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1.
Mikrochim Acta ; 188(3): 101, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33630138

RESUMO

Green emitting copper nanoclusters (G-Cu NCs), yellow emitting Cu NCs (Y-Cu NCs), orange emitting Cu NCs (O-Cu NCs) and red emitting Cu NCs (R-Cu NCs) were prepared using chicken egg white as the stabilizer by changing the reaction conditions. This is a green, facile and cheap method to explore different color emitting CuNCs by the same precursor and stabilizers. The G-Cu NCs were employed for the detection of ethanol due to their aggregation induced emission enhancement (AIEE) effect. The fluorescence emission of Cu NCs at 526 nm under the excitation of 444 nm can be effectively enhanced in the presence of ethanol due to AIEE effect, thus realizing the quantitative determination of ethanol content in the range 5-60%. In addition, a visual dual-emission fluorescence probe with the combination of G-Cu NCs and silicon nanoparticles (Si NPs/G-Cu NCs) was designed to evaluate ethanol content conveniently and rapidly. Desirable linear relationship is observed between ratio of fluorescence intensity (I525/I441) and ethanol content under the excitation of 383 nm. Visible color transformation of this probe is observed in the ethanol content range 2-20%. Moreover, the ethanol sensing platforms were applied to the detection and evaluation of the alcohol content of liquor, and the recoveries in liquor were in the range 99.7% to 113%, broadening the applications of Cu NCs and providing a sensitive detection method for ethanol.


Assuntos
Conalbumina/química , Etanol/análise , Corantes Fluorescentes/química , Nanopartículas Metálicas/química , Muramidase/química , Ovalbumina/química , Animais , Proteínas Aviárias/química , Galinhas , Cobre/química , Bebidas Fermentadas/análise , Fluorescência , Limite de Detecção , Espectrometria de Fluorescência/métodos
2.
Mikrochim Acta ; 188(1): 15, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398483

RESUMO

A dual-channel "naked-eye" colorimetric and ratio fluorescent probe has been developed based on titanium carbide quantum dots for the detection of curcumin and hypochlorite (ClO-). The fluorescence emission of Ti3C2 MXene quantum dots (Ti3C2 MQDs) is in the range 350-600 nm, and the maximum emission peak is at 430 nm that overlaps with the UV absorption of curcumin at 430 nm to a large extent. This facilitates the fluorescence resonance energy transfer (FRET) between Ti3C2 MQDs and curcumin. When ClO- is added, the phenolic and methoxy groups of curcumin are oxidized to quinones, resulting in the restoration of the fluorescence of Ti3C2 MQD. In addition, the probe designed makes it easier to distinguish colors with the naked eye to detect curcumin and ClO-. The linear detection range of curcumin was 0.05-10 µM, and the detection limit was 20 nM. The linear detection ranges of ClO- are 25-150 µM and 150-275 µM, and the detection limit is 5 µM. This study is the first report on the determination of curcumin and ClO- based on Ti3C2 MQDs by dual-channel "naked-eye" colorimetric and ratio fluorescence method.

3.
J Environ Manage ; 294: 113026, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34119990

RESUMO

High cost is one of the limiting factors in the industrial production of bioflocculant. Simultaneous preparation of bioflocculant from the contaminants in wastewater was considered as a potential approach to reduce the production cost. In this study, caprolactam was verified as sole feedstock for the growth of strain Alcaligenes faecalis subsp. phenolicus ZY-16 in batch experiments. Chemical analysis showed that the as-prepared MBF-16 consisted of heteropolysaccharides (88.3%) and peptides (9.4%). XPS result indicated the plentiful acylamino, hydroxyl and amino groups in MBF-16, which have an indispensable role in amoxicillin flocculation. The flocculation of amoxicillin can be well stimulated by Freundlich isotherm equation, and the Kf was up to 178.6524 for amoxicillin. The kinetic fitting results proved that the flocculation of amoxicillin by MBF-16 was chemisorbed. This contribution may develop a novel technology for the preparation of bacterial flocculants that can consume toxic substrates (caprolactam) and have potential applications in amoxicillin removal.


