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1.
Molecules ; 26(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34206027

RESUMO

The utilization of biorefinery lignins as a renewable resource for the production of bio-based chemicals and materials remain a challenge because of the high polysaccharide content of this variety of lignins. This study provides two simple methods; (i) the alkaline hydrolysis-acid precipitation method and (ii) the acid hydrolysis method for the removal of polysaccharides from polymeric biorefinery lignin samples. Both purification strategies are optimized for two different hardwood hydrolysis lignins, HL1 and HL2, containing 15.1% and 10.1% of polysaccharides, respectively. The treated lignins are characterized by polysaccharide content, molecular weight, hydroxyl content, and Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR). Preliminary techno-economic calculations are also carried out for both purification processes to assess the economic potential of these technologies. The results indicate that both protocols could be used for the purification of HL1 and HL2 hydrolysis lignins because of the minimal polysaccharide content obtained in the treated lignins. Nevertheless, from an industrial and economic perspective the acid hydrolysis technology using low acid concentrations and high temperatures is favored over the alkaline hydrolysis-acid precipitation strategy.


Assuntos
Lignina/química , Polissacarídeos/análise , Madeira/química , Biotecnologia , Precipitação Química , Hidrólise , Peso Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Molecules ; 26(10)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067627

RESUMO

Biomineralization, a well-known natural phenomenon associated with various microbial species, is being studied to protect and strengthen building materials such as concrete. We characterized Rhodococcus erythreus S26, a novel urease-producing bacterium exhibiting CaCO3-forming activity, and investigated its ability in repairing concrete cracks for the development of environment-friendly sealants. Strain S26 grown in solid medium formed spherical and polygonal CaCO3 crystals. The S26 cells grown in a urea-containing liquid medium caused culture fluid alkalinization and increased CaCO3 levels, indicating that ureolysis was responsible for CaCO3 formation. Urease activity and CaCO3 formation increased with incubation time, reaching a maximum of 2054 U/min/mL and 3.83 g/L, respectively, at day four. The maximum CaCO3 formation was achieved when calcium lactate was used as the calcium source, followed by calcium gluconate. Although cell growth was observed after the induction period at pH 10.5, strain S26 could grow at a wide range of pH 4-10.5, showing its high alkali tolerance. FESEM showed rhombohedral crystals of 20-60 µm in size. EDX analysis indicated the presence of calcium, carbon, and oxygen in the crystals. XRD confirmed these crystals as CaCO3 containing calcite and vaterite. Furthermore, R. erythreus S26 successfully repaired the artificially induced large cracks of 0.4-0.6 mm width.


Assuntos
Carbonato de Cálcio/metabolismo , Materiais de Construção/microbiologia , Rhodococcus/metabolismo , Álcalis , Biomineralização/fisiologia , Carbonato de Cálcio/química , Precipitação Química
3.
Molecules ; 26(10)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34068926

RESUMO

Icaritin is a promising anti-hepatoma drug that is currently being tested in a phase-III clinical trial. A novel combination of amorphization and nanonization was used to enhance the oral bioavailability of icaritin. Amorphous icaritin nanoparticles (AINs) were prepared by a reactive precipitation technique (RPT). Fourier transform infrared spectrometry was used to investigate the mechanism underlying the formation of amorphous nanoparticles. AINs were characterized via scanning electron microscopy, X-ray powder diffraction, and differential scanning calorimetry. Our prepared AINs were also evaluated for their dissolution rates in vitro and oral bioavailability. The resultant nanosized AINs (64 nm) were amorphous and exhibited a higher dissolution rate than that derived from a previous oil-suspension formulation. Fourier transform infrared spectroscopy (FTIR) revealed that the C=O groups from the hydrophilic chain of polymers and the OH groups from icaritin formed hydrogen bonds that inhibited AIN crystallization and aggregation. Furthermore, an oral administration assay in beagle dogs showed that Cmax and AUClast of the dried AINs formulation were 3.3-fold and 4.5-fold higher than those of the oil-suspension preparation (p < 0.01), respectively. Our results demonstrate that the preparation of amorphous drug nanoparticles via our RPT may be a promising technique for improving the oral bioavailability of poorly water-soluble drugs.


