Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
1.
Bioresour Technol ; 400: 130679, 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38588781

RESUMO

Mainstream partial denitrification anammox was achieved through inoculation of side-stream mature partial nitritation anammox biofilm without domestication. The contribution of anammox to nitrogen removal was 29.4 %. Moreover, prolonging anoxic hydraulic retention time and introducing side-stream nitrite under different carbon/nitrogen ratios enriched anammox bacteria. The abundance of anammox bacteria increased by âˆ¼ 10 times ((2.19 ± 0.17) × 1012 copies gene / g dry sludge) with a total relative abundance of 18.51 %. During 258 days of operation, the contribution of anammox to nitrogen removal gradually increased to 68.8 %. The total nitrogen in the effluent decreased to 8.84 mg/L with a total nitrogen removal efficiency of 76.4 % under a carbon/nitrogen ratio of 3. This paper proposes a novel way to rapidly achieve mainstream partial denitrification anammox via inoculation with side-stream mature partial nitritation anammox biofilm. This method achieves advanced nitrogen removal from municipal wastewater, even under low carbon/nitrogen ratios.

2.
Neuroreport ; 35(6): 421-430, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38526966

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disease characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra (SN). The main bioactive component of green tea polyphenols (-)-epigallocatechin-3-gallate (EGCG) exerts protective effects against diseases such as neurodegenerative diseases and cancer. Therefore, this study investigated the effect of EGCG on the amelioration of neural damage in a chronic PD mouse model induced by α-synuclein preformed fibrils (α-syn-PFFs). A total of 20 C57BL/6J female mice were randomly divided into 3 groups: control group (saline, n = 6), model group (PFFs, n = 7), and prevention group (EGCG+PFFs, n = 7). A chronic PD mouse model was obtained by the administration of α-syn-PFFs by stereotaxic localization in the striatum. Behavioral tests were performed to evaluate PD-related anxiety-like behavior and motor impairments in the long-term PD progression. Tyrosine hydroxylase (TH) immuno-positive neurons and Ser129-phosphorylated α-syn (p-α-syn) were identified by immunohistochemistry. Pro-inflammatory and anti-inflammatory cytokines were measured by real-time quantitative PCR. EGCG pretreatment reduced anxiety-like behavior and motor impairments as revealed by the long-term behavioral test (2 weeks, 1 month, 3 months, and 6 months) on PD mice. EGCG also ameliorated PFF-induced degeneration of TH immuno-positive neurons and accumulation of p-α-syn in the SN and striatum at 6 months. Additionally, EGCG reduced the expression of pro-inflammatory cytokines while promoting the release of anti-inflammatory cytokines. EGCG exerts a neuroprotective effect on long-term progression of the PD model.


Assuntos
Catequina/análogos & derivados , Doenças Neurodegenerativas , Fármacos Neuroprotetores , Doença de Parkinson , Camundongos , Feminino , Animais , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo , Fármacos Neuroprotetores/farmacologia , Doenças Neurodegenerativas/metabolismo , Camundongos Endogâmicos C57BL , alfa-Sinucleína/metabolismo , Substância Negra , Neurônios Dopaminérgicos , Chá , Anti-Inflamatórios/farmacologia , Citocinas/metabolismo , Modelos Animais de Doenças
3.
Anal Methods ; 16(12): 1763-1769, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38450684

