Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Sci Total Environ ; : 151761, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34801500

RESUMO

A series of Brønsted acidic ionic liquids (BAILs) functionalized hollow organosilica nanospheres ([C3/4Im][OTs/OTf]-Si(Et)Si, C3/4 = Pr/BuSO3H) were synthesized by two steps. The process involved the preparation of hollow nanosphere supports via a toluene-swollen sol-gel co-condensation of 1,2-bis(trimethoxysilyl)ethane and 3-chloropropyltriethoxysilane in the presence of F127, and followed by a successive quaternary ammonization and protonation with imidazole, 1,3-propane/1,4-butane sultone and trifluoromethane sulfonic acid/p-toluenesulfonic acid. The adjustable acid property, hollow inner diameter (5-15 nm) and shell thickness (5-9 nm) of [C3/4Im][OTs/OTf]-Si(Et)Si are achieved by introducing different organic acids and controlling toluene concentration, respectively. The [C3/4Im][OTs/OTf]-Si(Et)Si were applied in selective conversion of fructose to 5-hydroxymethylfurfural (HMF) and 5-ethoxymethylfurfural (EMF) under microwave heating. Under the optimized conditions, the [C4Im][OTs]-Si(Et)Si3.0 nanospheres with the largest inner diameter and the smallest shell thickness exhibit the highest HMF yield (79.4%, 15 min) in fructose dehydration. And the [C3Im][OTf]-Si(Et)Si0.5 nanospheres with the highest acid strength possess the highest EMF yield (70.4%, 30 min) in fructose ethanolysis. The high Brønsted acid-site density and acid strength of [C3/4Im][OTs/OTf]-Si(Et)Si catalysts accompanied by high microwave heating energy lead to excellent dehydration/ethanolysis activity. The product selectivity strongly depended on the BAILs structures and morphological characteristics of the catalyst. More importantly, the [C3/4Im][OTs/OTf]-Si(Et)Si can be reused three times without changes in leaching of BAILs, due to strong covalent bond between BAILs and silicon/carbon framework. This work will provide a simple strategy of chemically bonded BAILs on suitable supports as efficient solid acids, and an approach of combining morphology-controlled solid acids with microwave-heating for catalytic conversion of biomass/derivatives to fuels and value-added chemicals.

2.
Molecules ; 26(21)2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34771105

RESUMO

To evaluate the important Vitis amurensis germplasm, the quality characteristics and anthocyanin profiles of the ripe berries of 20 V. amurensis grapes and 11 interspecific hybrids in two consecutive years were analysed. Compared with the V. vinifera grapes, V. amurensis grapes had small berries with low total soluble solids and high titratable acids, and were richer in phenolic compounds except for flanan-3-ols in their skins but had lower phenolic contents in their seeds and showed lower antioxidant activities. An outstanding feature of the V. amurensis grapes was their abundant anthocyanin contents, which was 8.18-fold higher than the three wine grapes of V. vinifera. The anthocyanin composition of V. amurensis was characterized by an extremely high proportion of diglucoside anthocyanins (91.71%) and low acylated anthocyanins (0.04%). Interestingly, a new type of speculated 3,5,7-O-triglucoside anthocyanins was first identified and only detected in V. amurensis grapes and hybrids. Based on the total phenolic and anthocyanin characteristics, V. amurensis grapes were set apart from V. vinifera cultivars and the interspecific hybrids, for the same qualities, fell between them, as assessed by principal component analysis.