Assuntos
Precipitação Química , Flavonoides/síntese química , Nanopartículas/química , Animais , Cães , Epimedium/anatomia & histologia , Epimedium/química , Flavonoides/sangue , Flavonoides/química , Flavonoides/farmacocinética , Masculino , Nanopartículas/ultraestrutura , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
Artigo em Inglês | MEDLINE | ID: mdl-33989987

RESUMO

OBJECTIVE: To optimize a screening method for macroprolactinemia and improve the accuracy of free prolactin (freePRL) detection. METHOD: Overall efficiency, calculated as the product of the immunoglobulin G (IgG) precipitation rate and the freePRL recovery rate were employed to determine the concentration of the precipitant polyethylene glycol (PEG). Then, an optimized screening method for macroprolactinemia was established. The concentrations of freePRL, obtained by gel filtration chromatography (GFC), from 66 cases were used as the gold standard, and the sensitivity, specificity, accuracy and precision of the optimized and traditional methods for detecting macroprolactinemia were compared. RESULTS: (1) The IgG precipitation rate increased with increasing PEG6000 concentration, and the freePRL recovery rate decreased with increasing PEG6000 concentration; the overall efficiency first increased and then decreased. When the IgG concentrations in the mixture were 10 g/L, 25 g/L and 40 g/L, the concentrations of PEG6000 with the highest overall efficiency were 24%, 20% and 18%, respectively. (2) The effect of high and low IgG on the overall efficiency was 4.7% when using 20% PEG6000, which was lower than the effects when using 18% or 24% PEG6000 (9.2% and 13.2%). (3) In the optimized method established using 20% PEG6000, the macroprolactin (macroPRL) chromatographic peak disappeared, but the freePRL chromatographic peak was retained. The sensitivity of this macroprolactinemia screening method was 96.7%, and the specificity was 100%. (4) The freePRL concentrations obtained by the optimized method for samples from 30 macroprolactinemia cases and 36 true hyperprolactinemia cases were 15.8 (10.2-21.4) ng/mL and 60.2 (51.8-79.9) ng/mL; the concentrations were similar to those obtained using the GFC method (16.3 (11.9-27.2) ng/mL and 68.1 (49.5-92.9) ng/mL, respectively (p > 0.05)) and higher than those obtained using the traditional method (9.1 (6.1-17.6) ng/mL and 51.4 (43.7-71.9) ng/mL), respectively, p < 0.05)). (5) The relative deviation between the optimized and GFC methods was -7.0%, which was significantly lower than the relative deviation between the traditional and GFC methods (-21.4%, p < 0.01). (6) The in-batch coefficients of variation (CVs) for the dual-level quality control materials measured by the optimized method were 1.88% and 1.87%, and the within-laboratory CVs were 2.55% and 2.29%, which were slightly lower than the in-batch CVs (1.93% and 2.81%) and within-laboratory CVs (2.75% and 2.81%) measured by the traditional method. CONCLUSION: The established optimized method for screening macroprolactinemia using 20% PEG6000 as a precipitant can completely precipitate macroPRL components and effectively retain freePRL components. Compared with traditional methods, the optimized method is simpler, more accurate and more stable for the quantitative detection of freePRL.


Assuntos
Cromatografia em Gel/métodos , Hiperprolactinemia/diagnóstico , Prolactina/sangue , Precipitação Química , Humanos , Imunoglobulina G/química , Polietilenoglicóis/química , Sensibilidade e Especificidade
5.
J Environ Sci (China) ; 104: 365-375, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33985739

RESUMO

Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(II), which is a valuable metal. In this study, the precipitation of Ni(II) from strongly acidic wastewater using sodium dimethyldithiocarbamate (DDTC) as the precipitant was evaluated. The effects of various factors on precipitation were investigated, and the precipitation mechanism was also identified. Finally, the nickel in the precipitates was recovered following a pyrometallurgical method. The results show that, under optimised conditions (DDTC:Ni(II) molar ratio = 4:1; temperature = 25 °C), the Ni(II) removal efficiency reached 99.3% after 10 min. In strongly acidic wastewater, the dithiocarbamate group of DDTC can react with Ni(II) to form DDTCNi precipitates. Further recovery experiments revealed that high-purity NiO can be obtained by the calcination of DDTCNi precipitates, with the nickel recovery efficiency reaching 98.2%. The gas released during the calcination process was composed of NO2, CS2, H2O, CO2, and SO2. These results provide a basis for an effective Ni(II) recovery method from strongly acidic wastewater.