Assuntos
Caprolactama , Alcaligenes , Amoxicilina , Floculação , Concentração de Íons de Hidrogênio , Águas Residuárias
4.
J Fluoresc ; 29(3): 719-726, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31093827

RESUMO

We fabricated a new and selective fluorescent sensor for the detection of citrate by employing g-C3N4 quantum dots (g-CNQDs) and MgFe layered double hydroxide (MgFe-LDH). The g-CNQDs interacted with MgFe-LDH via electrostatic interaction and the fluorescence of g-CNQDs was effectively quenched by MgFe-LDH due to inner filter effect. Upon addition of citrate, the fluorescence of the g-CNQDs was significantly enhanced, arising from the replacement of g-CNQDs by citrate because citrate competed with g-CNQDs to form more stable complexes with MgFe-LDH. Therefore, we developed a "turn-off-on" fluorescence assay method for the detection of citrate. This method enabled the selective detection of citrate with linear range of 0.5-3.0 µM and 3.0-10.0 µM with a 12.3 nM limit of detection. This method exhibited advantages including easy preparation, environmentally friendly process and rapid response toward citrate.

5.
Mikrochim Acta ; 186(12): 770, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31713685

RESUMO

Titanium carbide quantum dots functionalized with ε-poly-L-lysine (PLL) were synthesized by sonication cutting and hydrothermal synthesis. The deprotonated Ti3C2 MXene quantum dots (Ti3C2 MQDs) exhibit excitation wavelength-dependent blue photoluminescence with typical excitation/emission peaks at 330/415 nm and a quantum yield of 22% due to strong quantum confinement. The fluorescence of ε-poly-L-lysine protected Ti3C2 MQDs (PLL-protected Ti3C2 MQDs) is reduced via an inner filter effect after the addition of cytochrome c (cyt-c). Response to cyt-c is linear in the 0.2 to 40 µM concentration range and the detection limit is 20.5 nM. In the presence of trypsin, cyt-c is hydrolyzed to small peptides, and the Fe3+ ion in cyt-c probably is reduced to Fe2+ with the aid of the digestive enzyme. This results in the restoration of the blue fluorescence of the modified MQDs. Fluorescence increases linearly in the 0.5 to 80 µg mL-1 trypsin concentration range with the detection limit of 0.1 µg mL-1. The method was successfully applied to the determination of cyt-c and trypsin in spiked serum samples. Graphical abstractSchematic of a method for the fluorometric "turn-off-on" determination of cytochrome c and trypsin based on ε-poly-L-lysine (PLL) protect MXene quantum dots (Ti3C2 MQDs).


Assuntos
Citocromos c/análise , Fluorometria , Polilisina/química , Pontos Quânticos/química , Titânio/química , Tripsina/análise , Citocromos c/metabolismo , Corantes Fluorescentes/química , Tamanho da Partícula , Teoria Quântica , Propriedades de Superfície , Tripsina/metabolismo
6.
Mikrochim Acta ; 186(8): 585, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363918

RESUMO

Nitrogen and chlorine dually-doped carbon dots (N,Cl-CDs) were hydrothermally prepared starting from 4-chloro-1,2-diaminobenzene and dopamine. The N,Cl-CDs exhibit strong orange fluorescence, with excitation/emission maxima at 420/570 nm and a relative high quantum yield (15%). The N,Cl-CDs were employed to detect acetylcholinesterase (AChE) activity and organophosphate pesticides (OPs) which are enzyme inhibitors. Acetylthiocholine is enzymatically split by AChE to produce thiocholine which triggers the decomposition of Ellmans's reagent to form a yellow colored product (2-nitro-5-thiobenzoate anion). The product causes an inner filter effect (IEF) on the fluorescence of the N,Cl-CDs. Fluorescence decreases linearly in the 0.017 to 5.0 Unit·L-1 AChE activity range, and the detection limit is 2 mUnit·L-1. If organophosphates are present, the activity of AChE becomes increasingly blocked, and this leads to a less expressed IFE and an increasing recovery of fluorescence. This was used for the quantification of OPs. Response is linear in the 0.3-1000 µg·L-1 OP concentration range with a 30 ng·L-1 detection limit. Graphical abstractSchematic representation of the synthesis of nitrogen and chlorine dually-doped carbon dots (N,Cl-CDs) and the recognition of organophosphate pesticides by N,Cl-CDs.


