties of RO concentrate, by supplementing UF concentrate with lactose. The soluble colloidal equilibria of concentrates were studied as well as several other properties: rennet gelation behavior, cheese mass balance, composition, and microstructure. Rennet coagulation time was longer and gel firming rate was lower for RO concentrate than for UF concentrate. Lactose was mainly responsible for these differences. Lactose in RO concentrate was also responsible for the 7% increase of moisture-adjusted cheese yield, relative to UF concentrate. Compared with cheese made from UF concentrate, cheese made from RO concentrate showed higher moisture content, which could not be attributed to lactose but to the high mineral concentration. This study showed the potential of using RO instead of UF concentrate to maximize cheese yield. The approach is, however, limited to applications where post-acidification can be controlled, and will require appropriate strategies to reduce the negative effects of high mineral content in RO concentrate.


Assuntos
Queijo/análise , Manipulação de Alimentos/instrumentação , Lactose/análise , Minerais/análise , Osmose , Ultrafiltração/instrumentação
8.
Environ Sci Pollut Res Int ; 26(36): 36296-36307, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31713819

RESUMO

Cake formed by flocs is a crucial factor to affect membrane fouling during coagulation-ultrafiltration process. To investigate the role of floc properties on cake, cake characteristics under various coagulant dosage conditions were calculated by scanning electron microscope (SEM) imaging. Results found that one SEM image with × 5000 magnification could accurately estimate cake porosity with relative error lower than 5.00% for all conditions, whereas more SEM images with × 10,000 magnification or × 20,000 magnification should be applied to calculate cake porosity precisely. This could be explained by different pore information of SEM images with various magnifications. Compared to single SEM image with × 10,000 magnification and × 20,000 magnification, single SEM image with × 5000 magnification contained the most comprehensive pore information and slightly overestimated pore area for pore smaller than 0.4 µm2 due to lower resolution. To verify feasibility by SEM image evaluating cake characteristics, cake porosity calculated by SEM image and Carman-Kozeny equation were analyzed. The results showed that cake porosity estimated by these two methods were nearly the same, proving the feasibility of this method. Moreover, with the increase of coagulant dosage, cake porosity presented similar variation with floc average size, indicating that floc average size was likely to dominate cake porosity in this study. For pore characteristics, pore average characteristic length and pore average area were in accordance with floc fractal dimension, whereas pore fractal dimension and pore amount were consistent with floc average size. This gives specific information about the relation between floc properties and cake characteristics.


Assuntos
Floculação , Microscopia Eletrônica de Varredura , Ultrafiltração/métodos , Incrustação Biológica/prevenção & controle , Coagulantes/análise , Fractais , Membranas Artificiais , Porosidade , Ultrafiltração/instrumentação
9.
Environ Int ; 133(Pt B): 105202, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31678903

RESUMO

Phenolic moieties are important constituents in dissolved organic matter (DOM) in natural and engineered systems. However, their roles in membrane fouling mechanism during drinking water treatment by ultrafiltration (UF) have remained elusive. Herein, by using water insoluble polyvinylpolypyrrolidone (PVPP) resins, we sequestered the phenolic moieties from a model DOM (Suwannee River DOM, SRDOM) and characterized their molecular profiles using electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). Subsequently, their roles in UF membrane fouling propensity were investigated using reconstituted DOM solutions with various concentrations of phenolic moieties. The results showed that the phenolic moieties were of higher molecular weight and rich in unsaturation cyclic structures and oxygen-rich groups. Van Krevelen diagrams revealed that the sequestered sample was rich in aromatics structures and tannins-like compounds while contained less alicyclic organic acids in comparison with the original SRDOM, which was consistent with the aromaticity index (AI) analysis. UF experiments showed that the more phenolic moieties in DOM solution, the severer decline of flux was observed. The phenolic moieties played a significant role in membrane irremovable fouling due to the hydrophobic interactions and their higher molecular weight as evidenced by membrane cleaning tests. By surface characterization, the SRDOM fouled membrane was identified to have a higher water contact angle value and abundant C-O groups, likely due to the adsorption of more hydrophobic phenolic moieties. Overall, these findings highlighted links between phenolic moieties and membrane fouling development, and implied that membrane performance could be improved by pre-removal of phenolic moieties in DOM.


