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1.
Chemosphere ; 255: 127055, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679637

RESUMO

Nanofiltration concentrated landfill leachate (NCLL) is produced during the integration process of biodegradation and nanofiltration, containing a large amount of recalcitrant dissolved organic matter (DOM). In this work, electrocatalytic oxidation technology was employed to degrade DOM in NCLL and spectroscopic technology was applied to explore the structural changes. The results showed that under the optimal experimental condition (pH = 2.0, NaCl concentration = 0.7%, Fe2(SO4)3 concentration = 0.8%, the retention time = 6 h), the removal rates of COD, TOC, and UV254 were 99.0%, 57.4%, 99.3% respectively. Ultraviolet-Visible (UV-Vis) spectral analysis showed that aromatic CC can be effectively degraded by electrocatalytic oxidation, resulting in decreases of aromaticity and molecular weight in NCLL. Two fluorescent components (terrestrial humic-like substances and fulvic-like substances) were identified in NCLL by parallel factor analysis, which can be effectively removed by electrocatalytic oxidation with removal rates of 99.9% and 90.5%, respectively. In addition, through two-dimensional correlation spectroscopic analysis, the sequence of structural changes of the DOM in NCLL was confirmed: unsaturated double bonds → fulvic-like components/aromatic structures → terrestrial humic-like components. These spectral characterization techniques can provide a deep understanding of the degradation pathways of DOM and provide new insights for the treatment of NCLL.


Assuntos
Poluentes Químicos da Água/química , Biodegradação Ambiental , Substâncias Húmicas/análise , Peso Molecular , Oxirredução , Poluentes Químicos da Água/análise
2.
J Chromatogr A ; 1621: 461081, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32349863

RESUMO

The chemical composition distribution (CCD) of three single site made ethylene/1-octene copolymers was investigated through offline-hyphenation of solvent gradient interaction chromatography (SGIC) with 1H NMR. Thus, a clear, non-linear correlation between SGIC elution time and chemical composition was found under the specific measurement conditions applied here. The application of 1H NMR as detection allowed to determine the CCD with unprecedented accuracy. 2D-LC of the copolymers revealed the correlation between CCD and molar mass distribution (MMD) in a quantitative manner. Furthermore, this approach allowed a comparison between the response behavior of an evaporative light scattering detector (ELSD, semi-quantitative, commonly applied in SGIC) and that of an infrared (IR) detector (quantitative, commonly applied in SEC). As a result, it could be shown that ELSD results are close to IR results for the system investigated here, in other words, the often-criticized semi-quantitative response behavior of the ELSD is affecting results in an acceptable manner.


Assuntos
Alcenos/análise , Cromatografia Líquida de Alta Pressão/métodos , Elastômeros/análise , Etilenos/análise , Polienos/análise , Calibragem , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Elastômeros/química , Peso Molecular , Espectroscopia de Prótons por Ressonância Magnética , Solventes/química , Temperatura , Fatores de Tempo
3.
Water Sci Technol ; 81(2): 301-308, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32333663

RESUMO

The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0-52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2-17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45-7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76-5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.


Assuntos
Resinas Acrílicas , Reatores Biológicos , Anaerobiose , Biodegradação Ambiental , Peso Molecular
4.
Ecotoxicol Environ Saf ; 196: 110547, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32244119