3.
Oxid Med Cell Longev ; 2021: 9957908, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539976

RESUMO

Background: Pathological changes of the adrenal gland and the possible underlying molecular mechanisms are currently unclear in the case of atherosclerosis (AS) combined with chronic stress (CS). Methods: New Zealand white rabbits were used to construct a CS and AS animal model. Proteomics and bioinformatics were employed to identify hub proteins in the adrenal gland related to CS and AS. Hub proteins were detected using immunohistochemistry, immunofluorescence assays, and Western blotting. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to analyze the expression of genes. In addition, a neural network model was constructed. The quantitative relationships were inferred by cubic spline interpolation. Enzymatic activity of mitochondrial citrate synthase and OGDH was detected by the enzymatic assay kit. Function of citrate synthase and OGDH with knockdown experiments in the adrenal cell lines was performed. Furthermore, target genes-TF-miRNA regulatory network was constructed. Coimmunoprecipitation (IP) assay and molecular docking study were used to detect the interaction between citrate synthase and OGDH. Results: Two most significant hub proteins (citrate synthase and OGDH) that were related to CS and AS were identified in the adrenal gland using numerous bioinformatic methods. The hub proteins were mainly enriched in mitochondrial proton transport ATP synthase complex, ATPase activation, and the AMPK signaling pathway. Compared with the control group, the adrenal glands were larger and more disordered, irregular, and necrotic in the AS+CS group. The expression of citrate synthase and OGDH was higher in the AS+CS group than in the control group, both at the protein and mRNA levels (P < 0.05). There were strong correlations among the cross-sectional areas of adrenal glands, citrate synthase, and OGDH (P < 0.05) via Spearman's rho analysis, receiver operating characteristic curves, a neural network model, and cubic spline interpolation. Enzymatic activity of citrate synthase and OGDH increased under the situation of atherosclerosis and chronic stress. Through the CCK8 assay, the adrenal cell viability was downregulated significantly after the knockdown experiment of citrate synthase and OGDH. Target genes-TF-miRNA regulatory network presented the close interrelations among the predicted microRNA, citrate synthase and OGDH. After Coimmunoprecipitation (IP) assay, the result manifested that the citrate synthase and OGDH were coexpressed in the adrenal gland. The molecular docking study showed that the docking score of optimal complex conformation between citrate synthase and OGDH was -6.15 kcal/mol. Conclusion: AS combined with CS plays a significant role on the hypothalamic-pituitary-adrenal (HPA) axis, promotes adrenomegaly, increases the release of glucocorticoid (GC), and might enhance ATP synthesis and energy metabolism in the body through citrate synthase and OGDH gene targets, providing a potential research direction for future related explorations into this mechanism.

4.
Anal Chem ; 93(39): 13373-13381, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34553925

RESUMO

In this study, a CRISPR/Cas12a (LbCpf1)-mediated electrochemiluminescence (ECL) paper-based platform on the basis of a three-dimensional (3D) DNA walker was proposed for the ultrasensitive detection of miRNA-141. Initially, 3D-rGO with a tremendous loading space was modified on the paper working electrode (PWE) to construct an excellent conductive substrate and facilitate the growth of AuPd nanoparticles (NPs). Afterward, the AuPd NPs were introduced as the coreaction emitter medium of the 3D-rGO/PWE to provide convenience for the transformation between S2O82- and SO42-, amplifying the ECL emission of g-C3N4 nanosheets (NSs). Meanwhile, with the help of Nt.BsmAI nicking endonuclease, a 3D DNA walker signal amplifier was designed to convert and magnify the target miRNA-141 into a particular trigger sequence, which could act as activator DNA to motivate the trans-acting deoxyribonuclease activity of CRISPR/Cas12a to further achieve efficient annihilation of the ECL signal. Furthermore, the proposed multimechanism-driven biosensor exhibited excellent sensitivity and specificity, with a relatively low detection limit at 0.331 fM (S/N = 3) in the concentration range between 1 fM and 10 nM. Consequently, the designed strategy not only extended the application scope of CRISPR/Cas12a but also devoted a new approach for the clinical diagnosis of modern medicine.