RESUMO

Development of combined mass spectrometry ionization sources has enabled expansion of the application and scope of mass spectrometry. A novel hybrid ionization system combining vacuum ultraviolet (VUV) and atmospheric pressure chemical ionization (APCI) was constructed. Gaseous samples were self-aspirated into an ionization zone through a capillary by negative pressure, generated by high-speed airflow based on the Venturi effect. Compared with APCI mode alone, the signal-to-noise ratio (S/N) in APCI/VUV mode was increased by about 276-times. To increase the ionization efficiency further, correlated experimental conditions were optimized. Four types of volatile organic compounds (VOCs) were tested to evaluate the performance of the APCI/VUV ion source. Excellent linearity and limit of detection were achieved for compounds in mixed solutions. Quantitative analyses of four VOCs (toluene, cyclohexanone, styrene and ethylbenzene) using APCI/VUV-MS were done, and the relative standard deviations (RSDs) were 1.57%, 6.30%, 4.49% and 8.21%, respectively, indicating that the APCI/VUV ionization source had excellent reproducibility. Our results demonstrated that the developed method was promising for analyzing VOCs as well as being rapid, simple, and easy to operate.

4.
Support Care Cancer ; 32(3): 151, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38332357

RESUMO

PURPOSE: To evaluate the effect of telehealth interventions on adherence to endocrine therapy among patients with breast cancer. METHODS: A systematic search of five English databases (PubMed, Web of Science, Embase, the American Psychological Association PsycNet, and the Cochrane Library) and four Chinese databases (Chinese National Knowledge Infrastructure, SinoMed, WanFang Data, and WeiPu Data) was performed from inception to March 31, 2023. Two investigators independently screened the available studies for eligibility and extracted relevant data. Quality assessment was conducted using the Cochrane Risk of Bias Tool. The effect size was computed based on the risk ratio for dichotomous data and standardized mean difference for continuous data using Review Manager 5.4. RESULTS: A total of 1,780 participants from eight randomized controlled trials were included. These studies involved treatment with aromatase inhibitors only (n = 3) or aromatase inhibitors plus tamoxifen (n = 5). Telehealth interventions involved web-based interventions, telephone-based interventions, interventions via mobile applications, and interventions based on technology. In three studies, subjective measures were used, while objective measures were utilized in another three. Two studies incorporated a combination of both subjective and objective measures. The duration of the interventions varied among studies, ranging from a week to 36 months. The follow-up duration ranged from 4 weeks to 36 months. The quality of included studies was moderate to high. The meta-analysis of the five studies reporting dichotomous data showed that telehealth interventions had a significant effect on adherence to endocrine therapy (RR = 0.86, 95% CI = 0.76-0.97). Moreover, four studies reported continuous data. The meta-analysis demonstrated that telehealth interventions significantly improved adherence to endocrine therapy at 1 month (SMD = 0.50, 95% CI = 0.10-0.90), 3 months (SMD = 0.58, 95% CI = 0.17-0.99), and 6 months (SMD = 0.27, 95% CI = 0.08-0.47) of follow-up. CONCLUSION: Telehealth interventions may facilitate adherence to endocrine therapy among patients with breast cancer. Further research should adopt a theory-based design and explore the longer-term effects.


Assuntos
Neoplasias da Mama , Telemedicina , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Inibidores da Aromatase
5.
Adv Sci (Weinh) ; 11(11): e2308445, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38229156

RESUMO

Biological macromolecules exhibit emergent functions through hierarchical self-assembly, a concept that is extended to design artificial supramolecular assemblies. Here, the first example of breaking the common parallel arrangement of capsule-shaped zirconium coordination cages is reported by constructing the hierarchical porous framework ZrR-1. ZrR-1 adopts a quaternary structure resembling protein and contains 12-connected chloride clusters, representing the highest connectivity for zirconium-based cages reported thus far. Compared to the parallel framework ZrR-2, ZrR-1 demonstrated enhanced stability in acidic aqueous solutions and a tenfold increase in BET surface area (879 m2  g-1 ). ZrR-1 also exhibits excellent proton conductivity, reaching 1.31 × 10-2 S·cm-1 at 353 K and 98% relative humidity, with a low activation energy of 0.143 eV. This finding provides insights into controlling the hierarchical self-assembly of metal-organic cages to discover superstructures with emergent properties.