RESUMO

Large molecular weight pig biogas slurry (L-PBS) and small molecular weight pig biogas slurry (S-PBS) were separated from original pig biogas slurry (O-PBS) using a 100 kDa membrane. The original bioavailability and biosafety of L-PBS was very low. In order to enhance the total bioavailable dissolved organic nitrogen (TB-DON) and total bioavailable dissolved organic phosphorus (TB-DOP), optimum catalytic ozonation of L-PBS conditions were determined using Box-behnken design models (P < 0.0001) and intersection tests. The optimal values for ozone concentration, pH value, active catalyst concentration and reaction time were 2.63 mg·L-1, 6.48, 1.43 g·L-1 and 40 min, respectively. Catalytic ozonation can effectively decompose and transform 68.07% of L-PBS into S-PBS to improve content organic bioavailability, with a molecular weight distribution of 0-1 kDa (13.53%), 1-5 kDa (16.62%), 5-10 kDa (11.16%), 10-30 kDa (11.73%), 30-100 kDa (15.04%). Catalytic ozonation of L-PBS can reduce protein levels from 85.28% to 47.18%, but increases the proportion of fulvic and humic components from 10.22% to 32.67% and 4.51%-20.15%, respectively. Because catalytic ozonation changes the internal components and molecular weights of L-PBS, both saw increases in TB-DON and TB-DOP from 3.33% to 41.12% and 2.43%-37.88%, respectively, with a large number of TB-DON and TB-DOP derived from hydrophilic organic components during catalytic ozonation. These important internal mechanisms changed by catalytic ozonation can effectively reduce the ecotoxicity (IR, from 76.5% to 33.1%) and phytotoxicity (GI, enhanced from 35.4% to 70.3%) of L-PBS. Therefore, catalytic ozonation combined with membrane separation is a choice technology in improving the nutrition of biogas slurry and reduce its ecological risk.


Assuntos
Biocombustíveis , Ozônio/química , Animais , Catálise , Peso Molecular , Nitrogênio/análise , Fósforo/análise , Suínos
5.
PLoS One ; 15(4): e0231830, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32302352

RESUMO

Renal anemia is predominantly caused by a relative deficiency in erythropoietin (EPO). Conventional treatment for renal anemia includes the use of recombinant human EPO (rhEPO) or a long-acting erythropoiesis-activating agent named darbepoetin alfa, which is a modified rhEPO with a carbohydrate chain structure that differs from native hEPO. We have developed a biosimilar to darbepoetin alfa designated JR-131. Here, we comprehensively compare the physicochemical and biological characteristics of JR-131 to darbepoetin alfa. JR-131 demonstrated similar protein structure to the originator, darbepoetin alfa, by peptide mapping and circular dichroism spectroscopy. Additionally, mass spectroscopic analyses and capillary zone electrophoresis revealed similar glycosylation patterns between the two products. Human bone marrow-derived erythroblasts differentiated and proliferated to form colonies with JR-131 to a similar degree as darbepoetin alfa. Finally, JR-131 stimulated erythropoiesis and improved anemia in rats similarly to darbepoetin alfa. Our data show the similarity in physicochemical and biological properties of JR-131 to those of darbepoetin alfa, and JR-131 therefore represents a biosimilar for use in the treatment of renal anemia.


Assuntos
Medicamentos Biossimilares/farmacologia , Darbepoetina alfa/farmacologia , Eritropoese/efeitos dos fármacos , Anemia/tratamento farmacológico , Animais , Células CHO , Cricetinae , Cricetulus , Darbepoetina alfa/química , Modelos Animais de Doenças , Eletroforese Capilar , Glicosilação/efeitos dos fármacos , Rim/patologia , Masculino , Peso Molecular , Nefrectomia , Mapeamento de Peptídeos , Estrutura Secundária de Proteína , Ratos Sprague-Dawley , Açúcares/análise , Resultado do Tratamento
6.
Zhongguo Zhong Yao Za Zhi ; 45(1): 106-112, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-32237418

