Polydopamine modified colloidal gold nanotag-based lateral flow immunoassay platform for highly sensitive detection of pathogenic bacteria and fast evaluation of antibacterial agents.

Bacterial infection is a great threat to human health. Lateral flow immunoassays (LFIAs) with the merits of low cost, quick screening, and on-site detection are competitive technologies for bacteria detection, but their detection limits depend on the optical performance of the adopted nanotags. Herein, we presented a LFIA platform for bacteria detection using polydopamine (PDA) functionalized Au nanoparticles (denoted as Au@PDA) as the nanotag. The introduction of PDA could provide enhanced light absorption of Au, as well as numerous functional groups for conjugation. Small recognition molecules i.e. vancomycin (Van) and p-mercaptophenylboronic acid (PMBA) were covalently anchored to Au@PDA, and selected as the specific probes towards Gram-positive (G+) and Gram-negative (G-) bacteria, respectively. Taken Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) as the representative targets of G+ and G- bacteria, two LFA strips were successfully constructed based on the immuno-sandwich principle. They could quantitatively detect S. aureus and E. coli both down to 102 cfu/mL, a very competitive detection limit in comparison with other colorimetric or luminescent probes-based LFIAs. Furthermore, the proposed two strips were applied for the quantitative, accurate, and rapid detection of S. aureus and E. coli in food and human urine samples with good analytical results obtained. In addition, they were integrated as a screening platform for quick evaluation of diverse antibacterial agents within 3 h, which is remarkably shortened compared with that of the two traditional methods i.e. bacterial culture and plate-counting.

Potential role of blood pressure variability and plasma neurofilament light in the mechanism of comorbidity between Alzheimer's disease and cerebral small vessel disease.

INTRODUCTION: Long-term blood pressure variability (BPV) and plasma neurofilament light (pNfL) have been identified as potential biomarkers for Alzheimer's disease (AD) and cerebral small vessel disease (CSVD). However, the relationship between BPV, pNfL, and their association with the comorbidity of AD and CSVD remains unknown. METHODS: Participants with normal cognition and mild cognitive impairment from the Alzheimer's Disease Neuroimaging Initiative study were included in the data analysis. Linear mixed-effects regression models and causal mediation analyses were conducted to investigate the relationship among BPV, pNfL, comorbidity-related brain structural changes (hippocampal atrophy and white matter hyperintensities [WMH]), and cognitive function. RESULTS: BPV was associated with pNfL, volumes of hippocampus and WMH, and cognition. pNfL mediated the effects of BPV on brain structural changes and cognition. DISCUSSION: Our findings suggest a potential role of BPV and pNfL in the mechanism of comorbidity between AD and CSVD, underscoring the importance of BPV intervention in the general population. HIGHLIGHTS: Individuals with both Alzheimer's disease (AD) and cerebral small vessel disease (CSVD) pathologies had elevated blood pressure variability (BPV) and plasma neurofilament light (pNfL). The association between different components of BPV and brain structural changes may vary. BPV was associated with pNfL levels independent of average blood pressure. pNfL mediated the effects of BPV on comorbidity-related brain structural changes and cognitive performance.

Covalently hybridized carbon dots@mesoporous silica nanobeads as a robust and versatile phosphorescent probe for time-resolved biosensing and bioimaging.

Phosphorescence analyses have attracted broad attention due to their remarkable merits of the elimination of auto-fluorescence and scattering light. However, it remains a great challenge to develop novel materials with uniform size and morphology, stability, long lifetime, and aqueous-phase room temperature phosphorescence (RTP) characteristics. Herein, monodisperse and uniform RTP nanobeads were fabricated by an in situ covalent hybridization of carbon dots (CDs) and dendritic mesoporous silicon nanoparticles (DMSNs) via silane hydrolysis. The formation of Si-O-C and Si-C/N covalent bonds is beneficial for the fixation of vibrations and rotations of the luminescent centers. Specially, the nanopores of DMSNs provide a confined area that can isolate the triplet state of CDs from water and oxygen and thus ensure the occurrence of aqueous-phase RTP with an ultra-long lifetime of 1.195 s (seen by the naked eye up to 9 seconds). Through surface modifying folic acid (FA), CDs@DMSNs can serve as a probe to distinguish different cell lines that feature varying FA receptor expression levels. In addition, taking MCF-7 as the model, highly sensitive and quantitative detection (linear range: 103-106 cells per mL) has been achieved via an RTP probe. Furthermore, their potential applications in cellular and in vivo time-gated phosphorescence imaging have been proposed and demonstrated, respectively. This work would provide a new route to design CD-based RTP composites and promote their further applications in the medical and biological fields.