6.
Adv Healthc Mater ; 13(5): e2302495, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38056018

RESUMO

Emerging research suggests that mitochondrial DNA is a potential target for cancer treatment. However, achieving precise delivery of deoxyribozymes (DNAzymes) and combining photodynamic therapy (PDT) and DNAzyme-based gene silencing together for enhancing mitochondrial gene-photodynamic synergistic therapy remains challenging. Accordingly, herein, intelligent supramolecular nanomicelles are constructed by encapsulating a DNAzyme into a photodynamic O2 economizer for mitochondrial NO gas-enhanced synergistic gene-photodynamic therapy. The designed nanomicelles demonstrate sensitive acid- and red-light sequence-activated behaviors. After entering the cancer cells and targeting the mitochondria, these micelles will disintegrate and release the DNAzyme and Mn (II) porphyrin in the tumor microenvironment. Mn (II) porphyrin acts as a DNAzyme cofactor to activate the DNAzyme for the cleavage reaction. Subsequently, the NO-carrying donor is decomposed under red light irradiation to generate NO that inhibits cellular respiration, facilitating the conversion of more O2 into singlet oxygen (1 O2 ) in the tumor cells, thereby significantly enhancing the efficacy of PDT. In vitro and in vivo experiments reveal that the proposed system can efficiently target mitochondria and exhibits considerable antitumor effects with negligible systemic toxicity. Thus, this study provides a useful conditional platform for the precise delivery of DNAzymes and a novel strategy for activatable NO gas-enhanced mitochondrial gene-photodynamic therapy.


Assuntos
DNA Catalítico , Nanopartículas , Fotoquimioterapia , Porfirinas , Genes Mitocondriais , Oxigênio Singlete , Fármacos Fotossensibilizantes/farmacologia , Linhagem Celular Tumoral
7.
PeerJ ; 11: e16010, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37719116

RESUMO

Background: Previous studies have discussed the effects of grazing and house feeding on yaks during the cold season when forage is in short supply, but there is limited information on the effects of these feeding strategies on Jersey cows introduced to the Tibetan Plateau. The objective of this study was to use genomics and metabolomics analyses to examine changes in rumen microbiology and organism metabolism of Jersey cows with different feeding strategies. Methods: We selected 12 Jersey cows with similar body conditions and kept them for 60 days under grazing (n = 6) and house-feeding (n = 6) conditions. At the end of the experiment, samples of rumen fluid and serum were collected from Jersey cows that had been fed using different feeding strategies. The samples were analyzed for rumen fermentation parameters, rumen bacterial communities, serum antioxidant and immunological indices, and serum metabolomics. The results of the study were examined to find appropriate feeding strategies for Jersey cows during the cold season on the Tibetan plateau. Results: The results of rumen fermentation parameters showed that concentrations of acetic acid, propionic acid, and ammonia nitrogen in the house-feeding group (Group B) were significantly higher than in the grazing group (Group G) (P < 0.05). In terms of the rumen bacterial community 16S rRNA gene, the Chao1 index was significantly higher in Group G than in Group B (P = 0.038), while observed species, Shannon and Simpson indices were not significantly different from the above-mentioned groups (P > 0.05). Beta diversity analysis revealed no significant differences in the composition of the rumen microbiota between the two groups. Analysis of serum antioxidant and immune indices showed no significant differences in total antioxidant capacity between Group G and Group B (P > 0.05), while IL-6, Ig-M , and TNF-α were significantly higher in Group G than in Group B (P < 0.05). LC-MS metabolomics analysis of serum showed that a total of 149 major serum differential metabolites were found in Group G and Group B. The differential metabolites were enriched in the metabolic pathways of biosynthesis of amino acids, protein digestion and absorption, ABC transporters, aminoacyl-tRNA biosynthesis, mineral absorption, and biosynthesis of unsaturated fatty acids. These data suggest that the house-feeding strategy is more beneficial to improve the physiological state of Jersey cows on the Tibetan Plateau during the cold season when forages are in short supply.