Assuntos
Sistemas CRISPR-Cas , MicroRNAs , Sistemas CRISPR-Cas/genética , DNA/genética
5.
Sci Total Environ ; 796: 148946, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34273839

RESUMO

Graphitic carbon nitride (g-C3N4) offers exciting opportunities for sustainable photocatalytic oxidation of organic pollutants but suffers from drawbacks of insufficient oxidation driving force and low quantum efficiency. To over the drawbacks, here a simple and effective strategy was developed to engineer g-C3N4 with simultaneous interstitially embedded potassium dopant and nitrogen defects, and the process included supramolecular preorganization followed by KOH-assisted thermal polycondensation. In the prepared DN-K-CN catalysts, potassium doping level and the amount of nitrogen defects were both controllable. With the increment of potassium doping level, the bandgap of the DN-K-CN became narrow, along with continuously downshifted valence band position. The DN-K-CN showed greatly enhanced visible-light photocatalytic oxidation performance with respect to g-C3N4 in the degradation of emerging phenolic pollutants, acetaminophen and methylparaben; meanwhile, the oxidation performance of DN-K-CN depended on potassium doping level and the amount of nitrogen defects. Combination of experimental findings and theory calculations it is confirmed that the enhanced photocatalytic oxidation performance of DN-K-CN was attributed to the synergistic effect of potassium dopant and nitrogen defects, which resulted in the generation of plentiful active oxygen species and the improvement of oxidation driving force of valence holes. The influence of potassium dopant and nitrogen defects on the electronic and band structures of g-C3N4 was revealed; simultaneously, mechanism of the enhanced photocatalytic oxidation performance of g-C3N4 after the introduction of potassium dopant and nitrogen defects was studied. The present work provided new insights into the electronic and band structure tuning for the improvement of the photocatalytic oxidation performance of g-C3N4.


Assuntos
Nitrogênio , Grafite , Compostos de Nitrogênio , Potássio
6.
ACS Appl Mater Interfaces ; 13(30): 35389-35396, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34291635

RESUMO

Photoelectrochemical (PEC) biosensors carried out the whole reaction process in the same solution, which would limit the sensitivity and selectivity of detection in the sensing system. Herein, we reported a promising new cathode-anode spatial division PEC platform based on the two-electrode synergistic enhancement strategy. With the photoanode and photocathode integrated in the same current circuit, the platform exhibited an increased photocurrent response, as well as an improved anti-interference ability led by separating the two electrodes spatially. In this proposal, red light-driven AgInS2 nanoparticles (NPs) served as the photoanode to build biometric steps and amplify the signal, whereas p-type PbS quantum dots were selected as the photocathode to increase the signal. With the participation of alkaline phosphatase (ALP) labeled on Au NPs-DNA, ascorbic acid 2-phosphate was catalyzed to produce ascorbic acid as an electron donor, resulting in the enhancement of the PEC signal. Interestingly, in the presence of miRNA-21 and T7 Exo, the one-step DNA walker amplification can be triggered to reduce the PEC signal by releasing ALP-Au NP-DNA. The constructed PEC biosensor exhibited a detection limit of as low as 3.4 fM for miRNA-21, which was expected to be applied to early clinical diagnosis. Also, we believe that the proposed cathode-anode spatial division PEC platform can open up a new view for the establishment of other types of PEC biosensors.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Técnicas Eletroquímicas/métodos , Nanopartículas Metálicas/química , MicroRNAs/sangue , Fosfatase Alcalina/química , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Eletrodos , Enzimas Imobilizadas/química , Ouro/química , Humanos , Índio/química , Índio/efeitos da radiação , Chumbo/química , Luz , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Processos Fotoquímicos , Pontos Quânticos/química , Reprodutibilidade dos Testes , Prata/química , Prata/efeitos da radiação , Sulfetos/química
7.
PLoS Comput Biol ; 17(5): e1009029, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34003861

RESUMO

Single-cell RNA sequencing technology provides an opportunity to study gene expression at single-cell resolution. However, prevalent dropout events result in high data sparsity and noise that may obscure downstream analyses in single-cell transcriptomic studies. We propose a new method, G2S3, that imputes dropouts by borrowing information from adjacent genes in a sparse gene graph learned from gene expression profiles across cells. We applied G2S3 and ten existing imputation methods to eight single-cell transcriptomic datasets and compared their performance. Our results demonstrated that G2S3 has superior overall performance in recovering gene expression, identifying cell subtypes, reconstructing cell trajectories, identifying differentially expressed genes, and recovering gene regulatory and correlation relationships. Moreover, G2S3 is computationally efficient for imputation in large-scale single-cell transcriptomic datasets.