Assuntos
Acetilcolinesterase/química , Carbono/química , Inseticidas/análise , Organofosfatos/análise , Poluentes do Solo/análise , Cloro/química , Fluorometria , Inseticidas/química , Nitrogênio/química , Organofosfatos/química , Poluentes do Solo/química
7.
Mikrochim Acta ; 185(7): 332, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29926199

RESUMO

A composite (Ag-g-CNQDs) was prepared from graphitic carbon nitride quantum dots and silver nanoparticles by water phase synthesis. Aided by metal-enhanced fluorescence, the composite exhibits excitation-dependent red emission with a peak at 600 nm with a quantum yield of 21%. If the composite is coated with polyethylenimine (PEI) to form the Ag-g-CNQD/PEI complexe, fluorescence is strongly reduced. Upon addition of heparin, the fluorescence of the system is enhanced because PEI has a higher affinity for heparin than Ag-g-CNQDs. The effect was used to design a fluorometric  assay for heparin. The emission at 600 nm increases linearly in the 0.025 to 2.5 µM heparin concentration range, with a 8.2 nM limit of detection. Graphical abstract Schematic illustration for fabricating a composite consisting of silver nanoparticles and graphitic carbon nitride quantum dots (Ag-g-CNQDs). Its red fluorescence is weak in presence of polyethyleneimine but restored on addition of heparin. This forms the basis for a new method for heparin detection.


Assuntos
Grafite/química , Heparina/análise , Limite de Detecção , Nanopartículas Metálicas/química , Nitrilas/química , Pontos Quânticos/química , Prata/química , Heparina/sangue , Heparina/química , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Polietilenoimina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
8.
Mikrochim Acta ; 186(1): 5, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30535645

RESUMO

A rapid method is described for synthesis of copper nanoclusters (CuNCs) by utilizing L-histidine as the stabilizer and ascorbic acid (AA) as the reductant. The CuNCs display blue-green fluorescence with excitation/emission peaks at 390/485 nm. A sensitive fluorometric assay was worked out for determination of alkaline phosphatase (ALP) activity. If the ALP substrate p-nitrophenylphosphate (PNPP) is enzymatically hydrolyzed, it forms p-nitrophenol (PNP) which reduces the fluorescence of CuNCs because its absorption band at 410 nm overlaps the excitation peak of CuNCs at 390 nm. In addition, the amino groups and imidazole groups on the surface of CuNCs possibly form a complex with the phenol groups of PNP. This induces aggregation-induced quenching of the fluorescence of CuNCs. The fluorescent probe has a linear analytical range that extends from 0.5 mU·mL-1 to 40 mU·mL-1 and a detection limit of 45 µU·mL-1. Graphical abstract Schematic illustration of a fluorometric assay for alkaline phosphatase (ALP) activity that uses L-histidine protected copper nanoclusters (CuNCs), aggregation-induced quenching, and the inner filter effect between PNP and CuNCs.

9.
Mikrochim Acta ; 185(8): 383, 2018 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-30032328

RESUMO

Stable copper nanoclusters (CuNCs) were prepared by utilizing D-penicillamine as both the stabilizer and reductant. The emission of the CuNCs (with excitation/emission peaks at 390/645 nm) is largely stabilized by coating with poly(sodium-p-styrenesulfonate) (PSS). Cytochrome c (Cyt c) quenches the fluorescence of the PSS-coated CuNCs, and this effect was exploited to design a quenchometric fluorometric assay for Cyt c. If trypsin is added to the loaded CuNCs, it will hydrolyze Cyt c to form peptide fragments, and fluorescence is gradually restored. A highly sensitive and fluorometric turn-off-on assay was constructed for sequential detection of Cyt c and trypsin. The linear ranges for Cyt c and trypsin are from 8.0 nM to 680 nM, and from 0.1 to 6.0 µg mL-1, and the lower detection limits are 0.83 nM and 20 ng mL-1 for Cyt c and trypsin, respectively. Graphical abstract Schematic illustration of the fluorometric assay for trypsin based on the electron transfer between poly(p-styrenesulfonate)-protected copper nanoclusters (PSS-CuNCs) and cytochrome c (Cyt c).