Assuntos
Antioxidantes , Rúmen , Animais , Feminino , Bovinos , RNA Ribossômico 16S/genética , Tibet , Metaboloma
8.
Anal Chim Acta ; 1278: 341717, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37709460

RESUMO

Accurate and sensitive measurements of free fatty acids (FFAs) in biological samples are valuable for diagnosing and prognosing diseases. In this study, an in-source microdroplet derivation strategy combined with high-resolution mass spectrometry was developed to analyze FFAs in lipid extracts of biological samples directly. FFAs were rapidly derivated with 2-picolylamine (PA) in the microdroplet which is derived by electrospray. With the proposed method, twelve typical FFAs were determined reliably with high sensitivity and acceptable linearities (R2 ≥ 0.94). The LODs and LOQs for the twelve FFAs were 9-76 pg mL-1 and 30-253 pg mL-1, respectively. The developed method was applied to analyze the alteration of FFAs in liver and kidney samples of rats induced by perfluorooctane sulfonate (PFOS) exposure. The good results demonstrate that the established analysis technique is dependable and has promising applications in detecting FFAs associated with complex biological samples.


Assuntos
Ácidos Graxos não Esterificados , Rim , Animais , Ratos , Limite de Detecção , Fígado , Espectrometria de Massas
9.
Anal Chim Acta ; 1278: 341739, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37709471

RESUMO

Nicotine is an addictive substance often found in tobacco and cigarette smoke and excessive exposure to it can cause various diseases. Herein, core-molecule-shell gold/4-aminothiophenol/silver nanorods (Au@PATP@Ag NRs) were prepared for quantitative detection of nicotine by using surface-enhanced Raman scattering (SERS) technology. The obtained Au@PATP@Ag NRs showed an outstanding SERS effect due to the plasticity of their morphology and the bimetallic synergistic effect between the excellent stability of Au and the highly enhanced effect of Ag. The Au@PATP@Ag NRs substrate exhibited an extremely high enhancement factor (EF) of 2.17 × 107. In addition, in-situ synthesized PATP was used as an internal standard to correct signal fluctuation and improve the reliability of quantitative nicotine detection. A wide linear dynamic range from 10-8 to 10-3 M was obtained and an ultra-low limit of detection (LOD) was about 3.12 × 10-9 M, which was superior to most of previously reported methods. This work has also been used for determining nicotine content in cigarettes and simulated environmental tobacco smoke by using a portable device. These results indicated that the developed SERS method had many potential applications in the quantitative determination of nicotine in real tobacco samples.


Assuntos
Nanotubos , Nicotina , Reprodutibilidade dos Testes , Análise Espectral Raman , Tecnologia
10.
Sci Total Environ ; 903: 166478, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37625726

RESUMO

Cadmium (Cd), a toxic heavy metal, exerts deleterious effects on neuronal survival and cognitive function. NOD-like receptor 3 (NLRP3) inflammasome-dependent pyroptosis has been linked to Cd-induced cytotoxicity. The current research intended to elucidate the role of NLRP3 inflammasome-mediated pyroptosis in Cd-evoked neuronal death and cognitive impairments and the underlying mechanisms. Exposure to 1 mg/kg Cd for 8 weeks led to hippocampal-dependent cognitive deficits and neural/synaptic damage in mice. NLRP3 inflammasome-related protein expression (NLRP3, ASC, and caspase1 p20) and neuronal pyroptosis were significantly upregulated in Cd-treated hippocampi and SH-SY5Y cells. Moreover, pretreatment with the NLRP3 inhibitor MCC950 mitigated Cd-elicited NLRP3 inflammasome activation and subsequent neuronal pyroptosis in SH-SY5Y cells. Furthermore, exposure to Cd downregulated Sirt3 expression, suppressed SOD2 activity by hyperacetylation, and enhanced mtROS accumulation in vivo and in vitro. Notably, Cd-induced NLRP3 inflammasome-dependent neuronal pyroptosis was attenuated by a mtROS scavenger or Sirt3 overexpression in SH-SY5Y cells. In addition, Cd failed to further suppress SOD activity and activate NLRP3 inflammasome-dependent neuronal pyroptosis in Sirt3 shRNA-treated SH-SY5Y cells. Collectively, our findings indicate that Cd exposure induces neuronal injury and cognitive deficits by activating NLRP3 inflammasome-dependent neuronal pyroptosis and that activation of the NLRP3 inflammasome is partially mediated by the Sirt3-mtROS axis.

