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1.
Anal Chem ; 96(4): 1693-1699, 2024 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-38231554

RESUMO

Major depressive disorder (MDD) is a prevalent brain disorder affecting more than 2% of the world's population. Due to the lack of well-specific biomarkers, it is difficult to distinguish MDD from other diseases with similar clinical symptoms (such as Alzheimer's disease and cerebral thrombosis). In this work, we provided a strategy to address this issue by constructing a combinatorial biomarker of serum glial fibrillary acidic protein (GFAP) and neurofilament light chain (NFL). To achieve the convenient and sensitive detection of two proteins, we developed an electrochemical immunosandwich sensor using two metal-ion-doped carbon dots (Pb-CDs and Cu-CDs) as probes for signal output. Each probe contains approximately 300 Pb2+ or 200 Cu2+, providing excellent signal amplification. This method achieved detection limits of 0.3 pg mL-1 for GFAP and 0.2 pg mL-1 for NFL, lower than most of the reported detection limits. Analysis of real serum samples showed that the concentration ratio of GFAP to NFL, which is associated with the relative degree of brain inflammation and neurodegeneration, is suitable for not only distinguishing MDD from healthy individuals but also specifically distinguishing MDD from Alzheimer's disease and cerebral thrombosis. The good specificity gives the combinatorial GFAP/NFL biomarker broad application prospects in the screening, diagnosis, and treatment of MDD.


Assuntos
Doença de Alzheimer , Transtorno Depressivo Maior , Trombose Intracraniana , Humanos , Transtorno Depressivo Maior/diagnóstico , Doença de Alzheimer/diagnóstico , Proteína Glial Fibrilar Ácida , Filamentos Intermediários , Chumbo , Biomarcadores
2.
Anal Chem ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940533

RESUMO

Low-mass soluble ß-amyloid peptide oligomers (LSAßOs) play a crucial role in the pathogenesis of Alzheimer's disease. However, these oligomers exhibit heterogeneity in terms of structure, stability, and stoichiometry, and their abundance in biofluids is low, making accurate identification challenging. In this study, we developed a DNA nanocage-assisted method for selective sizing and sensitive quantification of LSAßOs in serum. Using LSAßO less than 10 kDa (LSAßO10kD) and less than 30 kDa (LSAßO30kD) as models, the size-matching rules between DNA nanocages and LSAßOs were investigated, and two appropriate nanocages were selected for the detection of two LSAßOs, respectively. Both nanocages were functionalized by encapsulating oligomer's aptamer and a complementary sequence within their cavities. Once the LSAßO entered the corresponding nanocage cavity, the complementary sequence was released, triggering a hybridization chain reaction on an electrochemical sensing platform. The system achieved size-selective discrimination of LSAßO10kD with a linear range of 10-150 pM and LSAßO30kD with a linear range of 15-150 pM. Real sample testing confirmed the applicability of the method for blood-based diagnosis. The DNA nanocage-assisted electrochemical analysis platform provides an accurate, highly selective, and sensitive approach for oligomer analysis, which is significant for amyloid protein research and related disease diagnosis.

3.
Anal Chem ; 96(16): 6180-6185, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38593062

RESUMO

Chemical recycling is a promising approach to reduce plastic pollution. Timely and accurate size analysis of produced nanoplastics is necessary to monitor the process and assess the quality of chemical recycling. In this work, a sandwich-type microelectrode sensor was developed for the size assessment of nanoplastics. ß-Mercaptoethylamine was modified on the microelectrode to enhance its surface positive charge density. Polystyrene (PS) nanoplastics were captured on the sensor through electrostatic interactions. Ferrocene was used as an electrochemical beacon and attached to PS via hydrophobic interactions. The results show a nonlinear dependence of the sensor's current response on the PS particle size. The size resolving ability of the microelectrode is mainly attributed to the small size of the electrode and the resulting attenuation of the electric field strength. For mixed samples with different particle sizes, this method can provide accurate average particle sizes. Through an effective pretreatment process, the method can be applied to PS nanoplastics with different surface properties, ensuring its application in evaluating different chemical recycling methods.