Assuntos
Níquel , Águas Residuárias , Ácidos , Precipitação Química , Metais
6.
Water Res ; 200: 117242, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34052476

RESUMO

The effect of mixing in the modelling of processes based on mass transfer phenomena is commonly ignored in wastewater treatment industry. In this contribution, the effect of the average shear rate in the nucleation and growth rates of struvite is analyzed by combining experimental data with simulation results obtained with a previously presented mass-based discretized population balance model. According to the obtained results, the effect of the average shear rate is identifiable for the selected data and mechanisms. Therefore, it should be considered when a detailed modelling of the process is needed. Consequently, in this contribution, the average shear rate has been decoupled from the kinetic constants. In addition, kinetic rates where it is explicitly included as a power law function have been proposed. The exponents in these power law functions for the primary homogeneous nucleation and growth are 1.3 and 0.3, respectively. Considering shear rate effects allowed to see in the simulation outputs experimentally observed effects: a faster pH decay and smaller particle distribution for increasing mixing intensities.


Assuntos
Compostos de Magnésio , Fosfatos , Precipitação Química , Cinética , Estruvita
7.
Anal Chim Acta ; 1168: 338612, 2021 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-34051997

RESUMO

The process of protein precipitation can be used to decipher the interaction of ligand and protein. For example, the classic Thermal Proteome Profiling (TPP) method uses heating as the driving force for protein precipitation, to discover the drug target protein. Under heating or other denature forces, the target protein that binds with the drug compound will be more resistant to precipitation than the free protein. Similar to thermal stress, mechanical stress can also induce protein precipitation. Upon mechanical stress, protein will gradually precipitate along with protein conformational changes, which can be exploited for the study of the ligand-protein interaction. Herein, we proposed a Mechanical Stress Induced Protein Precipitation (MSIPP) method for drug target deconvolution. Its streamlined workflow allows in situ sample preparation on the surface of microparticles, from protein precipitation to digestion. The mechanical stress was generated by vortexing the slurry of protein solution and microparticle materials. The mechanical stress induced protein precipitate was captured by the microparticles, which guarantees the MSIPP method to be scalable and user-friendly. The MSIPP method was successfully applied to four drug compounds, Methotrexate, Raltitrexed, SHP099, Geldanamycin and a pan-inhibitor of protein kinases, Staurosporine. Besides, DHFR was demonstrated to be a target of Raltitrexed, which has not been revealed by any other modification-free drug target discovery method yet. Thus, MSIPP is a complementary method to other drug target screening methods.


Assuntos
Sistemas de Liberação de Medicamentos , Preparações Farmacêuticas , Precipitação Química , Avaliação Pré-Clínica de Medicamentos , Estaurosporina , Estresse Mecânico
8.
Curr Protoc ; 1(4): e130, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: covidwho-1202693

RESUMO

The most common method for RNA detection involves reverse transcription followed by quantitative polymerase chain reaction (RT-qPCR) analysis. Commercial one-step master mixes-which include both a reverse transcriptase and a thermostable polymerase and thus allow performing both the RT and qPCR steps consecutively in a sealed well-are key reagents for SARS-CoV-2 diagnostic testing; yet, these are typically expensive and have been affected by supply shortages in periods of high demand. As an alternative, we describe here how to express and purify Taq polymerase and M-MLV reverse transcriptase and assemble a homemade one-step RT-qPCR master mix. This mix can be easily assembled from scratch in any laboratory equipped for protein purification. We also describe two simple alternative methods to prepare clinical swab samples for SARS-CoV-2 RNA detection by RT-qPCR: heat-inactivation for direct addition, and concentration of RNA by isopropanol precipitation. Finally, we describe how to perform RT-qPCR using the homemade master mix, how to prepare in vitro-transcribed RNA standards, and how to use a fluorescence imager for endpoint detection of RT-PCR amplification in the absence of a qPCR machine In addition to being useful for diagnostics, these versatile protocols may be adapted for nucleic acid quantification in basic research. © 2021 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparation of a one-step RT-qPCR master mix using homemade enzymes Basic Protocol 2: Preparation of swab samples for direct RT-PCR Alternate Protocol 1: Concentration of RNA from swab samples by isopropanol precipitation Basic Protocol 3: One-step RT-qPCR of RNA samples using a real-time thermocycler Support Protocol: Preparation of RNA concentration standards by in vitro transcription Alternate Protocol 2: One-step RT-PCR using endpoint fluorescence detection.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , RNA Viral/isolamento & purificação , SARS-CoV-2/isolamento & purificação , COVID-19/virologia , Teste de Ácido Nucleico para COVID-19/economia , Precipitação Química , Humanos , RNA Viral/genética , SARS-CoV-2/genética , Fatores de Tempo
9.
Curr Protoc ; 1(4): e130, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33905620