Assuntos
Membranas Artificiais , Fenóis/química , Povidona/análogos & derivados , Ultrafiltração/instrumentação , Poluentes Químicos da Água/química , Purificação da Água/instrumentação , Adsorção , Espectrometria de Massas , Povidona/química , Rios
10.
Chemosphere ; 237: 124859, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549667

RESUMO

Concentration polarization is an important issue in micellar enhanced ultrafiltration (MEUF) of wastewater containing heavy metal ions at low surfactant concentrations. In this paper, we studied removal of Cd(Ⅱ) by cross flow MEUF at low sodium dodecyl sulfate (SDS) concentration levels, and the role of concentration polarization in flux decline and Cd(Ⅱ) rejection was emphasized. Concentration polarization resistance and SDS concentration near membrane were calculated to characterize concentration polarization. The results showed that SDS concentration near membrane was 13 mM when feed concentration was merely 0.8 mM. By combining phase diagram of SDS, structures of SDS micelles in concentration polarization layer were deduced and thin layer structure transformed to porous structure formed by accumulated globular micelles when SDS concentration increased. Although micelles formed in concentration polarization layer was responsible for flux decline, they also provided adsorption sites for Cd(Ⅱ).


Assuntos
Cádmio/isolamento & purificação , Ultrafiltração/métodos , Águas Residuárias/química , Adsorção , Membranas Artificiais , Metais Pesados , Micelas , Dodecilsulfato de Sódio/química , Tensoativos/química , Ultrafiltração/instrumentação
11.
Chemosphere ; 235: 58-69, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31255766

RESUMO

In this study, ultrafiltration membrane fouling was alleviated by hydrophilic modification and coagulation pretreatment. A polydopamine (PDA) layer was used as a bridge to introduce the nano titanium dioxide (TiO2) onto the polysulfone (PSf) membranes, forming a hydrophilic modified layer. A relationship model was established between the coagulation efficiencies and floc properties and membrane fouling of the modified PSf membranes during the coagulation/ultrafiltration (C-UF) process. The combination styles of flocculants, poly dimethyldiallylammonium chloride (PDMDAAC) and polyaluminum chloride (PAC) were used in C-UF hybrid process. The characterization results indicated that the hydrophilicity was significantly enhanced in the modified PSf membranes. Scanning electron microscopy (SEM) tests proved that the PDA layer could be tightly bound to TiO2 by coordination bond onto PSf membrane surface. In the acidic conditions, more TiO2 nano-particles were adhered on the PDA particles surface as the pH of (NH4)2TiF6 solution was increased, which resulted in higher hydrophilicity of membranes. In addition, the C-UF tests exhibited that the coagulation efficiency was greatly improved in the PAC/PDMDAAC system, and the PSf membrane modified by PDA/TiO2 in UF tests significantly reduced the membrane fouling, this was partially due to the formation of TiO2 modified coating with higher hydrophilicity.


Assuntos
Incrustação Biológica/prevenção & controle , Membranas Artificiais , Ultrafiltração/métodos , Hidróxido de Alumínio , Floculação , Interações Hidrofóbicas e Hidrofílicas , Indóis , Polímeros , Sulfonas , Titânio , Ultrafiltração/instrumentação , Purificação da Água/instrumentação , Purificação da Água/métodos
12.
Environ Int ; 130: 104869, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31228783

RESUMO

BACKGROUND: Increasing attention is being paid to the treatment of shale gas fracturing wastewater, including flowback and produced water (FPW). Energy-efficient pretreatment technologies suitable for desalinating and reusing FPW are of paramount importance. OBJECTIVES: This work focused on enhanced fouling alleviation of ultrafiltration (UF) as a pretreatment for desalinating shale gas FPW in Sichuan Basin, China. The UF fouling behaviors under various backwash water sources or coagulant dosages were evaluated, and membrane surface characteristics were correlated with UF fouling. The feasibility of Fourier transform infrared (FTIR) microscope mapping technique in quantifying UF fouling was also assessed. METHODS: Various backwash water sources, including UF permeate, ultrapure water, nanofiltration (NF) permeate, reverse osmosis (RO) permeate, RO concentrate and forward osmosis (FO) draw solution, were used to clean UF membranes fouled by shale gas FPW. The UF fouling behaviors were characterized by total and non-backwashable fouling rates. Membrane surface characteristics were analyzed by scanning electron microscopy (SEM), total tension surface and FTIR spectra. RESULTS: Protein-like substances in terms of fluorescence intensity in the backwash water decreased with the order of UF permeate, RO concentrate, NF permeate, RO permeate and FO draw solution. Compared with UF permeate backwashing, alleviated UF fouling was observed by using demineralized backwash water including ultrapure water and RO permeate, irrespective of hollow fiber and flat-sheet membranes. NF permeate and RO concentrate after NF used as backwash water resulted in low and comparable membrane fouling with that in integrated coagulation-UF process under optimal dosage. Among the backwash water tested, FO draw solution backwashing corresponded to the lowest UF fouling rates, which were even lower than that in the presence of coagulant under optimal dosage. The superiority of these backwash water sources to UF permeate was further confirmed by SEM images and FTIR spectra. The residual foulant mass on membrane surface and the total surface tension correlated well with non-backwashable and total fouling rates, respectively. CONCLUSIONS: FTIR microscopy was a powerful surface mapping technique to characterize UF membrane fouling caused by shale gas FPW. Backwash water sources significantly influenced the fouling of UF membranes. In the integrated UF-NF-RO or UF-FO process, RO concentrate or FO draw solution were proposed as backwash water to enhance UF fouling control and decrease waste discharge simultaneously.