4.
Anal Chem ; 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36628978

RESUMO

The abundance of brain-derived neurotrophic factor (BDNF) in aqueous humor (AH) is an ideal biomarker for the diagnosis of glaucoma, a chronic progressive optic neuropathy and the most frequent cause of irreversible blindness. The difficulty of AH-based BDNF detection is from the small amount of extracted AH in a paracentesis (<100 µL) and the ultra-low abundance of BDNF. In this work, we systematically studied the non-specific adsorption of biofluids on the bare gold electrode by electrochemistry and Raman spectroscopy techniques, revealing the unexpected negative correlation of the extent of non-specific adsorption with the size of the electrode. Based on it, a simple microelectrode-based sensor without the introduction of the blocking layer was developed for the detection of BDNF in the AH sample. Using electrochemical impedance spectroscopy (EIS) and extracting the changes of electron-transfer resistance of the electrochemical probe [Fe(CN)6]3-/4- on the sensor surface, the BDNF was quantified. The dynamic range was from 0.5 to 50 pg·mL-1, with a detection limit of 0.3 pg·mL-1 and a sample consumption of 5 µL. The real AH sample analysis confirmed the significant decrease of BDNF abundance in the AH of glaucoma patients. Our microelectrode-based EIS sensor displayed prominent advantages on simplified preparation, sensitive response, and low sample consumption. This AH-based BDNF analysis is expected to be used for the screening and diagnosis of glaucoma, especially for the high-risk population who have ocular diseases and have to undergo surgeries.

5.
J Cell Mol Med ; 26(10): 2935-2946, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35388602

RESUMO

The aim of this study was to identify potential biomarkers of TB in blood and determine their function in Mtb-infected macrophages. First of all, WGCNA was used to analyse 9451 genes with significant changes in TB patients' whole blood. The 220 interferon-γ-related genes were identified, and then 30 key genes were screened using Cytoscape. Then, the AUC values of key genes were calculated to further narrow the gene range. Finally, we identified 9 genes from GSE19444. ROC analysis showed that SAMD9L, among 9 genes, had a high diagnostic value (AUC = 0.925) and a differential diagnostic value (AUC>0.865). To further narrow down the range of DEGs, the top 10 hub-connecting genes were screened from monocytes (GSE19443). Finally, we obtained 4 genes (SAMD9L, GBP1, GBP5 and STAT1) by intersections of genes from monocytes and whole blood. Among them, it was found that the function of SAMD9L was unknown after data review, so this paper studied this gene. Our results showed that SAMD9L is up-regulated and suppresses cell necrosis, and might be regulated by TLR2 and HIF-1α during Mtb infection. In addition, miR-181b-5p is significantly up-regulated in the peripheral blood plasma of tuberculosis patients, which has a high diagnostic value (AUC = 0.969).


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia , MicroRNAs , Receptor 2 Toll-Like , Tuberculose , Proteínas Supressoras de Tumor , Biomarcadores , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , MicroRNAs/genética , Mycobacterium tuberculosis , Receptor 2 Toll-Like/genética , Tuberculose/diagnóstico , Tuberculose/genética , Proteínas Supressoras de Tumor/genética
6.
Anal Chem ; 94(37): 12657-12663, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36070514

RESUMO

Most food packages are made of plastics, nanoplastics released from which can be directly ingested and induce serious damage to organisms. Therefore, it is urgent to develop an effective and convenient method for nanoplastic determinations in food packages. In this work, we present a sandwich-based electrochemical strategy for nanoplastic determination. Positively charged Au nanoparticles were coated onto a Au electrode to selectively capture negatively charged nanoplastics in an aqueous environment. Subsequently, the nanoplastics were recognized by the signal molecule ferrocene via the hydrophobic interaction and determined by differential pulse voltammetry. Our sandwich-type detection depends on both electronegativity and hydrophobicity of nanoplastics, which make the method applicable for the assays of packages made of widely commercialized polystyrene (PS), polypropylene (PP), polyethylene (PE), and polyamide (PA). The method displays different sensitivities to above four nanoplastics but the same dynamic range from 1 to 100 µg·L-1. Based on it, the nanoplastics released from several typical food packages were assayed. Teabags were revealed with significant nanoplastic release, while instant noodle boxes, paper cups, and take-out boxes release slightly. The good recoveries in nanoplastic-spiked samples confirm the accuracy and applicability of this method. This work provides a sensitive, low-cost, and simple method without complicated instruments and pretreatment, which is of great significance for the determination of nanoplastics released from food packages.