RESUMO

To explore the permeation mechanism of micro-molecule medicinal ingredients of water extract of tradition Chinese medicine(TCM) in membrane separation process. With phenolic acid components as the model solute, five phenolic acids with similar molecular weight and structure, namely gallic acid, protocatechuate acid, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid and salicylic acid, were selected in the PES membrane separation experiments. With the relative flux and the transmission rate as indexes, the scanning electron microscopy(SEM) and the electrochemical impedance spectroscopy(EIS) were used to analyze the permeation mechanism of different phenolic acid components. The results showed phenolic acids with similar molecular weight had different permeation behaviors, with decreased relative flux and increased solute permeation with the increase of solute concentration. According to the permeation behavior analyzed by the molecular structure of solute, the transmission rate of phenolic acids increased with the increase of the number of hydroxyl, and the order of substituent positions of phenolic acids based on the permeation rate as follows: para-substituted > meta-substitution > ortho-substitution. Electrochemical impedance spectroscopy reflected the role of charge repulsion in the membrane process; that is to say, the greater the resistance is, the less the solute permeation is. Therefore, the permeation phenomenon of the phenolic acid components in the PES membrane is not only the result of simple sieving mechanisms, but also has the effects of steric hindrance and charge repulsion during the membrane process.


Assuntos
Medicamentos de Ervas Chinesas/análise , Hidroxibenzoatos/isolamento & purificação , Membranas Artificiais , Medicina Tradicional Chinesa , Estrutura Molecular , Peso Molecular
7.
Chemosphere ; 253: 126728, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32298913

RESUMO

Nile perch wastewater was biodegraded using two Bacillus species to recover bioactive substances to enhance its reutilization value. The two Bacillus species successfully produced low-molecular-weight substances with a 47.8% degree of hydrolysis. The antioxidant activities of the Nile perch wastewater increased as the biodegradation proceeded, and the culture supernatant exhibited the highest DPPH (80.1%), ABTS (93.1%) and Fe2+ chelating (88.5%) antioxidant activities at 60 h. The antioxidant potential of the biodegraded Nile perch wastewater was found to be higher than those of other fish hydrolysates. Moreover, the biodegraded Nile perch wastewater exhibited effective antimicrobial activity against Vibrio vulnificus, exhibiting a minimal inhibitory concentration of 585 µg mL-1. Two-dimensional thin layer chromatography analysis revealed the specific amino acids responsible for the antioxidant activity, and molecular-weight cut-off ultrafiltration revealed that the <2-kDa fraction exhibited the highest antioxidant activity with the lowest IC50 values (0.43 and 0.22 mg mL-1 for DPPH and ABTS antioxidant activities, respectively). This is the first report of the reutilization of Nile perch wastewater as a natural antioxidant and antimicrobial ingredient for nutraceuticals.


Assuntos
Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Bacillus/metabolismo , Peptídeos/isolamento & purificação , Percas , Águas Residuárias/química , Aminoácidos/isolamento & purificação , Aminoácidos/farmacologia , Animais , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Biodegradação Ambiental , Compostos de Bifenilo/química , Quelantes/isolamento & purificação , Quelantes/farmacologia , Pesqueiros , Hidrólise , Peso Molecular , Peptídeos/farmacologia , Percas/crescimento & desenvolvimento , Picratos/química , Ultrafiltração , Vibrio vulnificus/efeitos dos fármacos
8.
Food Chem ; 322: 126645, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32335492

RESUMO

ß-Galactosidase formulations can be added to infant milks prior to feeding to reduce the level of lactose and to avoid symptoms of lactose intolerance. The hydrolysis of lactose affects osmolality, which is an important property of infant milk. This paper introduces novel ultrasonic technology for precision, real-time, non-destructive monitoring of osmolality of infant milks, including breast milk, during enzymatic hydrolysis of lactose by supplemental ß-galactosidases. This technology can be utilised in the development and testing of ß-galactosidase formulations. Additionally, ultrasonic real-time measurements of the average degree of polymerisation and molar mass of milk saccharides throughout the hydrolysis are discussed. Comparison of the ultrasonic results with discontinuous data of osmometry and HPLC showed an excellent agreement between the different techniques. The results elucidate the osmolality dynamics involved in the enzymatic hydrolysis of lactose in milks.