Assuntos
Resíduos Industriais , Membranas Artificiais , Gás Natural , Ultrafiltração/instrumentação , Águas Residuárias , Purificação da Água/instrumentação , Osmose , Salinidade , Purificação da Água/métodos
13.
Biomed Res Int ; 2019: 5276841, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31080821

RESUMO

Magnetic carbon nanocomposite (MCN) was synthesized from waste biomass precursor, pineapple. The prepared adsorbent was characterized using different instrumental techniques and was used to remove levofloxacin (LEV) from effluents. The maximum sorption of LEV was observed at pH 7. Pseudo-2nd-order (PSO) kinetic was found to be the best model that fits well the adsorption kinetics data. For Langmuir adsorption isotherm, the R2 value was higher as compared with other isotherms. The Van't Hoff equation was used for thermodynamic parameters determinations. ΔS° (standard entropy) was positive and ΔG° (standard Gibb's free energy) was negative: -0.37, -1.81, and -3.73 kJmol-1 corresponding to 25, 40, and 60°C. The negative values of ΔG° at different temperatures stipulate that the adsorption of LEV was spontaneous in nature and adsorbent has a considerable affinity for LEV molecules. The MCN was then utilized in hybrid way by connecting with ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) membranes in series and as a result enhanced permeate fluxes were observed. The percent retention of LEV molecules was lower with UF membrane and with NF it was 96%, while it was 100% with RO. For MCN/UF and MCN/NF systems, improvement in % retention was recorded.


Assuntos
Filtração/métodos , Levofloxacino/isolamento & purificação , Magnetismo/métodos , Nanocompostos/química , Adsorção , Carbono/química , Filtração/instrumentação , Concentração de Íons de Hidrogênio , Resíduos Industriais , Cinética , Levofloxacino/química , Membranas Artificiais , Peso Molecular , Termodinâmica , Ultrafiltração/instrumentação , Ultrafiltração/métodos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química
14.
Biotechnol J ; 14(8): e1800570, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31106962

RESUMO

Currently, marketed influenza vaccines are only efficient against homologous viruses, thus requiring a seasonal update based on circulating subtypes. This constant reformulation adds several challenges to manufacturing, particularly in purification due to the variation of the physicochemical properties of the vaccine product. A universal platform approach capable of handling such variation is therefore of utmost importance. In this work, a filtration-based approach is explored to purify influenza virus-like particles. Switching from adsorptive separation to size-based purification allows overcoming the differences in retention observed for different influenza strains. The proposed process employs a cascade of ultrafiltration and diafiltration steps, followed by a sterile filtration step. Different process parameters are assessed in terms of product recovery and impurities' removal. Membrane chemistry, pore size, operation modes, critical flux, transmembrane pressure, and permeate control strategies are evaluated. After membrane selection and parameter optimization, concentration factors and diafiltration volumes are also defined. By optimizing the filtration mode of operation, it is possible to achieve product recoveries of approximately 80%. Overall, the process time is decreased by 30%, its scalability is improved, and the costs are reduced due to the removal of chromatography and associated buffer consumptions, cleaning, and its validation steps.


Assuntos
Biotecnologia/métodos , Vírus da Influenza A , Ultrafiltração/métodos , Vírion/isolamento & purificação , Animais , Linhagem Celular , Vacinas contra Influenza , Membranas Artificiais , Esterilização , Ultrafiltração/instrumentação , Vacinas de Partículas Semelhantes a Vírus
15.
Methods Mol Biol ; 1922: 211-218, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30838579

RESUMO

The extracellular matrix of the bone and dentin contains several non-collagenous proteins (NCPs). One category of NCPs is termed the SIBLING (small integrin-binding ligand, N-linked glycoprotein) family, which includes osteopontin (OPN), bone sialoprotein (BSP), dentin matrix protein 1 (DMP1), dentin sialophosphoprotein (DSPP), etc. These proteins have abundant phosphoserines, aspartic acids, and glutamic acids. In this protocol, we describe the extraction of NCPs from the bone and dentin matrices using guanidine-HCl/EDTA and the isolation of polyanionic SIBLINGs from NCPs using ion-exchange fast protein liquid chromatography (FPLC) to separate the differentially charged proteins into different fractions through a gradient elution by NaCl.