Assuntos
Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Biologia Computacional/métodos , Conjuntos de Dados como Assunto , Perfilação da Expressão Gênica , Humanos
8.
Database (Oxford) ; 20212021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34048546

RESUMO

BENviewer is a brand-new online gene interaction network visualization server based on graph embedding models. With mature graph embedding algorithms applied on several interaction network databases, it provides human-friendly 2D visualization based on more than 2000 biological pathways, and these results present not only genes involved but also tightness of interactions in an intuitive way. As a unique visualization server introducing graph embedding application for the first time, it is expected to help researchers gain deeper insights into biological networks beyond generating results explainable by existing knowledge. Additionally, operation flow for users is simplified to greater extent in its current version; meanwhile URL optimization contributes to data acquisition in batch for further analysis. BENviewer is freely available at http://www.bmeonline.cn/BENviewer, besides it is open-sourced at https://github.com/SKLB-lab/BENviewer, http://benviewer.bmeonline.cn.


Assuntos
Redes Reguladoras de Genes , Software , Algoritmos , Bases de Dados Factuais , Epistasia Genética , Humanos
9.
Front Cardiovasc Med ; 8: 639392, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34046437

RESUMO

Background: Elevated serum uric acid (SUA) level is considered an independent predictor of all-cause mortality and the combined endpoint of death or readmission in cardiovascular disease patients. However, the causal relationship between uric acid-lowering therapies (ULTs) and heart failure is still controversial. Design: Meta-analyses were performed to systematically compile available evidence to determine the overall effect of ULTs on heart failure patients. Method: We conducted this systematic review following the PRISMA statement guidelines. Databases were searched to identify randomised controlled trials related to the influence of a ULT intervention in people with heart failure. Data extracted from the included studies were subjected to a meta-analysis to compare the effects of ULTs to a control. Results: Pooled analysis of left ventricular ejection fraction (LEVF) showed an insignificant result towards the ULT group (MD, 1.63%; 95%CI, -1.61 to 4.88; p = 0.32; three studies). Pooled analysis of the 6-Minute Walk Test (6MWT) showed an insignificant result towards the ULT group (MD, 4.59; 95%CI, -12.683 to 22.00; p = 0.61; four studies). Pooled analysis of BNP/NT-pro-BNP led to a nearly statistically significant result towards the ULT group (SMD, -0.30; 95%CI, -0.64 to 0.04; p = 0.08; five studies). Pooled analysis of all-cause mortality and cardiovascular death between ULTs (all XOIs) and placebo did not show a significant difference (RR, 1.26; 95% CI, 0.74 to 2.15, p = 0.39). Conclusion: ULTs did not improve LVEF, BNP/NT-pro-BNP, 6MWT, all-cause mortality, and CV death in heart failure patients. UA may just be a risk marker of heart failure.