Assuntos
Fórmulas Infantis/química , Lactose/química , Leite Humano/química , Análise Espectral/métodos , Ultrassom/métodos , Animais , Bovinos , Feminino , Humanos , Hidrólise , Lactente , Peso Molecular , Oligossacarídeos/química , Concentração Osmolar , beta-Galactosidase/química
9.
Water Res ; 174: 115643, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32114015

RESUMO

Natural organic matter (NOM) can inhibit the photocatalytic degradation of organic micropollutants (OMPs) through inner filter effect, reactive oxygen species (ROS) scavenging, and competitive adsorption. However, previous studies have focused solely on the bulk properties of NOM and our understanding of the inhibition mechanism by NOM fractions during photocatalytic degradation of OMP is still fragmentary. In this study, five well-characterized different NOM samples (i.e., secondary treated wastewater, river water, and three standard NOM surrogates) were used to elucidate the inhibition mechanisms during photocatalytic degradation of carbamazepine (a model OMP) using TiO2 and its composites with carbon nanotubes (CNT-TiO2) under UVC and solar-light irradiation. The results indicated that terrestrially derived NOM with high aromaticity, a low oxygen/carbon atom ratio, and large molecular weight is the major fraction that participates in ROS scavenging, competitive adsorption, and inner filter effect. Furthermore, the modeling analysis suggested that inner filter effect due to NOM and ROS scavenging was the most influential inhibitory mechanism. In the case of secondary treated wastewater, the presence of high concentrations of inorganic species (e.g., PO43-, Cl-, and NO3-) together with NOM significantly reduced the photocatalytic degradation of carbamazepine. Overall, the methods and the results of this study provide a comprehensive understanding of the effects of NOM fractions on photocatalysis and highlight the need to further consider the interplay between NOM and background inorganic constituents in photocatalytic degradation of OMP.


Assuntos
Nanotubos de Carbono , Poluentes Químicos da Água , Purificação da Água , Adsorção , Carbamazepina , Peso Molecular , Fotólise
10.
Artigo em Inglês | MEDLINE | ID: mdl-32181694

RESUMO

In the past decade, Mexican coasts have received an enormous influx of macroalgae species, producing serious environmental and public health concerns. Here, we developed a green methodology to generate a new polymer from the lignin contained in the macroalgae. The methodology consists in lignin extraction-by-boiling and its subsequent polymerization with a laccase-like enzyme from the green algae Tetraselmis gracilis (Tg-laccase). Mass spectrometry revealed the presence of guaiacyl (G), p-hydroxyphenyl (H), and sinapyl alcohol as the main monolignols in the lignin from Sargassum sp. On the other hand, MALDI-TOF spectra shows an increase in the size of the lignin chain after enzymatic polymerization process with Tg-laccase. Besides, the characterization of the novel polymer -using 1H NMR, FTIR, SEC-FPLC, and UV/Vis- allowed establishing that during the polymerization process there is a decrease in the number of phenolic groups as well as loss of aromatic protons, which allowed proposing a polimerizacion mechanism. This methodology could be promising in the development of a new lignin-based polymer and would open a new direction for the environmental management of the macroalgae on the Mexican beaches.


Assuntos
Clorófitas/enzimologia , Química Verde/métodos , Lacase/química , Lignina/síntese química , Polimerização , Alga Marinha/química , Lignina/química , Peso Molecular , Fenóis/química
11.
World J Microbiol Biotechnol ; 36(3): 51, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157408

RESUMO

Culture-independent molecular-based approaches can be used to identify genes of interest from environmental sources that have desirable properties such as thermo activity. For this study, a putative thermo stable endoglucanase gene was identified from a mixed culture resulting from the inoculation of Brock-CMcellulose (1%) broth with mudspring water from Mt. Makiling, Laguna, Philippines that had been incubated at 90 °C. Genomic DNA was extracted from the cellulose-enriched mixed culture and endo1949 forward and reverse primers were used to amplify the endoglucanase gene, which was cloned into pCR-script plasmid vector. Blastn alignment of the sequenced insert revealed 99.69% similarity to the glycosyl hydrolase, sso1354 (CelA1; Q97YG7) from Saccharolobus solfataricus. The endoglucanase gene (GenBank accession number MK984682) was determined to be 1,021 nucleotide bases in length, corresponding to 333 amino acids with a molecular mass of ~ 37 kDa. The endoglucanase gene was inserted into a pET21 vector and transformed in E. coli BL21 for expression. Partially purified recombinant Mt. Makiling endoglucanase (MM-Engl) showed a specific activity of 187.61 U/mg and demonstrated heat stability up to 80 °C. The thermo-acid stable endoglucanase can be used in a supplementary hydrolysis step to further hydrolyze the lignocellulosic materials that were previously treated under high temperature-dilute acid conditions, thereby enhancing the release of more glucose sugars for bioethanol production.