Assuntos
Cobre/química , Citocromos c/análise , Corantes Fluorescentes/química , Fluorometria/métodos , Nanopartículas Metálicas/química , Poliestirenos/química , Tripsina/análise , Animais , Citocromos c/química , Humanos , Hidrólise , Modelos Moleculares , Conformação Proteica , Fatores de Tempo , Tripsina/química
10.
Mikrochim Acta ; 185(1): 17, 2017 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29594532

RESUMO

Boron and nitrogen codoped carbon dots functionalized with cyclodextrin (ß-CD-N/B-C-dots) were obtained from ß-cyclodextrin. The material displays strong fluorescence (with excitation/emission peak wavelengths of 400/500 nm) and was characterized by UV-vis, transmission electron microscopy and FTIR. If the substrate p-nitrophenylphosphate is enzymatically cleaved by alkaline phosphatase (ALP), a yellow product is formed whose absorption overlaps the excitation spectrum of the ß-CD-N/B-C-dots. Hence, fluorescence is reduced due to an inner filter effect. In additon, the ß-CD cavity offers a pocket for substrate recognition. The findings were used to design a method for the determination of the activity of ALP. It has a working range that extends from 0.003 to 5.5 U·L-1, with a 0.3 mU·L-1 detection limit. The method is fast, simple, inexpensive, and highly sensitive and selective. Graphical abstract Schematic of an inner filter effect based probe for alkaline phosphatase based on the use boron and nitrogen co-doped carbon dots (N/B-C-dots) modified with ß-cyclodextrin (ß-CD). PNPP: p-Nitrophenylphosphate; PNP: p-Nitrophenol anion.


Assuntos
Fosfatase Alcalina/metabolismo , Boro/química , Carbono/química , Ensaios Enzimáticos/métodos , Fluorometria/métodos , Nitrogênio/química , Pontos Quânticos/química , Filtração
11.
Tumour Biol ; 37(3): 3561-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26456956

RESUMO

Increasing evidence indicates that abnormal microRNA (miRNA) expression is related to hepatocellular carcinoma (HCC) development. Our study aimed to elucidate the essential role of miR-329 in HCC progression. Real-time PCR was used to analyze miR-329 and bromodomain containing 4 (BRD4) expression in HCC samples (n = 135). Cell Counting Kit-8 (CCK-8) and flow cytometric analysis were used to investigate cell proliferation and apoptosis. The transwell assay was used to examine the cell invasive ability. The regulation mechanism was confirmed by luciferase reporter and western blot assays. Kaplan-Meier analysis was used to detect the function of miR-329 on the prognosis of HCC patients. miR-329 was decreased in HCC samples and was related to tumor development. Furthermore, miR-329 significantly regulated cell invasion by targeting BRD4 but had no effect on cell proliferation and apoptosis. Moreover, downregulation of miR-329 predicted poor prognosis of HCC patients. miR-329 could control cell invasion via regulating BRD4 expression and may be a prognostic marker in HCC.


Assuntos
Carcinoma Hepatocelular/genética , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , MicroRNAs/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Apoptose/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Citometria de Fluxo , Células Hep G2 , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Invasividade Neoplásica , Proteínas Nucleares/metabolismo , Valor Preditivo dos Testes , Prognóstico , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/metabolismo
12.
Tumour Biol ; 37(4): 5515-20, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26572149

RESUMO

miR-25 was identified as an essential oncogene by promoting the growth and metastasis through TOB1 in gastric cancer (GC). The function of the single nucleotide polymorphism (SNP) located in the mature region of miR-25 (rs41274221) has not been investigated. In this study, we aimed to explore the involvement of rs41274221 in miR-25 in gastric cancer. We found that SNP rs41274221 in miR-25 was participated in the occurrence of GC by acting as a tumor protective factor associating with the tumor growth and metastasis. Besides, further investigation found that upregulation of miR-25 with AA genotype could attenuate the proliferation and invasion of tumor cells caused by wild-type miR-25. The dual-luciferase reporter assay also confirmed that miR-25 harbored the A allele which caused an incapacitation of binding at the TOB1. In conclusion, rs41274221 in miR-25 was a subgroup which may protect the patients from further growth and metastasis of gastric cancer and might serve as a novel biomarker for the disease.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Proteínas Supressoras de Tumor/genética , Adulto , Alelos , Carcinogênese , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Polimorfismo de Nucleotídeo Único , Transdução de Sinais , Neoplasias Gástricas/patologia
13.
J Environ Manage ; 172: 71-6, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26921567