11.
Materials (Basel) ; 16(14)2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37512428

RESUMO

Reaction-bonded boron carbide (RBBC) composites have broad application prospects due to their low cost and net size sintering. The microstructure, reaction mechanism of boron carbide with molten silicon (Si), and mechanical properties have been substantially studied. However, the mechanical properties strengthening mechanism of reaction-bonded boron carbide composites are still pending question. In this study, dense boron carbide ceramics were fabricated by liquid Si infiltration of B4C-C preforms with dispersed carbon black (CB) as the carbon source. Polyethyleneimine (PEI) with a molecular weight of 1800 was used as the dispersant. CB powders uniformly distributed around boron carbide particles and efficiently protected them from reacting with molten Si. The uniformly distributed CB powders in situ reacted with molten Si and formed uniformly distributed SiC grains, thus forming a continuous boron carbide-SiC ceramic skeleton. Meanwhile, the Si content of the composites was reduced. Using PEI-dispersed CB powders as additional carbon source, the composites' flexural strength, fracture toughness, and Vickers hardness reach up to 470 MPa, 4.6 MPa·m1/2, and 22 GPa, which were increased by 44%, 15%, and 10%, respectively. The mechanisms of mechanical properties strengthening were also discussed.

12.
Nanoscale Adv ; 5(13): 3527-3535, 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37383071

RESUMO

Coordination polymers (CPs) have emerged as promising candidates for photocatalytic H2 production owing to their structural tailorability and functional diversity. However, the development of CPs with high energy transfer efficiency for highly efficient photocatalytic H2 production in a wide pH range still faces many challenges. Here we constructed a novel tube-like Pd(ii) coordination polymer with well-distributed Pd nanoparticles (denoted as Pd/Pd(ii)CPs) based on the coordination assembly of rhodamine 6G and Pd(ii) ions and further photo-reduction under visible light irradiation. Both the Br- ion and double solvent play a key role in forming the hollow superstructures. The resulting tube-like Pd/Pd(ii)CPs exhibit high stability in aqueous solution with the pH range from 3 to 14 due to the high Gibbs free energies of protonation and deprotonation, which provides the feasibility of photocatalytic hydrogen generation in a wide pH range. Electromagnetic field calculations showed that the tube-like Pd/Pd(ii)CPs have a good confinement effect on light. Therefore, the H2 evolution rate could reach 112.3 mmol h-1 g-1 at pH 13 under visible light irradiation, which is far superior to those of reported coordination polymer-based photocatalysts. Moreover, such Pd/Pd(ii)CPs could also reach a H2 production rate of 37.8 mmol h-1 g-1 in seawater under visible light with low optical density (40 mW cm-2) close to morning or cloudy sunlight. The above unique characteristics make the Pd/Pd(ii)CPs possess great potential for practical applications.