Assuntos
Celulase/genética , Celulase/metabolismo , Celulose/metabolismo , DNA , Genômica , Água/metabolismo , Sequência de Aminoácidos , Archaea/enzimologia , Archaea/genética , Bactérias/enzimologia , Bactérias/genética , Sequência de Bases , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Peso Molecular , Filipinas , Proteínas Recombinantes , Alinhamento de Sequência , Sulfolobales/enzimologia , Sulfolobales/genética , Temperatura , Microbiologia da Água
12.
Food Chem ; 318: 126477, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32126465

RESUMO

Water-extractable arabinoxylan (WEAX) could effectively improve the cereal food quality, while its regulatory effect on wheat starch properties has yet to be well-understood. This study selected the WEAX with different molecular weight (Mw) but same branched degree, and comparatively investigated their effects on the gelatinization and retrogradation behavior of wheat starch. The decreased degree of swelling power, solubility and peak viscosity suggested that low Mw WEAX (L-WEAX) could hinder starch gelatinization more evidently compared with high Mw WEAX (H-WEAX), due to the pronounced inhibition effect on amylose leaching and amylose-lipid complex formation. L-WEAX suppressed the recrystallization of amylose and thus the short-term retrogradation. However, H-WEAX mainly retarded the recrystallization of amylopectin, exerting a more significant inhibition effect on the long-term retrogradation. This study could provide a theoretical basis for enhancing the quality and extending the shelf life of starchy foods by selecting the optimum structure of WEAX.


Assuntos
Amido/química , Triticum/química , Xilanos/isolamento & purificação , Amilopectina/química , Amilose/química , Varredura Diferencial de Calorimetria , Cristalização , Gelatina/química , Microscopia Confocal , Peso Molecular , Viscosidade , Água/química , Difração de Raios X , Xilanos/química , alfa-Amilases/química , alfa-Amilases/metabolismo
13.
Food Chem ; 318: 126485, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32135424

RESUMO

Type 3 resistant starch (RS3) was developed from native pea starch through acid thinning, debranching and recrystallization, and the resultant pea RS3 was then characterized and compared with that generated from native normal maize starch. Starting from the respective native starches, the modification method yielded 68.1% of RS3 from pea and 59.6% from normal maize. The particles of pea and normal maize RS3 showed a coarse surface and irregular shapes and sizes. Both pea and normal maize RS3 displayed the B-type X-ray diffraction pattern, with 41.0% and 37.7% relative crystallinity, respectively. In vitro starch digestibility assay revealed that pea RS3 - in both uncooked and cooked states - was less digestible by amylolytic enzymes than normal maize RS3 because the former possessed double-helical crystallites of a more compact structure. The information presented in the study is valuable for the development of RS ingredient from pea starch for food applications.