Assuntos
Osso e Ossos/química , Cromatografia por Troca Iônica/métodos , Dentina/química , Proteínas da Matriz Extracelular/isolamento & purificação , Sialoproteína de Ligação à Integrina/isolamento & purificação , Osteopontina/isolamento & purificação , Fosfoproteínas/isolamento & purificação , Sialoglicoproteínas/isolamento & purificação , Animais , Cromatografia por Troca Iônica/instrumentação , Ácido Edético/química , Desenho de Equipamento , Matriz Extracelular/química , Guanidina/química , Ácido Clorídrico/química , Camundongos , Cloreto de Sódio/química , Ultrafiltração/instrumentação , Ultrafiltração/métodos
16.
Anal Bioanal Chem ; 411(11): 2327-2338, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30790023

RESUMO

In asymmetrical flow field-flow fractionation (AF4), similar to other separation techniques, mass recovery and overloading require special attention in order to obtain quantitative results. We conducted a systematic study with five globular proteins of different molecular weight (36.7-669 kDa) and isoelectric point (4.0-6.5), and ultrafiltration membranes that are commonly used in aqueous AF4, regenerated cellulose (RC) and polyethersulfone (PES). Phosphate-buffered saline (PBS) with ionic strength 0.15 M and pH 7.2 was used as the carrier liquid in this study. The actual molecular weight cutoff (MWCO) was found to be higher than the nominal value and varied between membranes of different chemistry but the same nominal MWCO. Adsorption on the membrane was found to be dependent on the membrane chemistry (RC had lower adsorption compared to PES), and independent of the protein standard for the examined proteins. On the other hand, the mass overloading effects (i.e., higher retention times, peak broadening, and fronting peaks) were significantly more pronounced for γ-globulin than for the other proteins. The overloading effects could be rationalized with the increase of the local viscosity close to the membrane, depending on the properties of the proteins, and we derived theoretical equations that related the dependency of the migration velocity on the protein concentration through this non-ideal viscosity effect.


Assuntos
Fracionamento por Campo e Fluxo/instrumentação , Proteínas/análise , Ultrafiltração/instrumentação , Algoritmos , Animais , Bovinos , Desenho de Equipamento , Fracionamento por Campo e Fluxo/métodos , Cavalos , Hidrodinâmica , Concentração Osmolar , Permeabilidade , Mapas de Interação de Proteínas , Proteínas/metabolismo , Ultrafiltração/métodos , Viscosidade
17.
J Biosci Bioeng ; 128(1): 103-109, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30792124

RESUMO

Ultrafiltration membrane harvesting of Scenedesmus acuminatus was tested using alternative feed (AF) directions, i.e., bottom feed-top feed cycle and traditional bottom feed (BF). Both operations were investigated to compare the membrane performance and membrane fouling in microalgal harvesting process by scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and Fourier transform infrared (FTIR). The results showed that when the AF was used with and without backwashing, average flux increased by 27.9% and 17.9%, respectively, comparing with BF (68 L m-2 h-1) and the final dry weight reached 197 g L-1 and 175.8 g L-1, respectively. Microalgal cell deposition on AF membrane was reduced from 1.44 × 105 cell cm-2 on BF membrane to 7.12 × 104 cell cm-2 on AF membrane, according to SEM observation. The protein and polysaccharides on the AF membrane surface were also reduced according to CLSM and FTIR analysis. Fouling analysis along the fiber length revealed that fouling was most severe at the top section for BF as a result of a lower shear rate at the outlet. AF operation generated dynamic filtration by frequently switching flow directions, increasing the shear rate at both the top and bottom of the fibers, and therefore filtration and clean process simultaneously provided good performance.