13.
Food Res Int ; 171: 113063, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37330856

RESUMO

Molecular mechanisms of caramel-like odorant-olfactory receptor interactions were investigated based on molecular docking and molecular dynamics simulations. The transmembrane regions TM-3, TM-5 and TM-6 of receptors were main contributors of amino acid residues in the docking. Molecular docking results showed that hydrogen bonding and pi-pi stacking were the key forces for the stabilization of caramel-like odorants. The binding energies were positively correlated with the molecular weight of caramel-like odorants. Residues Asn155 (84%, OR2W1), Asn206 (86%, OR8D1), Ser155 (77%, OR8D1), Asp179 (87%, OR5M3), Val182 (84%, OR2J2) and Tyr260 (94%, OR2J2) with high frequencies played an important role in the complexes formation. Odorants 4-hydroxy-5-methylfuran-3(2H)-one (16#) and methylglyoxal (128#) were screened by molecular field-based similarity analysis, which tended to bind to the receptors OR1G1 and OR52H1 respectively, resulting a caramel-like aroma perception. The obtained results are useful for better understanding the perception of caramel-like odorants and their high-throughput screening.


Assuntos
Odorantes , Receptores Odorantes , Odorantes/análise , Receptores Odorantes/química , Receptores Odorantes/metabolismo , Simulação de Acoplamento Molecular , Química Computacional , Olfato
14.
Talanta ; 259: 124539, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37084603

RESUMO

The sensitive and selective nicotine detection in cigarette is necessary due to the cigarette addiction problem and the neurotoxicity of nicotine on human body. In this study, a novel electrochemiluminescence (ECL) emitter with excellent performance was prepared for nicotine analysis, by combining Zr-based metal organic framework (Zr-MOF) and branched polyethylenimine (BPEI)-coated Ru(dcbpy)32+ through electrostatic interaction. Ru(dcbpy)32+ integrated by Zr-MOF could be catalyzed by the reaction intermediates SO4•-, produced from the co-reactant S2O82-, resulting in a significant increase in ECL response. Interestingly, SO4•- with strong oxidizing ability could preferentially oxidize nicotine, leading to ECL quenching. The constructed ECL sensor based on the Ru-BPEI@Zr-MOF/S2O82- system displayed ultrasensitive determination of nicotine with a lower detection limit of 1.9 × 10-12 M (S/N = 3), which is three orders lower than previously reported ECL results and 4-5 orders lower than that of other types of method. This method puts forward a new approach for building efficient ECL system with greatly improved ECL sensitivity for nicotine detection.


Assuntos
Técnicas Biossensoriais , Estruturas Metalorgânicas , Humanos , Nicotina , Medições Luminescentes/métodos , Técnicas Biossensoriais/métodos , Fotometria , Técnicas Eletroquímicas/métodos , Limite de Detecção
15.
Molecules ; 28(8)2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37110608

RESUMO

Surface browning plays a major role in the quality loss of fresh-cut potatoes. Untargeted metabolomics were used to understand the metabolic changes of fresh-cut potato during the browning process. Their metabolites were profiled by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC-HRMS). Data processing and metabolite annotation were completed by Compound Discoverer 3.3 software. Statistical analysis was applied to screen the key metabolites correlating with browning process. Fifteen key metabolites responsible for the browning process were putatively identified. Moreover, after analysis of the metabolic causes of glutamic acid, linolenic acid, glutathione, adenine, 12-OPDA and AMP, we found that the browning process of fresh-cut potatoes was related to the structural dissociation of the membrane, oxidation and reduction reaction and energy shortage. This work provides a reference for further investigation into the mechanism of browning in fresh-cut products.


Assuntos
Solanum tuberosum , Cromatografia Líquida de Alta Pressão , Solanum tuberosum/química , Metabolômica/métodos , Espectrometria de Massas/métodos , Oxirredução
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 294: 122535, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-36857865