Assuntos
Ervilhas/química , Amido/química , Zea mays/química , Digestão , Manipulação de Alimentos , Temperatura Alta , Peso Molecular , Amido/metabolismo , Difração de Raios X
14.
PLoS One ; 15(3): e0230033, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32150580

RESUMO

Therapy regimens for Chronic lymphocytic leukemia (CLL) commonly include chemotherapy and immunotherapy, which act through complement-mediated-cytotoxicity (CDC) and other mechanisms. CDC depends on several factors, including the availability and activity of the complement classical pathway (CP). Recently, a significant decrease in CP activity was shown to be associated with an immunoglobulin-C5a complex (Ig-C5a) and other markers of chronic CP activation in 40% of the patients. The study focused on the involvement of IgG-hexamers, an established CP activator, in the mechanism of chronic CP activation in CLL. Sera from 51 naïve CLL patients and 20 normal controls were collected. CP and alternative pathway (AP) activities were followed by the complement activity marker sC5b-9. Serum high molecular weight (HMW) proteins were collected by gel-filtration chromatography and their complement activation capacity was assessed. The levels of IgM, another established CP activator, were measured. Data were associated with the presence of Ig-C5a. Baseline levels of activation markers negatively correlated with CP and the AP activities, supporting chronic complement activation. In patients with Ig-C5a, HMW proteins that are not IgM, activated the complement. HMW proteins were identified as IgG-aggregates by affinity binding assays and Western blot analysis. The data indicate chronic CP activation, mediated by cell-free IgG-hexamers as a cause of decreased CP activity in part of the CLL population. This mechanism may affect immunotherapy outcomes due to compromised CP activity and CDC.


Assuntos
Via Clássica do Complemento , Imunoglobulina G/sangue , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/imunologia , Idoso , Feminino , Humanos , Imunoglobulina G/química , Masculino , Pessoa de Meia-Idade , Peso Molecular
15.
Biochim Biophys Acta Bioenerg ; 1861(7): 148192, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32194061

RESUMO

Mutations of many PDSS and COQ genes are associated with primary coenzyme Q10 (CoQ10) deficiency, whereas mitochondrial DNA (mtDNA) mutations might cause secondary CoQ10 deficiency. Previously, we found that COQ5 and COQ9 proteins are present in different protein complexes in the mitochondria in human 143B cells and demonstrated that COQ5 and COQ9 knockdown suppresses CoQ10 levels. In the present study, we characterized other PDSS and COQ proteins and examined possible crosstalk among various PDSS and COQ proteins. Specific antibodies and mitochondrial localization of mature proteins for these proteins, except PDSS1 and COQ2, were identified. Multiple isoforms of PDSS2 and COQ3 were observed. Moreover, PDSS1, PDSS2, and COQ3 played more important roles in maintaining the stability of the other proteins. Protein complexes containing PDSS2, COQ3, COQ4, COQ6, or COQ7 protein in the mitochondria were detected. Two distinct PDSS2-containing protein complexes could be identified. Transient knockdown of these genes, except COQ6 and COQ8, decreased CoQ10 levels, but only COQ7 knockdown hampered mitochondrial respiration and caused increased ubiquinol:ubiquinone ratios and accumulation of a putative biosynthetic intermediate with reversible redox property as CoQ10. Furthermore, suppressed levels of PDSS2 and various COQ proteins (except COQ3 and COQ8A) were found in cybrids containing the pathogenic mtDNA A8344G mutation or in FCCP-treated 143B cells, which was similar to our previous findings for COQ5. These novel findings may prompt the elucidation of the putative CoQ synthome in human cells and the understanding of these PDSS and COQ protein under physiological and pathological conditions.


Assuntos
Alquil e Aril Transferases/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Ubiquinona/análogos & derivados , Especificidade de Anticorpos , Vias Biossintéticas , Linhagem Celular Tumoral , Transporte de Elétrons , Humanos , Peso Molecular , Estabilidade Proteica , Transporte Proteico , Ubiquinona/metabolismo
16.
Chemosphere ; 252: 126559, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32220721