RESUMO

A novel bioflocculant (MBF-79) prepared using formaldehyde wastewater as carbon resource was investigated in the study. The optimal conditions for bioflocculant production were determined to be an inoculum size of 7.0%, initial pH of 6.0, and formaldehyde concentration of 350 mg/L. An MBF-79 of 8.97 g/L was achieved as the maximum yield. Three main elements, namely C, H, and O, were present in MBF-79 with relative weigh percentages of 39.17%, 6.74%, and 34.55%, respectively. The Gel permeation chromatography analysis indicated that the approximate molecular weight (MW) of MBF-79 was 230 kDa. MBF-79 primarily comprised polysaccharide (71.2%) and protein (27.9%). Additionally, conditions for the removal of arsenic by MBF-79 were found to be MBF-79 at 120 mg/L, an initial pH 7.0, and a contact time 60 min. Under the optimal conditions, the removal efficiencies of arsenate (0.5 mg/L) and arsenite (0.5 mg/L) were 98.9% and 84.6%, respectively. Overall, these findings indicate bioflocculation offers an effective alternative method of decreasing arsenic during water treatment.


Assuntos
Arsênio/isolamento & purificação , Formaldeído/química , Águas Residuárias/microbiologia , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Arseniatos/isolamento & purificação , Arsênio/química , Arsenitos/isolamento & purificação , Carbono/metabolismo , Floculação , Concentração de Íons de Hidrogênio , Esgotos/microbiologia , Águas Residuárias/química
14.
Water Sci Technol ; 73(4): 707-15, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26901711

RESUMO

A novel bioflocculant MBF057 produced by a salt-tolerant Haloplanus vescus HW0579 was investigated in this study. The effects of culture conditions such as initial pH, inoculum size, and chemical oxygen demand (COD) of K-acid wastewater on MBF0579 production were studied. The result showed that 8.09 g/L purified MBF0579 was extracted with the following optimized conditions: 780 mg/L COD of K-acid wastewater as carbon source, inoculum size 12.5%, and initial pH 7.0. The biopolymer contained 78.6% polysaccharides and 21.1% proteins. The highest flocculating rate of 81.86 and 95.07% for the COD and chroma of acid brilliant scarlet gelb rot (yellow/red, GR) dye wastewater were achieved at a dosage of 150 mg/L, pH 2.0 and contact time 100 min. Overall, these findings indicate bioflocculation offers an effective alternative method of decreasing acid brilliant scarlet GR during dye wastewater treatment.


Assuntos
Corantes/metabolismo , Recuperação e Remediação Ambiental/métodos , Euryarchaeota/metabolismo , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Compostos Azo/metabolismo , Benzenossulfonatos/metabolismo , Biodegradação Ambiental , Floculação , Concentração de Íons de Hidrogênio , Águas Residuárias/química , Águas Residuárias/microbiologia
15.
Int J Biol Macromol ; 256(Pt 2): 128497, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38035966

RESUMO

Cellulose composite nanopaper is extensively employed in flexible energy storage systems owing to their light weight, good flexibility and high specific surface area. Nevertheless, achieving flexible and ultrathin nanopaper supercapacitors with excellent electrochemical performance remains a challenge. Herein, surface cationization of bacterial cellulose (BC) nanofibers was conducted using 2,3-epoxypropyltrimethylammonium chloride (EPTMAC). Anion-doped polypyrrole (PPy) was incorporated onto the surface of the cationic bacterial cellulose (BCE) nanofibers by an interfacial electrostatic self-assembly process. The obtained PPy@BCE electrode exhibited excellent electrochemical performance, including an areal capacitance of 3988 mF cm-2 at 1.0 mA cm-2 and a capacitance retention of 97 % after 10,000 cycles. A laminated paper-forming strategy was adopted to design and fabricate all-in-one integrated flexible supercapacitors (IFSCs) using PPy@BCE nanopaper as electrodes and BC nanopaper as a separator. The IFSCs showed superior areal capacitance (3669 mF cm-2 at 1 mA cm-2), high energy density (193.7 µWh cm-2 at a power density of 827.3 µW cm-2), and outstanding mechanical flexibility (with no significant capacitance attenuation after repeatedly bending for 1000 times). The present strategy paves a way for the large-scale production of paper-based energy storage devices.