RESUMO

Among various chemiluminescence (CL) systems, luminol-H2O2 system is used extensively due to its cheapness and sensitivity. Herein, 4-hydroxy-3-methoxybenzaldehyde, known as vanillin, was firstly found to be able to catalyze H2O2 very efficiently to produce •OH and O2•-, which can be used to enhance the CL of luminol-H2O2 as Co+. In alkaline aqueous solution, vanillin catalyzed the dissociation of H2O2 into active •OH and O2•- radicals and accelerated luminol-H2O2 reaction to emit strong CL signal. Combining the stabilizing function of ß-CD, CL intensity of luminol-H2O2 was enhanced further. Thus, dual-signal amplification of luminol-H2O2 chemiluminescence based on the catalyzing function of vanillin and the stabilizing function of ß-CD was proposed and its mechanism was explored deeply in the manuscript. Interestingly, vanillin is a highly prized flavor compound broadly used as food additive, however, the excessive intake of vanillin is harmful to human and thus the determination of vanillin is very important. On the basis of the luminol-ß-CD-H2O2/vanillin reaction, a low-cost, rapid and simple CL sensor has been established to detect vanillin. The sensor was able to detect vanillin in the range of 1.0 µM âˆ¼ 75 µM with a detection limit of 0.89 µM (S/N = 3). It can also be used for CL imaging detection with satisfactory results.


Assuntos
Luminescência , Luminol , Humanos , Peróxido de Hidrogênio , Medições Luminescentes/métodos , Catálise , Limite de Detecção
17.
Anal Chim Acta ; 1244: 340857, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36737146

RESUMO

ß-amyloid peptide (Aß) aggregates are regarded as a typical neuropathology hallmark for the diagnosis of Alzheimer's disease (AD). Aß40 aggregates include soluble oligomers (Aß40O) and insoluble fibrils (Aß40F). Both of them can simultaneously bind to two different kinds of its aptamer (Apt1 and Apt2). As a mass-sensitive sensing platform, quartz crystal microbalance (QCM) converts changes in mass on the Au chip surface into frequency shift. Here, a dual-aptamer assisted Aß40 aggregates assay was developed. Taking Aß40O detection as an example, Apt2 was modified on the surface of Au chip by Au-S bond. Subsequently, the solution consisted of Aß40O and gold nanoparticles-Apt1 (AuNPs-Apt1) were injected into the QCM chamber. As a result, Aß40O was specifically recognized and captured by Apt2. AuNPs-Apt1 were also combined on the surface of the Au chip because Aß40O can simultaneously bind to Apt1. Then, a significant frequency shift occurred because of the large weight of AuNPs. Similarly, this procedure can be used to detect Aß40F. This QCM biosensor was able to detect Aß40O with a range of 0.2-10 pM with a detection limit of 0.11 pM, while the linear range for Aß40F was 0.1-10 pM with a detection limit of 0.02 pM. This QCM biosensor was simple and highly sensitive, which provided a new method for Aß40 aggregates detection.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Peptídeos beta-Amiloides/química , Ouro/química , Nanopartículas Metálicas/química , Técnicas de Microbalança de Cristal de Quartzo/métodos , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Quartzo
18.
Water Environ Res ; 95(1): e10837, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36683357

RESUMO

Although the addition of excess sludge fermentation products to improve nutrient removal from sewage is cost-effective, its application has rarely been demonstrated. In this study, the external sludge was first collected and fermented under a sludge retention time of 10 days, then introduced into SBR with a 1:15 sewage ratio. The results revealed a gradual increase in the nitrite accumulation ratio to 34.7% in the SBR at the end of the oxic stage after 64 days of adding fermented sludge products. In addition, the average effluent total nitrogen and phosphorous decreased to 7.3 and 0.5 mg/L, corresponding to removal efficiencies of 86.7% and 95.5%, respectively. On the other hand, the use of the fermented sludge products as external organic carbon sources in the SBR increased the external sludge reduction ratio to 42.5%. High-throughput sequencing demonstrated that the increase in the endogenous denitrifier community, polyphosphate-accumulating organisms, and fermentation bacteria were the main factors contributing to the increase in nutrient removal and excess sludge reduction. The economic evaluation indicated that the operational cost of the pilot-scale system saves 0.011$/m3 of sewage treated. PRACTITIONER POINTS: Fermented sludge addition effectively enhanced nutrient removal in pilot-scale SBR. Average effluent TN and PO4 3- -P decreased to 7.3 and 0.5 mg/L, respectively. Highest external sludge reduction rate was 42.5% in pilot-scale reactor. Sewage treatment cost can save 0.011$/m3 under advanced nutrient removal.