10.
World J Clin Cases ; 9(15): 3567-3575, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34046456

RESUMO

BACKGROUND: Peripheral regional block combined with general anesthesia might be a preferable anesthetic regimen for elderly patients undergoing total hip arthroplasty. AIM: To investigate whether ultrasound-guided, direct suprainguinal injection for fascia iliaca block accelerated recovery after general anesthesia and relieved postoperative pain after total hip arthroplasty. METHODS: Patients who underwent total hip arthroplasty under general anesthesia in 2015 or 2019 at The Second Affiliated Hospital of Xuzhou Medical University were retrospectively analyzed. The patients were grouped based on whether preoperative suprainguinal fascia iliaca block was performed or not. The time to tracheal extubation and time spent in the post-anesthesia care unit (PACU), intraoperative remifentanil dosage, fentanyl consumption in the PACU, postoperative cumulative fentanyl consumption within 48 h after operation, visual analogue scale at rest and during movement on the first and second days after surgery, and adverse reactions were compared. RESULTS: Thirty-one elderly patients who underwent total hip arthroplasty were included in the study (block group, n = 16; no-block group, n = 15). The visual analog scale scores at rest and during movement on the first and second days were significantly lower in the block group than in the no-block group (all P < 0.05). Compared with the no-block group, the intraoperative remifentanil dosage was lower, the time to tracheal extubation and the time spent in the PACU were shorter in the block group (all P < 0.01). Fentanyl consumption in the PACU and postoperative cumulative fentanyl consumption in 48 h after operation were lower in the block group (all P < 0.01). The incidence of dizziness was higher in the no-block group than in the block group (P = 0.037). CONCLUSION: Ultrasound-guided, direct suprainguinal injection for fascia iliaca block led to faster recovery after general anesthesia and early postoperative pain relief in elderly patients undergoing total hip arthroplasty.

11.
Immunity ; 54(5): 1083-1095.e7, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33891889

RESUMO

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening post-infectious complication occurring unpredictably weeks after mild or asymptomatic SARS-CoV-2 infection. We profiled MIS-C, adult COVID-19, and healthy pediatric and adult individuals using single-cell RNA sequencing, flow cytometry, antigen receptor repertoire analysis, and unbiased serum proteomics, which collectively identified a signature in MIS-C patients that correlated with disease severity. Despite having no evidence of active infection, MIS-C patients had elevated S100A-family alarmins and decreased antigen presentation signatures, indicative of myeloid dysfunction. MIS-C patients showed elevated expression of cytotoxicity genes in NK and CD8+ T cells and expansion of specific IgG-expressing plasmablasts. Clinically severe MIS-C patients displayed skewed memory T cell TCR repertoires and autoimmunity characterized by endothelium-reactive IgG. The alarmin, cytotoxicity, TCR repertoire, and plasmablast signatures we defined have potential for application in the clinic to better diagnose and potentially predict disease severity early in the course of MIS-C.


Assuntos
COVID-19/imunologia , COVID-19/patologia , SARS-CoV-2/imunologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Síndrome de Resposta Inflamatória Sistêmica/patologia , Adolescente , Alarminas/imunologia , Autoanticorpos/imunologia , Linfócitos T CD8-Positivos/imunologia , Criança , Pré-Escolar , Citotoxicidade Imunológica/genética , Endotélio/imunologia , Endotélio/patologia , Humanos , Células Matadoras Naturais/imunologia , Células Mieloides/imunologia , Plasmócitos/imunologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Índice de Gravidade de Doença
12.
Org Lett ; 23(7): 2710-2714, 2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33749289

RESUMO

The late-stage functionalization of N-unprotected indoles can be useful for modifying low-molecular-weight drugs and bioactive peptides. Whereas indole carboxamides are valuable in pharmaceutical applications, the preparation N-(indol-2-yl)amides with similar structures continues to be challenging. Herein we report on visible-light-induced late-stage photoredox C-H amidation with N-unprotected indoles and tryptophan-containing peptides, leading to the formation of N-(indol-2-yl)amide derivatives. N-Unprotected indoles and aryloxyamides that contain an electron-withdrawing group could be coupled directly to eosin Y as the photocatalyst by irradiation with a green light-emitting diode at room temperature. Mechanistic studies and density functional theory calculations indicate that the transformation might proceed through the oxidative C-H functionalization of indole with a PS* to PS•- cycle. This protocol provides a new toolkit for the late-stage modification labeling and peptide-drug conjugation of N-unprotected indole derivatives.