Assuntos
Separação Celular , Filtração , Membranas Artificiais , Scenedesmus/isolamento & purificação , Purificação da Água , Reatores Biológicos/microbiologia , Separação Celular/instrumentação , Separação Celular/métodos , Filtração/instrumentação , Filtração/métodos , Hidrodinâmica , Microalgas , Ultrafiltração/instrumentação , Ultrafiltração/métodos , Purificação da Água/instrumentação , Purificação da Água/métodos
18.
Chemosphere ; 223: 204-210, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30780031

RESUMO

A new, environmental friendly, polysilicate ferric manganese (PSFM) coagulant, composed of Fe, Mn and Si, was designed and developed. As part of the process, the PSFM flocs were then deposited onto an ultrafiltration (UF) membrane to increase the removal of active dyes and its antifouling properties in the presence of the active dye was tested. Influencing factors, such as dosage of coagulant and solution pH, were systematically investigated and included as the process optimization. The results show that PSFM flocs were well distributed on the membrane surface and a dense and homogeneous deposition layer was formed under optimal conditions. According to the characterization of PSFM floc by Fourier infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), the major phase of PSFM floc is determined to be MnxFeySizOw(OH)i and the functional groups of this component contribute positively to the coagulation performance. The removal rate of the active yellow dye reached 86% at pH 5.0 with small and regular floc formed in the dense deposition layers. At pH 11.0 loose deposition layers were formed by large flocs and the removal of the active yellow dye reduce to 11%. Therefore, PSFM has a commendable potential to be used for producing a kind of deposited UF membrane with an excellent performance by controlling the forms of flocs and the deposition layers, which is the key mechanism to achieve a high efficiency for removal of active yellow dye.


Assuntos
Corantes/isolamento & purificação , Membranas Artificiais , Ultrafiltração/métodos , Purificação da Água/métodos , Compostos Férricos/química , Floculação , Manganês/química , Silicatos/química , Ultrafiltração/instrumentação
19.
Food Environ Virol ; 11(2): 167-177, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30756312

RESUMO

Ultrafiltration (UF) membranes are increasingly being used for wastewater reclamation treatment for their high removal of pathogens and suspended solids. However, breakage of UF membrane fibers could allow leakage of pathogens into the permeate and create health risks in the use of reclaimed water. Here, we assessed the log10 reduction value (LRV) of human enteric viruses and microbial indicators of new and aged UF modules in a pilot-scale UF process to evaluate the influence of fiber breakage. Norovirus genotypes I and II, Aichi virus, and Escherichia coli were not detected in any permeate samples of intact UF modules, but were detected in samples of damaged UF modules. LRVs of all microorganisms assayed decreased as fiber breakage of new UF modules increased, with maximum decreases of > 3.3 log10. Fiber breakage in the aged UF modules did not decrease LRVs of somatic coliphages and MS2, but breakage in the new UF modules did decrease them. Intact new UF modules gave higher LRVs than intact aged UF modules. When the LRV of intact UF module was assumed to be 1 or 2 log10, increasing fiber breakage did not significantly decrease the predicted LRV, but when it was ≥ 3 log10, it did decrease LRV, in good agreement with measured LRVs in the degraded UF modules. These results suggest that the LRV of intact UF modules affects the decrease in LRV and confirm the leakage of human enteric viruses following fiber breakage in UF modules of different ages in the UF process of wastewater reclamation.


Assuntos
Ultrafiltração/métodos , Águas Residuárias/química , Purificação da Água/métodos , Adsorção , Escherichia coli/química , Escherichia coli/isolamento & purificação , Kobuvirus/química , Kobuvirus/isolamento & purificação , Membranas Artificiais , Norovirus/química , Norovirus/isolamento & purificação , Ultrafiltração/instrumentação , Águas Residuárias/microbiologia , Águas Residuárias/virologia , Purificação da Água/instrumentação
20.
Isr Med Assoc J ; 21(1): 5-9, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30685897

RESUMO

BACKGROUND: Dialysate purity contributes to the inflammatory response that afflicts hemodialysis patients. OBJECTIVES: To compare the clinical and laboratory effects of using ultrapure water produced by a water treatment system including two reverse osmosis (RO) units in series, with a system that also includes an ultrapure filter (UPF). METHODS: We performed a retrospective study in 193 hemodialysis patients during two periods: period A (no UPF, 6 months) and period B (same patients, with addition of UPF, 18 months), and a historical cohort of patients treated in the same dialysis unit 2 years earlier, which served as a control group. RESULTS: Mean C-reactive protein, serum albumin and systolic blood pressure worsened in period B compared to period A and in the controls. CONCLUSIONS: A double RO system to produce ultrapure water is not inferior to the use of ultrapure filters.


Assuntos
Soluções para Diálise/química , Diálise Renal/instrumentação , Ultrafiltração/instrumentação , Purificação da Água/instrumentação , Idoso , Pressão Sanguínea/fisiologia , Proteína C-Reativa/análise , Feminino , Humanos , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Osmose , Diálise Renal/métodos , Estudos Retrospectivos , Albumina Sérica/análise , Purificação da Água/métodos
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