Assuntos
Reatores Biológicos , Esgotos , Esgotos/microbiologia , Fermentação , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos/métodos
19.
Sci Total Environ ; 854: 158768, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36108867

RESUMO

Biotreatment of high load hydrogen sulfide (H2S) can lead to rapid acidification of a bioreactor, which greatly challenges the application of bio-desulfurization technology. In this study, the bio-desulfurization performance was improved by enriching acidophilic mixotrophic sulfur-oxidizing bacteria (SOB) by adding organics under extremely acidic conditions (pH < 1.0). A biotrickling filter (BTF) for the removal of H2S was established and operated under pH < 1.0 for 420 days. In the autotrophic period, the maximum H2S elimination capacity (ECmax-H2S) was 135.8 g/m3/h with biofilm mass remaining within 11.1 g/L-BTF. The autotrophic SOB bacterium Acidithiobacillus was dominant (62.1 %). When glucose was added to the BTF system, ECmax-H2S increased by 272 % to 464.3 g/m3/h as biofilm mass increased to 22.3 g/L-BTF. The acidophilic mixotrophic SOB bacteria Mycobacterium (78.4 %) and Alicyclobacillus (20.7 %) were enriched while Acidithiobacillus was gradually eliminated (<0.1 %). Furthermore, the major sulfur metabolism pathways were identified to explore the desulfurization mechanism under extremely acidic conditions. To maintain optimal desulfurization performance and avoid biofilm overgrowth in the BTF system, biofilm mass should be maintained within 20-22 g/L-BTF. This can be achieved by adding 1.0 g/L-BTF glucose every 20 days under a load rate of H2S in 50-90 g/m3/h and a trickling liquid velocity of 1.8 m/h. Extremely acidic conditions eliminated non-aciduric microorganisms so that the addition of organics can increase the abundance of acidophilic mixotrophic SOB (>99 %), thus offering a novel strategy for enhancing H2S removal.


Assuntos
Acidithiobacillus , Sulfeto de Hidrogênio , Filtração , Reatores Biológicos , Bactérias/metabolismo , Enxofre/metabolismo , Acidithiobacillus/metabolismo , Oxirredução , Glucose/metabolismo
20.
Foods ; 11(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36429147

RESUMO

Xiao Mo Xiang You (XMXY) is a traditional Chinese sesame oil variety that is obtained through a hot water flotation process. This unique process gives the oil a unique aroma, health benefits, and excellent product stability. Although XMXY is always the most expensive among all the sesame oil varieties, it is usually used as a flavoring in many traditional Chinese daily food products and is increasingly popular. In order to reveal the characteristics of the oil, the volatile components, sensory evaluation, and oxidation stability of five XMXY samples were, respectively, analyzed by using headspace solid-phase microextraction/gas chromatography−mass spectrometry, an electronic nose, sensory evaluation, and RapidOxy. Comparisons and multidimensional statistical analysis were also carried out to distinguish XMXY from roasted sesame oil (RSO) and cold-pressed sesame oil (CSO) samples. In total, 69 volatiles were identified from XMXY, RSO, and CSO samples. Some compounds possessed high odor activity value (OAV > 1) in XMXY, including heterocyclic compounds, phenols, and sulfur-containing compounds. Additionally, they were also the main volatile components that distinguish XMXY from RSO and CSO. Roasted and nutty aromas were the dominant aroma attributes of XMXY. XMXY had better flavor intensity and oxidation stability than the other two sesame oil samples. These results are very valuable for the quality control and product identification of traditional Chinese sesame oil.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...