A simple yet powerful polymerase chain reaction (PCR)-free strategy for visualized assay of human telomerase activity was reported in this work. Gold nanoparticles (AuNPs) based colorimetric strategy ...was applied with well-designed enzyme-aided cyclic amplification. Briefly, the detection relies on the elongated primers of telomerase substrate (TS) induced by telomerase, which open the hairpin DNA and hybridize with linker DNA, the trigger of AuNPs aggregation. Nicking endonuclease was added in the sensing system, which cleaved linker DNA after hybridization and released complimentary strand for cyclic hybridization with linker DNA, resulted in high sensitivity for the detection of telomerase. Down to 25 HeLa cells with high expression of telomerase could be recognized. The proposed strategy provides a good platform for the determination of telomerase activity, differentiation of cancer cell lines from normal cell line and screening of telomerase-targeted anticancer drugs.
A novel DNA-AuNPs based colorimetric sensor is presented for the analysis of telomerase. With enzyme-aided cyclic amplification using nicking endonuclease, linker DNAs were largely consumed, which greatly enhanced the sensitivity of the method. The proposed PCR-free strategy doesn’t require complicated thermal-cycling procedure, which could be extended to a high-throughput clinical detection. Display omitted
•Gold nanoparticle based colorimetric sensor was constructed for visualized detection of telomerase activity.•The well-designed hairpin and linker DNAs ensured the reliability and specificity of the assay.•Enzyme-aided cyclic amplification greatly enhanced the sensitivity of the assay.•Cancer cell lines could be easily differentiated from normal cell line.•The efficiencies of telomerase-targeted anticancer drugs could be evaluated using this method.
A disposable paper-based bipolar electrode (BPE) was reported for the first time for the sensitive electrochemiluminescence detection of a prostate specific antigen (PSA).
Sensitive detection of severe fever with thrombocytopenia syndrome virus (SFTSV) by a point-of-care assay is of great significance for promoting clinical diagnosis. In this work, ultrasensitive ...detection of SFTSV was achieved by using fluorescent carbon dots/SiO2 nanospheres (CSNs) as reporters for a lateral flow assay. The prepared CSNs were resistant to extreme environments and had strong stability. The uniform CSNs with the size of about 200 nm were obtained by differential centrifugation. Their absolute quantum yields in the aqueous and solid phases are 56.3 and 36.6%, respectively. The excellent fluorescent properties of CSNs make the test strips more sensitive and have a longer assay lifetime. Thus, the visual detection limit of the lateral flow test strip based on immunofluorescent CSN (iCSN) was as low as 10 pg/mL SFTSV nucleoprotein. The sensitivity of this assay is 2 orders of magnitude higher than that of the colloidal gold-based lateral flow test strip. Besides, the assay owns good reproducibility and high specificity. Then, iCSN-based lateral flow test strips were evaluated in real samples of human serum of patients with satisfactory results. Furthermore, this assay has a general prospect for other fluorescent immunochromatography applications.
The presynaptic protein α-synuclein (αSyn) has been suggested to be involved in the pathogenesis of Parkinson’s disease (PD). In PD, the amygdala is prone to develop insoluble αSyn aggregates, and it ...has been suggested that circuit dysfunction involving the amygdala contributes to the psychiatric symptoms. Yet, how αSyn aggregates affect amygdala function is unknown. In this study, we examined αSyn in glutamatergic axon terminals and the impact of its aggregation on glutamatergic transmission in the basolateral amygdala (BLA). We found that αSyn is primarily present in the vesicular glutamate transporter 1-expressing (vGluT1
+
) terminals in the mouse BLA, which is consistent with higher levels of αSyn expression in vGluT1
+
glutamatergic neurons in the cerebral cortex relative to the vGluT2
+
glutamatergic neurons in the thalamus. We found that αSyn aggregation selectively decreased the cortico-BLA, but not the thalamo-BLA, transmission; and that cortico-BLA synapses displayed enhanced short-term depression upon repetitive stimulation. In addition, using confocal microscopy, we found that vGluT1
+
axon terminals exhibited decreased levels of soluble αSyn, which suggests that lower levels of soluble αSyn might underlie the enhanced short-term depression of cortico-BLA synapses. In agreement with this idea, we found that cortico-BLA synaptic depression was also enhanced in αSyn knockout mice. In conclusion, both basal and dynamic cortico-BLA transmission were disrupted by abnormal aggregation of αSyn and these changes might be relevant to the perturbed cortical control of the amygdala that has been suggested to play a role in psychiatric symptoms in PD.