RESUMO

The most common method for RNA detection involves reverse transcription followed by quantitative polymerase chain reaction (RT-qPCR) analysis. Commercial one-step master mixes-which include both a reverse transcriptase and a thermostable polymerase and thus allow performing both the RT and qPCR steps consecutively in a sealed well-are key reagents for SARS-CoV-2 diagnostic testing; yet, these are typically expensive and have been affected by supply shortages in periods of high demand. As an alternative, we describe here how to express and purify Taq polymerase and M-MLV reverse transcriptase and assemble a homemade one-step RT-qPCR master mix. This mix can be easily assembled from scratch in any laboratory equipped for protein purification. We also describe two simple alternative methods to prepare clinical swab samples for SARS-CoV-2 RNA detection by RT-qPCR: heat-inactivation for direct addition, and concentration of RNA by isopropanol precipitation. Finally, we describe how to perform RT-qPCR using the homemade master mix, how to prepare in vitro-transcribed RNA standards, and how to use a fluorescence imager for endpoint detection of RT-PCR amplification in the absence of a qPCR machine In addition to being useful for diagnostics, these versatile protocols may be adapted for nucleic acid quantification in basic research. © 2021 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparation of a one-step RT-qPCR master mix using homemade enzymes Basic Protocol 2: Preparation of swab samples for direct RT-PCR Alternate Protocol 1: Concentration of RNA from swab samples by isopropanol precipitation Basic Protocol 3: One-step RT-qPCR of RNA samples using a real-time thermocycler Support Protocol: Preparation of RNA concentration standards by in vitro transcription Alternate Protocol 2: One-step RT-PCR using endpoint fluorescence detection.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , RNA Viral/isolamento & purificação , SARS-CoV-2/isolamento & purificação , COVID-19/virologia , Teste de Ácido Nucleico para COVID-19/economia , Precipitação Química , Humanos , RNA Viral/genética , SARS-CoV-2/genética , Fatores de Tempo
10.
Methods Mol Biol ; 2300: 11-16, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33792867

RESUMO

Precipitation is a critical step to recover RNA of high purity. This chapter describes the principles of alcoholic precipitation as well as a standard, basic protocol with key advices to observe, but numerous variations on the theme are discussed. Indeed, several important parameters, such as the choice of salt, alcohol, or carrier, have to be considered to improve the efficiency of precipitation and the yield of RNA recovery.


Assuntos
RNA de Transferência/química , RNA de Transferência/isolamento & purificação , Leveduras/genética , Álcoois/química , Precipitação Química , RNA Fúngico/química , Sais/química
11.
Methods Mol Biol ; 2227: 43-49, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33847929

RESUMO

Detection of complement activation products can be carried out in a number of ways, and different methods are used in different laboratories. No international standard for measuring complement activation in the clinical setting has been agreed upon.Here we describe a modified assay for measuring C3dg. The assay is simple, inexpensive and stable. The estimation of C3dg directly reflects complement turnover independently of activation pathway.


Assuntos
Precipitação Química , Complemento C3b/análise , Imunofluorescência/métodos , Fragmentos de Peptídeos/análise , Animais , Biomarcadores/análise , Biomarcadores/sangue , Eletroforese das Proteínas Sanguíneas , Ativação do Complemento/fisiologia , Complemento C3b/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/métodos , Fluorimunoensaio/métodos , Humanos , Imunoeletroforese/métodos , Inflamação/sangue , Inflamação/diagnóstico , Mediadores da Inflamação/análise , Mediadores da Inflamação/sangue , Fragmentos de Peptídeos/isolamento & purificação , Polietilenoglicóis/química , Coelhos
12.
Artigo em Inglês | MEDLINE | ID: mdl-33678136