13.
J Environ Manage ; 287: 112374, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33765522

RESUMO

Municipal sludge is a solid waste material, and resource utilization is the optimal way to dispose of this material. The amount of municipal sludge produced in China is large, and it can be used in the preparation of ceramsite. The content of Al2O3 in drinking water treatment sludge is significantly higher than that in wastewater treatment sludge, while the content of K2O, Na2O and MgO in the two kinds of sludge is similar. When sludge is used to prepare ceramsite, the amount of sludge in most raw materials for ceramsite is less than 50%. The bulk density of the prepared sludge ceramsite is less than 1000 kg m-3, and the highest water absorption rate is close to 40%. The leaching content of heavy metals in municipal sludge-based ceramsite is within the standard health safety limit, and heavy metals are better stabilized. The fitting effect of the pseudo-second-order kinetic equation of the dynamic adsorption of sludge ceramsite is obviously better than that of the pseudo-first-order kinetic equation. Sludge ceramsite used in bio-filter media and constructed wetland (CW) substrates is good able to purify wastewater. In the future, the preparation method of municipal sludge ceramsite and purification research of CW substrates based on sludge ceramsite need to be further improved.


Assuntos
Metais Pesados , Esgotos , China , Misturas Complexas , Água
14.
medRxiv ; 2021 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-33300011

RESUMO

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening post-infectious complication occurring unpredictably weeks after mild or asymptomatic SARS-CoV2 infection in otherwise healthy children. Here, we define immune abnormalities in MIS-C compared to adult COVID-19 and pediatric/adult healthy controls using single-cell RNA sequencing, antigen receptor repertoire analysis, unbiased serum proteomics, and in vitro assays. Despite no evidence of active infection, we uncover elevated S100A-family alarmins in myeloid cells and marked enrichment of serum proteins that map to myeloid cells and pathways including cytokines, complement/coagulation, and fluid shear stress in MIS-C patients. Moreover, NK and CD8 T cell cytotoxicity genes are elevated, and plasmablasts harboring IgG1 and IgG3 are expanded. Consistently, we detect elevated binding of serum IgG from severe MIS-C patients to activated human cardiac microvascular endothelial cells in culture. Thus, we define immunopathology features of MIS-C with implications for predicting and managing this SARS-CoV2-induced critical illness in children.

15.
Anal Chem ; 93(3): 1702-1708, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33369382

RESUMO

This paper introduces a novel potential-resolved paper-based biosensor for simultaneous detection of multiple microRNAs (miRNAs) (taking miRNA-155 and miRNA-126 as examples) based on the bipolar electrode (BPE) electrochemiluminescence (ECL) strategy. The proposed multiple-channel paper-based sensing microfluidic platform was prepared by wax-printing technology, screen-printing method, and in situ Au nanoparticles (AuNPs) growth to form hydrophilic areas, hydrophobic boundaries, waterproof electronic bridge, driving electrode regions, and parallel bipolar electrode regions. CdTe quantum dots (QDs)-H2 and Au@g-C3N4 nanosheets (NSs)-DNA1 were used as dual electrochemiluminescence signal probes, and carboxylated Fe3O4 magnetic nanoparticles existed as carriers. CdTe QDs-H2/S2O82- and Au@g-C3N4 NSs-DNA1/S2O82- could exhibit two strong and stable ECL emissions at a drive voltage of 9 and 12 V, respectively, which can be used as effective potential-resolved signal tags. In addition, the proposed three-dimensional (3D) DNA nanomachine model and the target miRNA cycle strategy were used to achieve double amplification of electrochemiluminescence intensity. More importantly, the combination of the bipolar electrode system and the potential-resolved multitarget electrochemiluminescence method can greatly reduce the spatial interference between substances. The prepared ECL biosensor showed a favorable linear response for the detection of miRNA-155 and miRNA-126 with relatively low detection limits of 5.7 and 4.2 fM, respectively. With excellent sensitivity, the strategy may provide an efficient method for clinical application, especially in detection of trace multiple targets.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Medições Luminescentes , MicroRNAs/análise , Papel , Compostos de Cádmio/química , Eletrodos , Corantes Fluorescentes/química , Ouro/química , Grafite/química , Humanos , Compostos de Nitrogênio/química , Pontos Quânticos/química , Telúrio/química
16.
Mikrochim Acta ; 187(10): 556, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32910220