This article is an example of Lessons from the Field highlighting the practical implementation of a novel time‐controlled mechanism in the gamification of emergency department evacuation training via ...tabletop exercise. Tabletop exercise is one of the most common drill types for disaster preparedness. It is easy to use, effective, and low in cost, but it has some shortcomings. For example, its lack of authenticity is often criticized. We add a time‐control mechanism to the tabletop exercise and use settings similar to real events in an attempt to increase the authenticity of the tabletop exercise and the learning effect. We completed a 3‐h tabletop gamification of emergency room evacuation, which included a time control mechanism. Medical staff in our emergency department were asked to join this tabletop training. We evaluated the effectiveness of the time‐control tabletop exercise through the results of the pretest and posttests and feedback from the participants. A total of 97 emergency medical staff from the Emergency Department of Cheng Kung University Hospital, including 64 nurses, 29 emergency doctors and four nurse practitioners, participated in this tabletop exercise. After experiencing the time‐control tabletop exercise, the participants significantly improved their approach to mass casualty incidents, their method for evacuating patients, and their triage skills. The correct answer rate for the pretest and post‐test rose from 68.75% to 94.33% with statistically significant. The feedback from the participants also showed that the time‐control tabletop exercise was interesting and could increase learning motivation. The time‐control mechanism had a positive impact on the learning effect. It increased the reality of tabletop exercises, promoted participants' learning motivation, and improved their performance on the test.
Hepatitis B virus (HBV) vaccination programs in Taiwan are one of the earliest programs in the world and have largely reduced the prevalence of HBV infection. We aimed to demonstrate the vaccination ...efficacy after 35 years and identify gaps toward HBV elimination.
A total of 4717 individuals aged 1-60 years were recruited from four administrative regions based on the proportion of population distribution. Serum levels of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were assessed. HBV viral load, genotypes and HBsAg 'ɑ' determinant variants were evaluated if indicated.
After 35 years of vaccination, the overall seropositivity rates for HBsAg and anti-HBc in Taiwan were 4.05% and 21.3%, respectively. The vaccinated birth cohorts exhibited significantly lower seropositivity rates for both markers compared to the unvaccinated birth cohorts (HBsAg: 0.64% vs. 9.78%; anti-HBc: 2.1% vs. 53.55%, respectively; p < 0.0001). Maternal transmission was identified as the main route of HBV infection in breakthrough cases. Additionally, increased prevalences of genotype C and HBsAg escape mutants were observed.
The 35-year universal HBV vaccination program effectively reduced the burden of HBV infection, but complete eradication of HBV infection has not yet been achieved. In addition to immunization, comprehensive screening and antiviral therapy for infected individuals, especially for pregnant women, are crucial strategies to eliminate HBV.
Electrochemical surface stress is important in nanomaterials because of their large surface‐to‐volume ratios, which lead to unique mechanical and electrocatalytic properties, but directly measuring ...this quantity has been challenging. Here we report on experimental determination of the surface stress, and associated electrochemical processes of a single gold nanowire with an optical imaging technique. We show that surface stress changes linearly and reversibly with the potential between 0 and 0.8 V versus Ag/AgCl, but abruptly with large hysteresis, associated with the oxidation and reduction of the nanowire, between 0.8 and 1.5 V. The potential derivative of the surface stress closely resembles the cyclic voltammograms. We described the observations in terms of anion adsorption and surface oxidation/reduction. This work demonstrates a new approach to study electrochemical processes and the associated surface stress changes of nanomaterials.
Gold nanowires under stress: The electric strain in individual gold nanowires was measured in response to electrochemically controlled charge‐induced changes in surface stress. The length change of a single nanowire can be monitored in situ while the potential of the nanowire is varied (see picture).
A CRISPR-associated nuclease that can promiscuously cleave RNAs enables a rapid and cheap test for the single-molecule detection and single-base discrimination of nucleic acids.
The roots of O. fragrans are also a valuable resource in addition to its flowers and fruits. In this study, the HPLC-MS/MS method used for analyzing the chemical constituents in O. fragrans roots ...extract was developed, which showed high sensitivity for both qualitative and quantitative analyses. Thirty-two compounds were first discovered in O. fragrans roots, one compound of which was reported for the first time. The simultaneous determination method for acteoside, isoacteoside, oleuropein and phillyrin was validated to be sensitive and accurate. Then it was applied to determine the content of bioactive components in O. fragrans roots from different cultivars. The content of oleuropein and phillyrin in the twelve batches was relatively stable, while the content of acteoside and isoacteoside varied greatly. Moreover, the therapeutic material basis and mechanism of O. fragrans roots exerting its traditional pharmacodynamics were analyzed by network pharmacology. The results showed that O. fragrans roots might be effective for the treatment of inflammation, cardiovascular diseases, cancer, and rheumatoid arthritis, which is consistent with the traditional pharmacodynamics of O. fragrans roots. This work can provide an analytical method for the comprehensive development of O. fragrans roots.
Bioactive components in O. fragrans roots extract were investigated by HPLC-MS/MS method, which was sensitive both in identification and quantitation. The therapeutic material basis and mechanism of O. fragrans root exerting its traditional pharmacodynamics were analyzed by network pharmacology. Display omitted
•36 compounds were identified and 32 components were firstly discovered in O. fragrans roots.•Network pharmacology was used for analysis of therapeutic material basis.•Simple, effective and sensitive HPLC-MS/MS was developed.•Bioactive components in O. fragrans roots was elucidated by MS/MS.
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