RESUMO

The physicochemical treatment (PT) of food industry wastewater was investigated. In the first stage, calcium magnesium acetate (CaMgAc4) was synthesized using eggshell (biocalcium), magnesium oxide and acetic acid in a 1:1:1 stoichiometric ratio. In the synthesis process, the thermodynamic parameters (ΔH, ΔS and ΔG) indicated that the reaction was endothermic and spontaneous. The samples were characterized by infrared spectroscopy (IR), scanning electronic microscopy (SEM), X-ray diffraction (XRD) and electron X-ray dispersive spectroscopy (EDS). CaMgAc4 was used to precipitate the phosphate matter. IR analysis revealed that the main functional groups were representative of the acetate compounds and the presence of OH- groups and carbonates. In the physicochemical treatment, a response surface design was used to determine the variables that influence the process (pH, t, and concentration), and the response variable was phosphorus removal. The treatments were carried out in the wastewater industry with an initial concentration of 658 mg/L TP. The optimal conditions of the precipitation treatment were pH 12, time 12 min, and a CaMgAc4 concentration of 13.18 mg/L. These conditions allowed the total elimination (100%) of total phosphorus and phosphates, 81.43% BOD5 and 81.0% COD, 98.9% turbidity, 95.01% color, and 92% nitrogen matter.


Assuntos
Cálcio/química , Casca de Ovo/química , Indústria Alimentícia , Fosfatos/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Acetatos/química , Animais , Precipitação Química , Concentração de Íons de Hidrogênio , Óxido de Magnésio/química , Fosfatos/análise , Fosfatos/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
13.
Int J Pharm ; 600: 120505, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33753162

RESUMO

This review focuses on options available to a pharmaceutical scientist to predict in vivo supersaturation and precipitation of poorly water-soluble drugs. As no single device or system can simulate the complex gastrointestinal environment, a combination of appropriate in vitro tools may be utilized to get optimal predictive information. To address the empirical issues encountered during small-scale and full-scale in vitro predictive testing, theoretical background and relevant case studies are discussed. The practical considerations for selection of appropriate tools at various stages of drug development are recommended. Upcoming technologies that have potential to further reduce in vivo studies and expedite the drug development process are also discussed.


Assuntos
Preparações Farmacêuticas , Água , Precipitação Química , Solubilidade
14.
Food Chem ; 352: 129354, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33677209

RESUMO

Biosensors have been widely applied in tests for allergens, but on-site detection remains a challenge. Herein, we proposed a detection procedure for peanut Ara h 1 as a representative allergen, which was extracted from a cookie, thereby minimising the need for any complex pretreatment that was difficult to perform, and enabling the visual detection of the target without the use of analytical equipment. The extraction procedure was performed in less than 30 min using a syringe and filter (0.45 µm). The detection method for Ara h 1 was based on the aggregation of switchable linkers (SL) and gold nanoparticles (AuNP), and the presence of 0.19 mg peanut protein per 30 g of cookie could be confirmed within 30 min based on the AuNP/SL concentration ratio by the precipitation. This proposed procedure could be successfully applied to the detection of a wide range of food allergens.


Assuntos
Antígenos de Plantas/análise , Antígenos de Plantas/isolamento & purificação , Precipitação Química , Ouro/química , Proteínas de Membrana/análise , Proteínas de Membrana/isolamento & purificação , Nanopartículas Metálicas/química , Proteínas de Plantas/análise , Proteínas de Plantas/isolamento & purificação , Antígenos de Plantas/imunologia , Humanos , Proteínas de Membrana/imunologia , Hipersensibilidade a Amendoim , Proteínas de Plantas/imunologia
15.
Carbohydr Polym ; 261: 117881, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766368

RESUMO

Marine green algae biomass residue (ABR), a waste by-product of Dunaliella tertiolecta, left behind after the extraction of oil from the algal biomass, was utilized for the fabrication of cellulose nanocrystals (CNCs). The fabricated sulphuric acid hydrolysed CNCs had needle-like morphology, with dominant cellulose type I polymorph and a high crystallinity index of 89 %. ICP-MS elemental analysis confirmed the presence of a variety of minerals in the ABR. Washed ABR (WABR)/PLA and CNC/PLA bio-composite films were developed via solvent casting technique with varying bio-filler loadings for comparing their effectiveness on the crystallization behaviour of PLA. FESEM, FTIR, XRD and TGA were used to characterize the bio-fillers. The nucleating and crystallization behaviour of the bio-composite films were confirmed using DSC, SAXS and POM analysis which indicated better effectiveness of CNCs with a significant reduction in cold crystallization temperature, and noteworthy increment in crystallinity and spherulite growth rate.