RESUMO

Based on the etching of gold nanorods (GNRs) and enzyme-linked immunosorbent assay (ELISA), a multicolor immunosensor for visual detection of enterovirus 71 infection is proposed. Once the immunocomplex is formed, the horseradish peroxidase bound to the ELISA plate oxidizes 3,3',5,5'-tetramethylbenzidine (TMB) into TMB2+ in the presence of hydrogen peroxide. Subsequently, TMB2+ quantitatively etches GNRs to the short GNRs, leading to a blue shift of longitudinal localized surface plasmon resonance and corresponding color responses. This change is used to develop two types of cut-off standards, which respond to the human anti-enterovirus at a concentration of 71 IgM antibody. The method has been validated with clinical serum samples and showed high sensitivity and specificity . This visual immunosensor has an important application value for point-of-care detection of EV71, especially in areas lacking detection equipment. Graphical abstract.


Assuntos
Técnicas Biossensoriais/métodos , Enterovirus Humano A/patogenicidade , Ouro/química , Humanos
17.
Bioengineered ; 11(1): 559-571, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32434432

RESUMO

Farmland transfer is one of the essential approaches for achieving large-scale farming and its management affects productive efficiency, environment pollution and food sustainable security supply. Present study was carried out investigation based representative agricultural development area Guanzhong Plain of Shaanxi, aimed at explore the role of biotechnology and laborers in integration of farmland toward to improve sustainable agriculture in rural China by employed the profit and Tobit models evaluation. The conclusion demonstrated that labor's and agricultural management model as main stay, intensive farming has positive effect-based economic and environmental benefits than fragmentation management, female laborers have weaker effect on farmland renting-out behavior among smallholders while male laborers were superior promoters in increasing the area of rented-in farmland and farm scale. Finally, bioengineering development and agricultural intensification management as a rational choice that has great potential value for large-scale cultivation that contributing a promising future for achieving cleaner production, environment and human health further providing huge economic and social and environmental benefits in sustainability agriculture. Additionally, government policies require intensive intervention to accelerate large-scale management and biotechnology implementation.Abbreviation: Aaflf: Average age of female labor force; Incom(log): Log of annual household income; Noflf: Number of women in the labor force; Nooaf: Number of old adults in family; NTFs: non-transfer families; OLS: ordinary least square; Palff: Proportion of agricultural laborers in the female labor force; Palmf: Proportion of agricultural laborers in the male labor force; RIFs: rented-in families; ROFs: rented-out families; Whhf: Whether the household head is female.


Assuntos
Agricultura/métodos , Bioengenharia/métodos , Fazendas , Biotecnologia/métodos , China
18.
Anal Chem ; 92(11): 7604-7611, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32364705

RESUMO

Herein an ultrasensitive photoelectrochemical (PEC)/visual biosensor coupled with a multiple signal amplification strategy was proposed for the detection of nucleic acids. The initial signal amplification was achieved via ternary AgInSe2 quantum dot (QD)-sensitized ZnO nanoflowers (ZnO NFs) to form an excellent photoelectric layer. A gold-modified nanorod-anchored CeO2 (Au@NR-CeO2) octahedron was introduced as a multifunctional signal regulator via the formation of triple helix molecules. The Au@NR-CeO2 octahedron could not only quench the photocurrent signal due to the competitive capture of photon energy and electron donors with the photoelectric layer but could also act like a peroxidase to catalyze the formation of mimetic enzymatic catalytic precipitation (MECP) on the surface of the photoelectric layer. Furthermore, the steric hindrance effect from the Au@NR-CeO2 octahedron further reduced the output of the photocurrent signal. After incubation with t-DNA, the triple helix conformation was disassembled and the Au@NR-CeO2 octahedron was released from the electrode surface, leading to the significant increase of photocurrent signal. Meanwhile, the released Au@NR-CeO2 octahedron could flow into the colorimetric area of the lab-on-paper device to catalyze the occurrence of the color reaction, achieving a visual detection for t-DNA. On the basis of the multiple signal amplification strategy, t-DNA was detected specifically with a lower limit of detection of 0.28 fM and a wider linear range from 0.5 fM to 50 nM. The proposed method has the potential utility to detect a variety of nucleic acids and biomarkers.