RESUMO

In this study, fluorescent dissolved organic matter (FDOM) in real printing and dyeing wastewater (PDW) during full-scale two-stage treatment was characterized using excitation-emission matrix (EEM), apparent molecular weight (AMW) cutoff by centrifugal ultrafiltration and high-performance liquid chromatography with fluorescence detector (HPLC-FLD). EEMs of PDW during treatment were relatively invariable with two typical and dominant peaks (P1, 275/320 nm and P2, 230/340 nm). The removal rates of P1 intensity and P2 intensity were both lower than those of DOC or UVA254 during the 1st stage and 2nd stage treatment. The <3 kDa fraction made major contribution to DOC, UVA254, P1 and P2 intensity. The DOM fractions with different AMW exhibited different removal behaviors during the 1st stage and 2nd stage treatment. The <3 kDa fraction of FDOM was poorly removed by biological treatment alone. The HPLC-FLD multi-emission scan results indicated that the major part of FDOM clusters were hydrophilic and they were more difficult to remove than the transphilic and hydrophobic FDOM clusters. According to the physicochemical properties of FDOM in PDW, selective adsorption and advanced oxidation process could be prior options for PDW advanced treatment.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Adsorção , Cromatografia Líquida de Alta Pressão , Corantes , Substâncias Húmicas/análise , Interações Hidrofóbicas e Hidrofílicas , Peso Molecular , Impressão Tridimensional , Espectrometria de Fluorescência/métodos , Águas Residuárias/química
17.
Food Chem ; 320: 126631, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32222660

RESUMO

Effect of superfine grinding on pectin extraction was investigated. Sunflower heads were grinded into microparticles of ~50 µm, thus pectin chains were fully exposed due to cell wall breakdown. A good pectin yield of 14.5 ± 0.36% (w/w) was subsequently achieved at mild conditions (pH 5.0, 25 °C, 2 h) associated with 0.8% (w/v) sodium citrate (SC). However, the molecule weight of pectin was greatly reduced (Mw = 7.87 ± 0.21 kDa) due to the action of endo-pectinases. With heating (pH 5.0, 85 °C for 20 min, 25 °C for 1.5 h) the endo-pectinases were effectively inhibited, thus Mw was increased to 338.07 ± 12.37 kDa. With superfine grinding, pectin extracted with different conditions presented various properties. Pectin extracted at pH 2.5 had higher esterification degree (DE, ~40%) and gelled at 3% (w/v) concentration. In contrast, pectin extracted under mild condition with low DE (21%) cannot gel at the same concentration. Conclusively, superfine grinding has potential application in pectin extraction.


Assuntos
Helianthus/química , Pectinas/química , Esterificação , Temperatura Alta , Peso Molecular , Pectinas/isolamento & purificação
18.
Food Chem ; 320: 126647, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32220708

RESUMO

In this study, three-phase partitioning (TPP) coupled with gradient ammonium sulfate ((NH4)2SO4) precipitation (GNP) method was first used to extract and separate bioactive polysaccharides (OPSs) from fresh okra pods. Results showed that OPS-50 obtained by GNP at a saturation of 50% (NH4)2SO4 after TPP presented higher precipitation yield, carbohydrate (86.82%) and uronic acid (22.34%) contents with same monosaccharide composition and different molar ratios compared with OPS-30 and OPS-40 obtained via GNP at saturations of 30% and 40% (NH4)2SO4, respectively. OPS-50 had lower weight-average molecular weight (3.65 × 106 g/mol), more flexible chain, and relatively looser surface structure compared with OPS-30, OPS-40, and the OPS obtained with TPP parallelized with decreased apparent viscosity and dynamic viscoelasticity. Furthermore, OPS-50 exhibited stronger DPPH radical-scavenging ability, antioxidant capacity, and α-amylase and α-glucosidase inhibitory activities in vitro than OPS, OPS-30, and OPS-40.