The Association of Body Mass Index with Cognition and Alzheimer's Disease Biomarkers in the Elderly with Different Cognitive Status: A Study from the Alzheimer's Disease Neuroimaging Initiative Database.

Background: The association of body mass index (BMI) with cognition and Alzheimer's disease (AD) biomarkers of the elderly remains inconclusive. Objective: To investigate the relationship between BMI and cognition as well as AD biomarkers in the elderly with different cognitive status. Methods: Participants with cognitively normal (CN) were included as the CN group. Participants with mild cognitive impairment and mild dementia were included as the cognitive impairment (CI) group. The relationship between BMI and AD biomarkers (cerebrospinal fluid Aß42 and p-tau181, hippocampal volume [HV]), global cognition (Mini-Mental State Examination [MMSE]), memory, and executive function were explored. Results: In the CI group, BMI was associated with MMSE (ß= 0.03, p = 0.009), Aß42 (ß= 0.006, p = 0.029), p-tau181/Aß42 ratio (ß= -0.001, p = 0.011), and HV (ß= 0.05, p < 0.001). However in the CN group, BMI exhibited associations with p-tau181 (ß= 0.012, p = 0.014) and memory composite score (ß= -0.04, p = 0.038), but not with p-tau181/Aß42 ratio and HV. Moreover, mediation analysis showed that in the CI group, the positive effect of BMI on HV and MMSE score was partially mediated by diastolic blood pressure. Conclusion: The association of BMI with cognition and AD biomarkers varies across different cognitive status. In particular, a lower BMI was associated with worse cognition, higher Aß burden, and lower HV in individuals with CI. Clinical practice should strengthen the monitoring and management of BMI in patients with AD.

Simultaneous Sensing of Velocity and Position of a Moving Light Source Using Metal-Insulator-Semiconductor Structures.

Photodetectors based on semiconductor devices have been widely used to sense light position, intensity, and wavelength. However, monitoring the motion velocity of a light beam generally requires complex integration of device arrays. Here, we report a single device of a simple metal-insulator-semiconductor structure for self-powered sensing not only position but also velocity of a light beam or shadow. A velocity-dependent voltage output between two terminals of the metal is observed. It is attributed to light illumination-induced local surface potential change in semiconductors and the following movement of local charges accumulated in the metal due to capacitive coupling. The amplitude of the velocity-dependent voltage can be facilely modulated by applying a gate voltage. These results shed light on compact devices with multiple sensing functions.

Changes in depressive symptoms before and after the first stroke: A longitudinal study from China Family Panel Study (CFPS).

OBJECTIVES: The study sought to examine the impact of longitudinal changes in depressive symptoms in middle-aged adults before and after their first stroke, and the impact of different ages. METHODS: The study monitored middle-aged patients with a first stroke in the China Family Panel Study (CFPS) survey from 2016 to 2020. This study examined longitudinal changes in depressive symptoms in middle-aged adults and their controls before and after stroke using multilevel models, and also explored factors influencing middle-aged adults at the time of their respective stroke and depressive symptoms using conditional regression models and stepwise regression models, respectively. A chi-square test was used to determine whether long-term changes in depressive symptoms in patients before and after stroke could be attributed to changes in a single depressive symptom. RESULTS: The study identified 582 first-time stroke patients and 5522 controls from a population of 17,588 participants. Middle-aged populations may have an increased risk of depressive symptoms after a first stroke compared to older populations. First-time stroke victims showed increased severity of depressive symptoms in both the two years before and the two years after stroke when depressive symptoms were assessed. Differences in the presentation of a single depressive symptom were most pronounced in sleep-related symptoms. CONCLUSIONS: The link between first stroke and changes in the trajectory of increased depressive symptoms is complex and bidirectional. Age is an important factor influencing changes in depressive symptoms, some attention should be paid to the middle-aged population. Special attention should also be paid to sleep-related symptoms in the long-term care of patients.

Association between internal migration experience and depressive symptoms: analysis of PSID data.