Assuntos
Celulose/isolamento & purificação , Clorófitas/química , Nanopartículas , Poliésteres/química , Biomassa , Celulose/química , Celulose/farmacologia , Precipitação Química/efeitos dos fármacos , Clorófitas/metabolismo , Cristalização , Nanopartículas/química , Nanopartículas/metabolismo , Espalhamento a Baixo Ângulo , Difração de Raios X
16.
Methods Mol Biol ; 2278: 101-115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33649951

RESUMO

This chapter describes some of the available methods to assess EPS production in bifidobacteria, being largely based on those developed for the same purpose for members of the lactic acid bacteria group. The first step is detection of putative EPS-producing bifidobacteria based on a mucoid and/or ropy phenotype. Next, a basic procedure is described for the isolation of the glycan polymer based on the release from bifidobacterial cells grown and collected from the surface of agar-MRSc ("crude EPS"), followed by a purification procedure intended to remove other bacterial macromolecules (DNA and proteinaceous material) to generate "purified EPS." Finally, several methods used for quantification and physical-chemical characterization of isolated/purified polysaccharide are outlined.


Assuntos
Bifidobacterium/química , Polissacarídeos Bacterianos/isolamento & purificação , Técnicas de Cultura de Células/métodos , Centrifugação/métodos , Precipitação Química , Diálise/métodos , Liofilização/métodos , Polissacarídeos/isolamento & purificação
17.
PLoS One ; 16(2): e0240763, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33561160

RESUMO

Microbial-induced calcium carbonate precipitation (MICP) is a biological process inducing biomineralization of CaCO3. This can be used to form a solid, concrete-like material. To be able to use MICP successfully to produce solid materials, it is important to understand the formation process of the material in detail. It is well known that crystallization surfaces can influence the precipitation process. Therefore, we present in this contribution a systematic study investigating the influence of calcite seeds on the MICP process. We focus on the changes in the pH and changes of the optical density (OD) signal measured with absorption spectroscopy to analyze the precipitation process. Furthermore, optical microscopy was used to visualize the precipitation processes in the sample and connect them to changes in the pH and OD. We show, that there is a significant difference in the pH evolution between samples with and without calcite seeds present and that the shape of the pH evolution and the changes in OD can give detailed information about the mineral precipitation and transformations. In the presented experiments we show, that amorphous calcium carbonate (ACC) can also precipitate in the presence of initial calcite seeds and this can have implications for consolidated MICP materials.


Assuntos
Biomineralização/fisiologia , Carbonato de Cálcio/química , Materiais de Construção/microbiologia , Carbonato de Cálcio/metabolismo , Carbonatos/química , Precipitação Química , Microscopia/métodos , Minerais/química , Solo , Sporosarcina/metabolismo
18.
Transfusion ; 61(4): 1035-1040, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33634868

RESUMO

BACKGROUND: Cryoprecipitate (CRYO) is neither produced nor supplied by the Japanese Red Cross Society. A novel CRYO extraction method established in-house by modifying a thaw-siphon technique was demonstrated in this study. STUDY DESIGN AND METHODS: A pack of fresh frozen plasma was thawed and equally divided into two bags for CRYO extraction by different methods. CRYO was extracted from the blood plasma using a standard centrifugation method and our modified thaw-siphon method (Bokutoh-siphon method; B method). The two different CRYOs extracted were analyzed to compare the differences in the amount of fibrinogen recovered, clotting factors extracted, and clotting activity. RESULTS: The amount of fibrinogen in the CRYO extracted using the B-siphon method was similar to that obtained using the standard method (recovery of fibrinogen: B-siphon method: 71.2% vs. standard method: 61.0%). The amount of clotting XIII factor extracted using the B-siphon method was significantly lower than those extracted using the standard method. On the other hand, clotting II, V factors, and C1q esterase inhibitor not concentrated in CRYO content from the B-siphon method were significantly higher than that from the standard method. CONCLUSION: A new in-house CRYO preparation method was established by modifying a previously used thaw-siphon method. A coagulation factor-rich CRYO was extracted from plasma frozen at -40°C along with the first fraction of thawed plasma, without using a large-capacity refrigerated centrifuge for blood bags.