Assuntos
Técnicas Biossensoriais , Cério/química , DNA Bacteriano/análise , Técnicas Eletroquímicas , Pontos Quânticos/química , Óxido de Zinco/química , Ouro/química , Índio/química , Nanotubos/química , Processos Fotoquímicos , Selênio/química , Prata/química
19.
J Adhes Dent ; 21(5): 413-421, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31624806

RESUMO

PURPOSE: To evaluate the potential of an additional application of two novel hydrophobic experimental adhesive resins with or without bioactive zinc fluoride glass to promote the bond strength of a one-step self-etch universal adhesive. MATERIALS AND METHODS: Three self-etch universal adhesives, G-Premio Bond (GPB), Scotchbond Universal (SBU) and Clearfil SE Bond 2 (SE2), and two experimental adhesive resins, BZF210 and BZF21, were used in this study; thus, five groups were formed: GPB, GPB+BZF210, GPB+BZF21, SBU, and SE2. The adhesives were applied to flat dentin surfaces according to each manufacturer's instructions. The microtensile bond strengths (µTBS) were evaluated after 24-h water storage. The fracture modes and interfacial structures were analyzed using SEM, while elemental analysis was performed using SEM-EDS. The data were analyzed using one-way ANOVA and the Games-Howell test (p < 0.05). RESULTS: Significantly higher µTBS was achieved by additional application of BZF210 (48.68 ± 6.59 MPa) and BZF21 (58.58 ± 2.84 MPa) compared with GPB (33.57 ± 4.22 MPa) alone. Most failures occurred above the smear layer in GBP, while more cohesive and mixed failures were observed in GBP+BZF210, GPB+BZF21, SBU, and SE2. The interfacial structures revealed that GBP+BZF210 and GPB+BZF21 had more and longer resin tags than did GPB. SEM-EDS showed a particularly high peak of zinc in GPB+BZF21. CONCLUSIONS: The bond strength of GPB was significantly improved by the additional application of BZF210 and BZF21. Using an additional bioactive hydrophobic layer on a one-step, self-etch universal adhesive can significantly improve its bonding efficacy and extend its clinical options.


Assuntos
Colagem Dentária , Resinas Compostas , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência à Tração
20.
J Acoust Soc Am ; 145(4): 2453, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31046378

RESUMO

The purpose of this work is to find a method to locate the scattering centers in spatial domain; by using this information, the mean scatter spacing (MSS) can be estimated, and the spatial information is the one-dimensional imaging of scattering centers. This paper presents a method that can locate the scattering centers in spatial domain robustly and automatically. By incorporating it with fast Fourier transformation, the MSS can be estimated. The three foremost processes, matched filtering, envelope extraction, and peak reconstruction, are incorporated in the authors' algorithm. Monte Carlo simulations demonstrate that the proposed method is a robust one to locate scattering centers in spatial domain, and has a better performance than spectrum-based MSS estimation techniques. Especially exploited in estimating MSS which varies from 0.6 to 1.2 mm in the range of human mean trabecular bone spacing, the proposed method shows great potential in medical use. Simple but widely used phantom experiments demonstrate that the proposed algorithm has the capacity to locate scattering centers in spatial domain.


Assuntos
Modelos Teóricos , Localização de Som , Ondas Ultrassônicas , Condução Óssea , Osso Esponjoso/fisiologia , Análise de Fourier , Humanos , Razão Sinal-Ruído
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...