Assuntos
Araceae , Celulose , Polímeros , Pirróis , Cátions
16.
Int J Biol Macromol ; 268(Pt 1): 131622, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38636762

RESUMO

Separator is an essential component of lithium-ion batteries (LIBs), which is placed between the electrodes to impede their electrical contact and provide the transport channels for lithium ions. Traditionally, the separator contributes the overall mass of LIBs, thereby reducing the gravimetric capacity of the devices. Herein, a dual-layer redox-active cellulose separator is designed and fabricated to enhance the electrochemical performances of LIBs by introducing NiS. The presented separator is composed of an insulating bacterial cellulose (BC) nanofiber layer and a conductive, and redox-active NiS@BC/carbon nanotubes layer. By using the NiS@BC separator, the discharge capacity of the LiFePO4//Li half battery is enhanced to 117 mAh g-1 at a current of 2C owing to the redox-activity of NiS. Moreover, the functional separator-electrode interface can facilitate the homogenous Li stripping/plating and depress the polarization upon the repeated stripping/plating process. Consequently, the battery containing the redox-active separator exhibits outstanding cycle stability and rate capability. The present study contributes a novel strategy for the developments of functional separators to improve the electrochemical properties of LIBs.


Assuntos
Celulose , Fontes de Energia Elétrica , Eletrodos , Lítio , Nanofibras , Oxirredução , Lítio/química , Nanofibras/química , Celulose/química , Celulose/análogos & derivados , Nanotubos de Carbono/química , Íons/química , Técnicas Eletroquímicas
17.
J Hazard Mater ; 465: 133435, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38224639

RESUMO

Nylon-6,6 microplastics (NMPs) in aquatic systems have emerged as potential contaminants to the global environment and have garnered immense consideration over the years. Unfortunately, there is currently no efficient method available to eliminate NMPs from sewage. This study aims to address this issue by isolating Brucella intermedia ZL-06, a bacterium capable of producing a bacterial polysaccharide-based flocculant (PBF). The PBF generated from this bacterium shows promising efficacy in effectively flocculating NMPs. Subsequently, the precipitated flocs (NMPs + PBF) were utilized as sustainable feedstock for synthesizing PBF. The study yielded 6.91 g/L PBF under optimum conditions. Genome sequencing analysis was conducted to study the mechanisms of PBF synthesis and nylon-6,6 degradation. The PBF exhibited impressive flocculating capacity of 90.1 mg/g of PBF when applied to 0.01 mm NMPs, aided by the presence of Ca2+. FTIR and XPS analysis showed the presence of hydroxyl, carboxyl, and amine groups in PBF. The flocculation performance of PBF conformed to Langmuir isotherm and pseudo-first-order adsorption kinetics model. These findings present a promising approach for reducing the production costs of PBF by utilizing NMPs as sustainable nutrient sources.


Assuntos
Brucella , Caprolactama/análogos & derivados , Microplásticos , Polímeros , Plásticos , Esgotos/microbiologia , Floculação
18.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 37(9): 1055-1061, 2023 Sep 15.
Artigo em Zh | MEDLINE | ID: mdl-37718415