Assuntos
Fatores de Coagulação Sanguínea/análise , Centrifugação/instrumentação , Criopreservação/métodos , Fibrinogênio/análise , Plasma/química , Fatores de Coagulação Sanguínea/metabolismo , Precipitação Química , Proteína Inibidora do Complemento C1/metabolismo , Fator V/análise , Fator VIII/análise , Fibrinogênio/metabolismo , Humanos , Indicadores e Reagentes/química , Protrombina/análise
19.
Toxins (Basel) ; 13(2)2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33572944

RESUMO

Cyanobacterial blooms and the associated release of cyanotoxins pose problems for many conventional water treatment plants due to their limited removal by typical unit operations. In this study, a conventional water treatment process consisting of coagulation, flocculation, sedimentation, filtration, and sludge dewatering was assessed in lab-scale experiments to measure the removal of microcystin-LR and Microcystis aeruginosa cells using liquid chromatography with mass spectrometer (LC-MS) and a hemacytometer, respectively. The overall goal was to determine the effect of recycling cyanotoxin-laden dewatered sludge supernatant on treated water quality. The lab-scale experimental system was able to maintain the effluent water quality below relevant the United States Environmental Protection Agency (US EPA) and World Health Organisation (WHO) standards for every parameter analyzed at influent concentrations of M. aeruginosa above 106 cells/mL. However, substantial increases of 0.171 NTU (Nephelometric Turbidity Unit), 7 × 104 cells/L, and 0.26 µg/L in turbidity, cyanobacteria cell counts, and microcystin-LR concentration were observed at the time of dewatered supernatant injection. Microcystin-LR concentrations of 1.55 µg/L and 0.25 µg/L were still observed in the dewatering process over 24 and 48 h, respectively, after the initial addition of M.aeruginosa cells, suggesting the possibility that a single cyanobacterial bloom may affect the filtered water quality long after the bloom has dissipated when sludge supernatant recycling is practiced.


Assuntos
Água Potável/microbiologia , Proliferação Nociva de Algas , Toxinas Marinhas/isolamento & purificação , Microcistinas/isolamento & purificação , Microcystis/isolamento & purificação , Esgotos/microbiologia , Microbiologia da Água , Purificação da Água , Qualidade da Água , Precipitação Química , Cromatografia Líquida , Filtração , Espectrometria de Massas , Microcystis/crescimento & desenvolvimento , Microcystis/metabolismo , Nefelometria e Turbidimetria
20.
PLoS One ; 16(2): e0246647, 2021.
Artigo em Inglês | MEDLINE | ID: covidwho-1060986

RESUMO

Re-opening of communities in the midst of the ongoing COVID-19 pandemic has ignited new waves of infections in many places around the world. Mitigating the risk of reopening will require widespread SARS-CoV-2 testing, which would be greatly facilitated by simple, rapid, and inexpensive testing methods. This study evaluates several protocols for RNA extraction and RT-qPCR that are simpler and less expensive than prevailing methods. First, isopropanol precipitation is shown to provide an effective means of RNA extraction from nasopharyngeal (NP) swab samples. Second, direct addition of NP swab samples to RT-qPCRs is evaluated without an RNA extraction step. A simple, inexpensive swab collection solution suitable for direct addition is validated using contrived swab samples. Third, an open-source master mix for RT-qPCR is described that permits detection of viral RNA in NP swab samples with a limit of detection of approximately 50 RNA copies per reaction. Quantification cycle (Cq) values for purified RNA from 30 known positive clinical samples showed a strong correlation (r2 = 0.98) between this homemade master mix and commercial TaqPath master mix. Lastly, end-point fluorescence imaging is found to provide an accurate diagnostic readout without requiring a qPCR thermocycler. Adoption of these simple, open-source methods has the potential to reduce the time and expense of COVID-19 testing.


Assuntos
COVID-19/diagnóstico , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/métodos , SARS-CoV-2/genética , COVID-19/virologia , Teste de Ácido Nucleico para COVID-19 , Precipitação Química , Proteínas do Nucleocapsídeo de Coronavírus/genética , Humanos , Limite de Detecção , Nasofaringe/virologia , Fosfoproteínas/genética , RNA Viral/isolamento & purificação , RNA Viral/metabolismo , SARS-CoV-2/isolamento & purificação
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