BACKGROUND: Depression is on the rise globally. Additionally, the United States has a high level of population mobility. The main aim of this study was to provide a reference for improving the mental health of internal migrants by investigating the relationship between internal migration experience and depressive symptoms. METHODS: We analysed data from the Panel Study of Income Dynamics (PSID). We included PSID data from the 2005 to 2019 waves in which all respondents were asked about their internal migration experience and depressive symptoms. This study included 15,023 participants. T tests, chi-square tests, multiple logistic regression methods were performed and fixed effects model. RESULTS: In the sample, the prevalence of depressive symptoms was 4.42%. The risk of depression in internal migrants was 1.259 times (OR = 1.259, 95% CI = (1.025-1.547, p < 0.05) that of nonmigrants. Internal migration experience was significantly positively associated with female depressive episodes (OR = 1.312, 95% CI = 1.010-1.704, p < 0.05) and increased risk of becoming depressed at a young age (OR = 1.304, 95% CI = 1.010-1.684, p < 0.05). The association between internal migration experience and depressive symptoms was more significant for participants who might move (OR = 1.459, 95% CI = 1.094-1.947, p < 0.05). In addition, different internal migratory causes are associated with depressive symptoms to varying degrees. CONCLUSIONS: Our findings highlight the need for greater policy attention to mental health inequalities between Internal migrants and those who never move away from their hometown in the United States. Our study provides a foundation for further research.

Guiding-mode-assisted double-BICs in an all-dielectric metasurface.

The electromagnetically induced transparency (EIT) effect realized in a metasurface is potential for slow light applications for its extreme dispersion variation in the transparency window. Herein, we propose an all-dielectric metasurface to generate a double resonance-trapped quasi bound states in the continuum (BICs) in the form of EIT or Fano resonance through selectively exciting the guiding modes with the grating. The group delay of the EIT is effectively improved up to 2113 ps attributing to the ultrahigh Q-factor resonance carried by the resonance-trapped quasi-BIC. The coupled harmonic oscillator model and a full multipole decomposition are utilized to analyze the physical mechanism of EIT-based quasi-BIC. In addition, the BIC based on Fano and EIT resonance can simultaneously exist at different wavelengths. These findings provide a new feasible platform for slow light devices in the near-infrared region.

Color change of glass ceramic restorations cemented by four types of dual-cured resin luting agents with different initiator systems.

This study aimed to comprehensively evaluate the effect of dual-cured resin luting agents with different initiator systems on the color stability of glass ceramic restorations by simulating various clinical glass ceramic restorations. Three commonly used shades from each of the two dual-cured resin luting agents with an amine-initiation system or without it were studied. The individual specimens had different translucency and thickness and were artificially aged using a xenon light aging machine. The color was measured before and after aging using a digital spectrophotometer with the difference calculated and analyzed statistically. As results, the amine-free dual-cured resin luting agents were more color stable than those using amine-initiation systems for both uncovered and bonding groups. The translucency and thickness of the ceramic, and shade and type of the resin luting agent significantly affected the color stability of glass ceramic restorations.

Research progress on the methods of observation and analysis of dental bonding interfaces / 口腔疾病防治

@#Dental bonding technology and materials have been used widely in dentistry because of their excellent properties. The development of novel bonding technology and materials is constantly being performed to improve the effect of dental bonding restorations. Observation and analysis of the dental bonding interface is one of the most important methods for laboratory evaluation of bonding efficiency. This paper aims to review the methods of observation and analysis of dental bonding interfaces to provide a reference for the selection of evaluation methods in dental bonding research. The features of 6 methods, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), Raman spectroscopy (RS), optical coherence tomography (OCT) and atomic force microscopy (AFM), were described and summarized. Among these methods, SEM and TEM are used most often in the analysis of fine structures; CLSM and OCT are used for the acquisition of characteristic image signals, such as microleakage and exogenous and endogenous fluorescence; and RS and AFM can test chemical composition and mechanical properties.

Selective 1,2-Aryl-Aminoalkylation of Alkenes Enabled by Metallaphotoredox Catalysis.

A highly chemo- and regioselective intermolecular 1,2-aryl-aminoalkylation of alkenes by photoredox/nickel dual catalysis is described here. This three-component conjunctive cross-coupling is highlighted by its first application of primary alkyl radicals, which were not compatible in previous reports. The readily prepared α-silyl amines could be transferred to α-amino radicals by photo-induced single electron transfer step. The radical addition/cross-coupling cascade reaction proceeds under mild, base-free and redox-neutral conditions with good functional group tolerance, and importantly, provides an efficient and concise method for the synthesis of structurally valuable α-aryl substituted γ-amino acid derivatives motifs.