RESUMO

Objective: To investigate the efficacy and safety of multiple-dose intravenous tranexamic acid (TXA) for reducing blood loss in complex tibial plateau fractures with open reduction internal fixation by a prospective randomized controlled trial. Methods: A study was conducted on patients with Schatzker type Ⅳ-Ⅵ tibial plateau fractures admitted between August 2020 and December 2022. Among them, 88 patients met the selection criteria and were included in the study. They were randomly allocated into 3 groups, the control group (28 cases), single-dose TXA group (31 cases), and multiple-dose TXA group (29 cases), using a random number table method. There was no significant difference ( P>0.05) in terms of age, gender, body mass index, the Schatzker type and side of fracture, laboratory examinations [hemoglobin (Hb), activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (Fib), international normalized ratio (INR), D-dimer, and interleukin 6 (IL-6)], and preoperative blood volume. The control group received intravenous infusion of 100 mL saline at 15 minutes before operation and 3, 6, and 24 hours after the first administration. The single-dose TXA group received intravenous infusion of 1 g TXA (dissolved in 100 mL saline) at 15 minutes before operation, followed by an equal amount of saline at each time point after the first administration. The multiple-dose TXA group received intravenous infusion of 1 g TXA (dissolved in 100 mL saline) at each time point. The relevant indicators were recorded and compared between groups to evaluate the effectiveness and safety of TXA, including hospital stays, operation time, occurrence of infection; the occurrence of lower extremity deep vein thrombosis, intermuscular vein thrombosis, and pulmonary embolism at 1 week after operation; the lowest postoperative Hb value and Hb reduction rate, the difference (change value) between pre- and post-operative APTT, PT, Fib, and INR; D-dimer and IL-6 at 24 and 72 hours after operation; total blood loss, intraoperative blood loss, hidden blood loss, drainage flow during 48 hours after operation, and postoperative blood transfusion. Results: ① TXA efficacy evaluation: the lowest Hb value in the control group was significantly lower than that in the other two groups ( P<0.05), and there was no significant difference between the single- and multiple-dose TXA groups ( P>0.05). The Hb reduction rate, total blood loss, intraoperative blood loss, drainage flow during 48 hours after operation, and hidden blood loss showed a gradual decrease trend in the control group, single-dose TXA group, and multiple-dose TXA group. And differences were significant ( P<0.05) in the Hb reduction rate and drainage flow during 48 hours after operation between groups, and the total blood loss and hidden blood loss between control group and other two groups. ② TXA safety evaluation: no lower extremity deep vein thrombosis or pulmonary embolism occurred in the three groups after operation, but 3, 4, and 2 cases of intermuscular vein thrombosis occurred in the control group, single-dose TXA group, and multiple-dose TXA group, respectively, and the differences in the incidences between groups were not significant ( P>0.05). There was no significant difference in the operation time between groups ( P>0.05). But the length of hospital stay was significantly longer in the control group than in the other groups ( P<0.05); there was no significant difference between the single- and multiple-dose TXA groups ( P>0.05). ③ Effect of TXA on blood coagulation and inflammatory response: the incisions of the 3 groups healed by first intention, and no infections occurred. The differences in the changes of APTT, PT, Fib, and INR between groups were not significant ( P>0.05). The D-dimer and IL-6 in the three groups showed a trend of first increasing and then decreasing over time, and there was a significant difference between different time points in the three groups ( P<0.05). At 24 and 72 hours after operation, there was no significant difference in D-dimer between groups ( P>0.05), while there was a significant difference in IL-6 between groups ( P<0.05). Conclusion: Multiple intravenous applications of TXA can reduce perioperative blood loss and shorten hospital stays in patients undergoing open reduction and internal fixation of complex tibial plateau fractures, provide additional fibrinolysis control and ameliorate postoperative inflammatory response.


Assuntos
Trombose , Fraturas da Tíbia , Fraturas do Planalto Tibial , Ácido Tranexâmico , Humanos , Ácido Tranexâmico/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Interleucina-6 , Estudos Prospectivos , Fraturas da Tíbia/cirurgia
19.
Carbohydr Polym ; 300: 120301, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36372499

RESUMO

A major challenge to large-scale production and utilization of bacterial cellulose (BC) for various applications is its low yield and productivity by bacterial cells and the high cost of feedstock. A supplementation of the classical expensive Hestrin and Schramm (HS) medium with 1 % polyethylene terephthalate ammonia hydrolysate (PETAH) resulted in 215 % high yield. Although the physicochemical properties of BC were not significantly influenced, the BC produced in 1 % PETAH-supplemented HS medium showed a higher surface area, which showed 1.39 times higher adsorption capacity for tetracycline than BC produced in HS medium. The 1 % PETAH-supplemented HS medium respectively enhanced the activity of α-UDP-glucose pyrophosphorylase and α-phosphoglucomutase by 30.63 % and 135.24 % and decreased the activity of pyruvate kinase and phosphofructokinase by 40.34 % and 52.63 %. The results of this study provide insights into the activation mechanism of Taonella mepensis by PETAH supplementation for high yield and productivity of BC.


Assuntos
Gluconacetobacter xylinus , Celulose/química , Polietilenotereftalatos , Meios de Cultura/química
20.
RSC Adv ; 12(55): 35666-35675, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36545067

RESUMO

Doxorubicin (DOX) has been an emerging environmental pollutant due to its significant genotoxicity to mankind. Advanced oxidation processes are a potential strategy to remove DOX in water solution. To develop a highly efficient catalytic agent to remove DOX, bimetal MOFs were synthesized, with Cu2+ and Co2+ as the central ions and adenine as the organic ligand. This study investigated the degradation of DOX by Co/Cu-MOFs combined with peroxymonosulfate (PMS). It was found that the degradation of DOX by Co/Cu-MOFs can reach 80% in only 10 seconds. This can be explained by the charge transfer from Co(iii) to Co(ii) being accelerated by Cu2+, resulting in the rapid generation of free radicals, which was proved by the EIS Nyquist diagram. Co/Cu-MOFs can be reused by simply washing with water without inactivation. Therefore, Co/Cu-MOFs can be used as an efficient catalytic agent to degrade DOX in environmental water.

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