Assuntos
Nanopartículas Metálicas , Poluentes Químicos da Água , Ouro , Interações Hidrofóbicas e Hidrofílicas , Metalocenos , Microplásticos , Nylons , Plásticos , Polietileno , Polipropilenos , Poliestirenos/química , Eletricidade Estática , Poluentes Químicos da Água/química
7.
Anal Chem ; 94(32): 11433-11440, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35913270

RESUMO

Serum neurofilament light chain (NFL), a potential general biomarker for neurodegenerative diseases, is not specific enough to differentiate neurodegenerative diseases from other brain diseases such as cerebral thrombosis (CT). According to the importance of glycosylation in neurodegenerative pathogenesis, the NFL glycosylation level (oNFL/tNFL), defined as the ratio of glycosylated NFL (oNFL) to total NFL (tNFL), may be a more effective index. The major challenge in serum oNFL/tNFL detection is the ultra-low abundance of both NFL forms. In this paper, we achieved a convenient one-step electrochemical quantitation of oNFL/tNFL based on an interface-solution dual-path amplification strategy. Two amplified electrochemical signals─the reduction of Cu2+ from adsorbed porous nanoparticles on the sensor interface and the reduction of O2 from horseradish peroxidase-catalyzed H2O2 disproportionation in solution─were adopted to quantify tNFL and oNFL, respectively. The electrochemical sensor displayed good sensitivity, selectivity, and reproducibility. The dynamic range is 1-25 pg mL-1 for tNFL and 0.25-25 pg mL-1 for oNFL, respectively. By analyzing the clinic serum samples, for the first time, our work provided the abundance of oNFL in human serum and revealed that the oNFL/tNFL is effective not only in differentiating three kinds of brain damage patients from healthy people but also in differentiating neurodegeneration from non-neurodegeneration CT patients. As a general biomarker, the oNFL/tNFL is more specific than NFL, which is hoped to be a new and valid indicator for the diagnosis, progression, prediction, and treatment evaluation of neurodegenerative diseases.


Assuntos
Filamentos Intermediários , Doenças Neurodegenerativas , Biomarcadores , Glicosilação , Humanos , Peróxido de Hidrogênio , Doenças Neurodegenerativas/diagnóstico , Reprodutibilidade dos Testes
8.
Chem Biodivers ; 19(5): e202200139, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35289981

RESUMO

Globe amaranth flower, the edible inflorescence of Gomphrena globose L., was used to treat dysentery and ulcer as well as other infectious diseases caused by microbes in Southwest China, but its function and bioactive components need experimental support. In this study, phytochemical constituents and antibacterial bioactivity of globe amaranth flower against P. aeruginosa were carried out. As a result, two new (1 and 2) and eleven known (3-11) compounds were isolated, in which compounds 4-7 displayed anti P. aeruginosa bioactivity with the minimum inhibitory concentration (MIC) from 0.008 to 0.256 mg/mL. Furthermore, with aid of the scanning electron microscope (SEM) and a superficial skin infection model in mice, the most potent compound 4 can significantly destroy the structure of bacteria in vitro and restore bacterial infection damage in vivo.


Assuntos
Amaranthaceae , Pseudomonas aeruginosa , Amaranthaceae/química , Animais , Antibacterianos/química , Flores , Camundongos , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia
9.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 47(9): 1253-1259, 2022 Sep 28.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-36411709

RESUMO

OBJECTIVES: Pelvic floor tendons, fascia, and ligaments are rich in proprioceptors. Proprioceptive training can stimulate local proprioceptors to increase neuromuscular responses and promote the recovery of muscle and fascial ligament functions. This study aims to observe the therapeutic effect of proprioception training combined with pelvic floor electrical stimulation biofeedback on postpartum pelvic floor dysfunction (PFD), and to provide evidence for the treatment of postpartum PFD. METHODS: A total of 108 puerpera with postpartum PFD were selected and divided into a control group ( n =50) and an experimental group ( n =58). Puerpera in the control group received pelvic floor electrical stimulation biofeedback treatment. Puerpera in the experimental group received proprioception training combined with pelvic floor electrical stimulation biofeedback treatment. After one course of treatment, the pelvic floor muscle strength, muscle endurance, repetitive contraction ability, rapid contraction ability, percentage of normal vaginal posterior wall elevation, percentage of normal lower abdominal muscle synergistic contraction, percentage of normal reflex contraction during coughing, incidence of stress urinary incontinence (SUI), and staging of pelvic organ prolapse (POP) were compared before and after treatment between the 2 groups. RESULTS: After treatment, all indexes of the 2 groups were better than those before treatment; the pelvic floor muscle strength, muscular endurance, repetitive contraction ability, and rapid contraction ability of the experimental group were better than those of the control group (all P <0.05); the percentage of normal lower abdominal muscle synergistic contraction and percentage of normal reflex contraction during coughing of the experimental group were higher than those of the control group (both P <0.05); the incidence of SUI in the experimental group was lower than that in the control group ( P <0.05); the percentage of POP staging II in the experimental group was significantly lower than that in the control group ( P <0.05). There was no significant difference in the percentage of normal posterior vaginal wall elevation after treatment between the 2 groups ( P >0.05). CONCLUSIONS: Proprioception training combined with pelvic floor electrical stimulation biofeedback could improve the rehabilitation effect of postpartum pelvic floor dysfunction and promote the recovery of pelvic floor function, which possesses important clinical application value.