Assuntos
Abelmoschus/química , Polissacarídeos/química , Antioxidantes/química , Carboidratos/química , Fenômenos Químicos , Peso Molecular
19.
Int J Nanomedicine ; 15: 483-495, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32158206

RESUMO

Background: The complex preparation procedures and severe toxicities are two major obstacles facing the wide use of chimeric antigen receptor-modified T (CAR-T) cells in clinical cancer immunotherapy. The nanotechnology-based T cell temporary CAR modification may be a potential approach to solve these problems and make the CAR-T cell-based tumor therapy feasible and broadly applicable. Methods: A series of plasmid DNA-loaded self-assembled nanoparticles (pDNA@SNPsx/y) prepared from adamantane-grafted polyamidoamine (Ad-PAMAM) dendrimers of different generations (G1 or G5) and cyclodextrin-grafted branched polyethylenimine (CD-PEI) of different molecular weights (800, 2000, or 25,000 Da) were characterized and evaluated. The detailed physicochemical properties, cellular interaction, and cytotoxicity of selected pDNA@SNPG1/800 were systematically investigated. Thereafter, the epidermal growth factor receptor variant III (EGFRvIII) CAR-expression plasmid vector (pEGFRvIII-CAR) was constructed and encapsulated into SNPG1/800. The resulting pEGFRvIII-CAR@SNPG1/800 was used for Jurkat cell transient transfection, and the EGFRvIII-CAR expressed in transfected cells was measured by flow cytometry and Western blot. Finally, the response of EGFRvIII CAR-positive Jurkat T cell to target tumor cell was evaluated. Results: The pDNA@SNPG1/800 showed the highest efficacy in Jurkat cell gene transfection and exhibited low cytotoxicity. pEGFRvIII-CAR@SNPG1/800 can efficiently deliver pEGFRvIII-CAR into Jurkat T cells, thereby resulting in transient EGFRvIII-CAR expression in transfected cells. EGFRvIII-CAR that is present on the cell membrane enabled Jurkat T cells to recognize and bind specifically with EGFRvIII-positive tumor cells. Conclusion: These results indicated that pEGFRvIII-CAR@SNPG1/800 can effectively achieve T-cell transient CAR modification, thereby demonstrating considerable potential in CAR-T cancer therapy.


Assuntos
Receptores ErbB/genética , Técnicas de Transferência de Genes , Imunoterapia Adotiva/métodos , Nanopartículas/química , Linfócitos T/fisiologia , Linhagem Celular Tumoral , Dendrímeros/química , Vetores Genéticos , Humanos , Iminas/química , Imunoterapia , Células Jurkat , Peso Molecular , Polietilenos/química , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/genética , Transfecção/métodos
20.
J Chromatogr A ; 1621: 461029, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32192704

RESUMO

The aim of the present study was to compare the enantioseparation performance of chiral stationary phases (CSPs) which were derived from chitosans of different sources and molecular weights. Therefore, chitosans of shrimp and crab shells were prepared. The viscosity-average molecular weights of the chitosans both prepared from shrimp and crab shells were 2.8 × 105 and 1.4 × 105. The chitosans were isobutyrylated yielding isopropylcarbonyl chitosans which were then derivatized with 4-methylphenyl isocyanate to provide chitosan 3,6-bis(4-methylphenylcarbamate)-2-(isobutyrylamide)s. The chitosan 3,6-bis(4-methylphenylcarbamate)-2-(isobutyrylamide)s were used as chiral selectors (CSs) with which the corresponding CSPs were prepared. With the same chiral analytes and under the same mobile phase conditions, the enantioseparation capability of the CSPs was evaluated by high-performance liquid chromatography. In two CSs prepared from the same source, the one with higher molecular weight showed better enantioseparation capability; in two CSs prepared with the chitosans of the same molecular weight, the one derived from shrimp shell exhibited better performance. With regard to the two shrimp chitosan CSs, most of chiral analytes interacted more strongly with the one with lower molecular weight, and an opposite trend was found for the two crab chitosan CSs. Based on the results observed in the present study and in previous work, we believe that the influence of molecular weight on CSP enantioseparation performance is related to the substituent introduced in the CS molecule.


Assuntos
Quitosana/química , Cromatografia Líquida de Alta Pressão , Animais , Braquiúros/química , Quitosana/análogos & derivados , Peso Molecular , Penaeidae/química , Estereoisomerismo
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