Assuntos
Diafragma da Pelve , Incontinência Urinária por Estresse , Feminino , Humanos , Terapia por Exercício , Biorretroalimentação Psicológica , Período Pós-Parto/fisiologia , Estimulação Elétrica , Propriocepção
10.
Anal Chem ; 93(8): 3951-3958, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33596054

RESUMO

The aim of this study was to identify the target of nonalcoholic fatty liver disease (NAFLD) cell-specific aptamer NAFLD01 and investigate its effect on lipid metabolism in vitro. A distinct membrane protein of NAFLD cells pulled down by NAFLD01 was analyzed by mass spectrometry to determine target candidates, and affinity of NAFLD01 to target-protein-silent NAFLD cells was detected to validate it. Knockdown of CD36 abolished the binding of NAFLD01, and its binding affinity was associated with membrane-bound CD36. NAFLD01 affinity for NAFLD cells was proportional to the CD36 expression level. Moreover, compared to random sequences, NAFLD01 showed better recognition for both mouse and human tissue sections of NAFLD. Importantly, NAFLD01 could ameliorate liver fat deposition through interaction with CD36 in vitro. Therefore, aptamer NAFLD01 could act as an effective and safe targeted drug for NAFLD. NAFLD01 is the first reported CD36-specific aptamer. This aptamer can improve hepatocyte steatosis via specifically binding to CD36. This study provides a molecular tool to investigate the mechanism of CD36 in NAFLD.


Assuntos
Aptâmeros de Nucleotídeos , Hepatopatia Gordurosa não Alcoólica , Animais , Aptâmeros de Nucleotídeos/metabolismo , Antígenos CD36/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo
11.
Anal Chem ; 93(7): 3611-3617, 2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33571410

RESUMO

Alzheimer's disease (AD) is the most common neurodegenerative disease among the elderly. Abnormal aggregates of both ß-amyloid peptide (Aß) subtypes, Aß42 and Aß40, are the typical neuropathology hallmarks of AD. However, because of the lack of specific recognition elements such as an antibody and aptamer, it is difficult to differentiate and determine the oligomers of Aß42 and Aß40 in clinic. In this paper, we developed a planar bilayer lipid membrane (BLM)-based electrochemical biosensor. According to the dynamic differences on oligomer-induced BLM damage, both low-mass, soluble oligomers of Aß42 and Aß40 (L-Aß42O and L-Aß40O) were measured in turn by electrochemical impedance spectroscopy. The BLM was supported by a porous 11-mercaptoundecanoic acid layer on a gold electrode, which amplified the impedance signal corresponding to the membrane damage and improved the detection sensitivity. The weakly charged surface of the BLM ensured the low non-specific adsorption of coexisting proteins in cerebrospinal fluid (CSF). Using the electrochemical biosensor, L-Aß42O was determined within 20 min, with a linear range from 5 to 500 pM and a detection limit of 3 pM. Meanwhile, L-Aß40O was determined within 60 min, with a linear range from 60 pM to 6.0 nM and a detection limit of 26 pM. The recoveries in oligomer-spiked artificial CSF and human CSF samples confirmed the accuracy and applicability of this proposed method in clinic. This work provides an antibody-free, highly selective, and sensitive method for simultaneous detections of L-Aß42O and L-Aß40O in real CSF samples, which is significant for the early diagnosis and prognosis of AD.


Assuntos
Doença de Alzheimer , Técnicas Biossensoriais , Doenças Neurodegenerativas , Idoso , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides , Humanos , Lipídeos , Fragmentos de Peptídeos
12.
Horm Metab Res ; 53(8): 504-511, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34384107

RESUMO

Insulin resistance (IR) is one of the most common features of polycystic ovary syndrome (PCOS), which is related to obesity. Whether increased anti-Müllerian hormone (AMH) levels in PCOS are involved in the pathogenesis of insulin resistance remains unclear. We investigated serum levels of leptin and AMH along with basic clinical and metabolic parameters in 114 PCOS patients and 181 non-PCOS women. PCOS patients presented higher fasting blood glucose, insulin concentrations and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) in addition to body mass index (BMI), lipids profiles and hormone levels. HOMA-IR showed a positive correlation with BMI, AMH, leptin, and low-density lipoprotein-cholesterol (LDL-c) levels. Interestingly, AMH is strongly positively correlated with HOMA-IR and insulin concentrations for 1st and 2nd hours of glucose treatment after fasting. Among PCOS women with BMI≥25 kg/m2, high AMH level group showed an increased HOMA-IR when compared to normal AMH level. However, among PCOS women with normal BMI, women with high AMH presented an elevated fasting insulin levels but not HOMA-IR when compared to normal AMH group. In vitro treatment of isolated islet cells with high concentration of leptin (200 ng/ml) or high leptin plus high concentration of AMH (1 ng/ml) significantly enhanced insulin secretion. Importantly, co-treatment of AMH plus leptin upregulates the expression of pro-apoptotic proteins, such as Bax, caspase-3, and caspase-8 after incubating with a high level of glucose. These results suggest that AMH may involve in the pathological process of pancreatic ß-cells in obese PCOS women.


Assuntos
Hormônio Antimülleriano/fisiologia , Resistência à Insulina , Síndrome do Ovário Policístico/metabolismo , Adulto , Animais , Hormônio Antimülleriano/sangue , Hormônio Antimülleriano/farmacologia , Feminino , Humanos , Hiperinsulinismo/etiologia , Secreção de Insulina/efeitos dos fármacos , Leptina/farmacologia , Ratos , Adulto Jovem
13.
Nanotechnology ; 32(7): 075602, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33241790

RESUMO

The mercury ions in waste water have threatened public health and environmental protection. In this sense, novel materials with outstanding performances for removal of Hg2+ are imperative. Herein, we demonstrate a thiol-functionalized zirconium metal-organic cage (MOC-(SH)2) with excellent dispersion displays ideal properties for Hg2+ capture. MOC-(SH)2 exhibits the ability of removing Hg2+ in aqueous solutions with a capacity of 335.9 mgHg2+/gMOC-(SH)2, which surpasses that of classical Zr-based metal-organic framework Uio-66-(SH)2 by 1.89 folds. The higher loading capacity of MOC-(SH)2 is probably owing to the excellent dispersion of the discrete cage, which makes the accessibility of binding sites (thiol) easier. Additionally, 99.6% of Hg2+ can be effectively captured by MOC-(SH)2 with the concentration decreased from 5 to 0.02 ppm reaching the permissible limit for Hg2+, outperforming the performance of Uio-66-(SH)2. The excellent absorption property of MOC-(SH)2 is also achieved in terms of superior selectivity under the presence of competitive metal ions. Meanwhile, the regenerated MOC-(SH)2 can be reused without apparent loss of Hg2+ loading capacity. UV-vis absorption spectra, IR spectra and emission spectra further verified the strong chemical affinity between Hg2+ and the thiol of MOC-(SH)2. The study lays the groundwork for using Zr-MOCs in the removal of toxic metal ions and environmental sustainability.

14.
Chem Eng Sci ; 242: 116749, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36530354

RESUMO

During the outbreak of COVID-19, the fogging of goggles was a fatal problem for doctors. At present, there are many ways to prevent fogging by adjusting surface wettability. However, the mechanical properties of most super-hydrophilic antifogging coatings are poor, easy to lose their antifogging properties when encountering fingers or cloth friction. To address this issue, the Konjac Glucomannan was cross-linked with water-soluble silicone fluid to form a binder, then being combined with the modified Ecokimera to prepare an eco-friendly super-hydrophilic coating that possessed excellent super-hydrophilicity, and the water contact angle (WCA) was 2.51 ± 1°. In addition, the WCA is still about 5° after 180 times of antifogging tests. The friction resistance of the coating was as high as 24 m. Moreover, the light transmittance was only reduced by 3%. Besides, they also had the excellent self-cleaning property. After being stored in the laboratory environment for 90 days, it can still maintain the hydrophilic property (WCA is about 5°). In general, the method proposed in this study is low-cost and eco-friendly, and can be widely used in the preparation of antifogging coatings.

15.
Anal Chem ; 92(5): 4115-4122, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32003219

RESUMO

Noble metal nanoparticles (NPs) have enabled surface-enhanced Raman scattering (SERS) for in situ monitoring of NPs-catalyzed reactions. However, it still remains a great challenge to ensure that analytes without plasmonic metal surface-affinity groups (such as thiol and amino groups) can be located into hotspots and detected by SERS. Here, we report a novel sacrificial template method for the fabrication of "pomegranate-like" plasmonic nanoreactors (PPNs), in which high-density embedded AuNPs simultaneously generated SERS enhancement and catalytic performance. Once the analytes entering PPNs are catalyzed and meanwhile located into the hotspots, in situ SERS monitoring of catalytic reactions can be achieved. The intense hotspots of localized electric fields of PPNs were evaluated by finite-difference time-domain simulation. By using PPNs as a substrate, SERS signals of molecules without Au surface-affinity groups were obtained, such as p-naphthoquinone and 4-nitrophenol. The PPNs showed high catalytic activities in the reduction of 4-nitrothiophenol to 4-aminothiophenol and 4-nitrophenol to 4-aminophenol, respectively. Besides, the SERS spectra of both 4-nitrophenol and 4-aminophenol during the reduction reaction of 4-nitrophenol with NaBH4 were first obtained, demonstrating their utilization in the detection of catalytic reactions.

16.
Org Biomol Chem ; 18(8): 1637-1646, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32037417

RESUMO

A catalytic asymmetric synthesis of 3,4-dihydrocoumarins with adjacent tertiary-quaternary stereocenters by 1,6-addition/transesterification cascade reaction of α-isocyanoacetates with ortho-hydroxyphenyl-substituted para-quinone methides (p-QMs) has been developed. Using a combination of dihydroquinidine-derived aminophosphine and silver nitrate as a binary catalytic system, moderate to good yields, excellent diastereoselectivities (>20 : 1 dr) and good to excellent enantioselectivities (up to 94% ee) were achieved for a wide range of isocyanoacetates and p-QMs.

17.
Nanotechnology ; 31(40): 405603, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32526722

RESUMO

The plasmonic properties of individual metallic nanostructures are of great importance for application in surface science, materials science, and nanophotonics. Herein, being facilitated with a home-made flow device and pulsed laser irradiation, we proposed a batch preparation protocol towards spherical Au nanoparticles (Au NPs) and cage shell entrapped spherical core nanoparticles (Au@cAu NPs) with highly uniform morphology and a tunable size distribution. The Fano resonance behavior exhibited by the effective interaction between spherical Au NPs and the silicon surface has great potential for the design of ultrasensitive optical sensing devices. In comparison with the spherical Au NP, the individual Au@cAu NP displayed not only a red-shifted and broadened localized surface plasmon resonance (LSPR) scattering peak, but also a higher electromagnetic field enhancement. Therefore, the Au@cAu NPs offer a better choice for plasmonic enhancement-based applications in the red and near-infrared region. In general, the current work provides a new and easy method for the large-scale preparation of gold-based uniform nanostructures, and offers an avenue to understand the interference of different plasmon modes in plasmonic systems, which has potential applications in surface science.

18.
Mikrochim Acta ; 187(4): 239, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32189141

RESUMO

In order to overcome the antibody-based sensor's shortcomings, an electrochemical aptamer (Apt)-based sensor was developed for amyloid-ß40 oligomer (Aß40-O). The aptasensor was constructed by locating Apt and ferrocence (Fc) on streptavidin-modified gold (SA-gold) nanoparticles. The obtained AptFc@SA-gold nanoparticles were linked onto the Au electrode via the connection of double-stranded DNA (dsDNA) as a "conductive spring." The determination of Aß40-O was performed with square-wave voltammetry (SWV). Upon bio-recognition between Apt and Aß40-O, the conformation of Apt changed and the formed Apt/Aß40-O complex separated from the SA-gold surface. As a result, the surface charge of SA-gold positively shifted, weakening the electrostatic attraction between the SA-gold and the positively charged Au electrode surface (at potential range of 0.1~0.5 V, corresponding to the Fc redox transformation), and stretching the dsDNA chain. Based on the exponential decay of dsDNA's electron transfer efficiency on its chain stretching, the oxidation current density from Fc decreased and displayed linear correlation to the concentration of Aß40-O. A wide linear range of 0.100 nM to 1.00 µM with a low detection limit of 93.0 pM was obtained. The aptasensor displayed excellent selectivity toward Aß40-O in contrast to other possible interfering analogs (Aß40 monomer, Aß42 monomer, and oligomer) at × 100 higher concentrations. The recoveries for Aß40-O-spiked artificial cerebrospinal fluid and healthy human serum were 94.0~104% and 92.8~95.4%, respectively. The electrochemical aptasensor meets the demands of clinic determination of Aß40-O, which is significant for the early diagnosis of AD. Graphical abstract Schematic representation of the electrochemical aptasensor for amyloid-ß oligomer based on the surface charge change induced by target binding.


Assuntos
Peptídeos beta-Amiloides/análise , Aptâmeros de Nucleotídeos/química , DNA/química , Técnicas Eletroquímicas/métodos , Doença de Alzheimer/diagnóstico , Técnicas Eletroquímicas/normas , Ouro , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Oxirredução
19.
Mikrochim Acta ; 187(9): 509, 2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32833087

RESUMO

A highly sensitive and specific surface plasmon resonance (SPR) method using one anti-alpha-synuclein antibody (anti-αS) and titanium phosphate nanoparticles (Ti4+@TiP) was developed for quantitative evaluation of phosphorylated αS level which was defined by the ratio of p-αS to total alpha-synuclein (t-αS) (p-αS/t-αS). The close affinities of anti-αS to αS (0.975 pM-1) and p-αS (0.938 pM-1) were obtained. Based on this fact , both αS forms were simultaneously captured and the t-αS was quantified using the anti-αS immobilized Au chip. With the selective recognition of Ti4+@TiP nanoparticles, the p-αS was quantified. The dynamic ranges of our method were 1.0~20.0 pg mL-1 for the detection of t-αS and 0.1~10.0 pg mL-1 for that of p-αS. The analysis of αS- and p-αS-spiked artificial cerebrospinal fluid samples revealed the high accuracy of the method. Furthermore, the concentrations of αS and p-αS in clinical CSF samples collected from three healthy donors were determined and displayed a high correlation with the results from a commercial ELISA kit, confirming the viability and of the proposed method. The method is convenient, economical, and practical for the evaluation of phosphorylated αS level with high sensitivity and selectivity. It is of great significance for the early diagnosis of PD and the evaluation of PD progression.Graphical abstract.


Assuntos
Nanopartículas Metálicas/química , Titânio/química , alfa-Sinucleína/líquido cefalorraquidiano , Anticorpos Imobilizados/imunologia , Humanos , Imunoensaio/métodos , Fosforilação , Ressonância de Plasmônio de Superfície/métodos , alfa-Sinucleína/química , alfa-Sinucleína/imunologia
20.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(2): 155-159, 2020 Feb 28.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-32386040

RESUMO

OBJECTIVES: To explore the therapeutic effect of myofascial trigger point electroacupuncture technology on treating female overactive bladder syndrome. METHODS: Forty female patients with overactive bladder were randomly divided into 2 groups: an experimental group and a control group. The experimental group was treated with myofascial trigger point electroacupuncture therapy combined with solifenacin succinate while the control group was only treated with solifenacin succinate. Patients in both groups were treated for 12 weeks. The overactive bladder symptom score (OABSS), urinary urgency score and urination frequency of 24 h in the 2 groups were compared to analyze the therapeutic effect. RESULTS: Before the comprehensive treatment, there was no significant difference between the experimental group and the control group (P>0.05). After 2 and 12 weeks of continuous treatment, the OABSS, urinary urgency symptoms score and 24 h urination frequency in the experimental group and the control group were lower than those before the treatment, and the degree of decline in the experimental group was more obvious, with significant difference (P<0.05). CONCLUSIONS: Treating overactive bladder syndrome in women with myofascial trigger point electroacupuncture combined with solifenacin succinate can significantly improve the OABSS and improve the life quality of the patients.


Assuntos
Eletroacupuntura , Bexiga Urinária Hiperativa , Feminino , Humanos , Qualidade de Vida , Succinato de Solifenacina , Resultado do Tratamento , Pontos-Gatilho
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