In situ monitoring of the plasmon catalytic reaction of p-nitroaniline at a gas-liquid-solid three phase interface.

Localized surface plasmon resonance (LSPR) is caused by the irradiation of light on a metal surface. Here we present a surface plasmon catalytic reaction at the gas-liquid-solid three phase interface. Electrochemical deposition was used to prepare Ag nanostructure/Cu mesh surface-enhanced Raman scattering (SERS) substrates. Surface wettability was adjusted by changing the processing time of the surfactant. Then a three-phase interface platform was constructed with good SERS performance and active surface plasmon catalytic capacity by droplet detection. At the gas-liquid-solid three phase interface, different oxygen supplies for the catalytic reaction were offered on surfaces with different wettability values. Thus, in this study, surface plasmon catalytic reaction of p-nitroaniline (PNA) was successfully in situ monitored and the reaction mechanism was explored. Otherwise, density functional theory (DFT) was used to calculate the Raman spectra and energy levels of the reactants and reaction products. Moreover, this work provides a new platform for monitoring the surface plasmon reaction at the gas-liquid-solid three-phase interface and contributes to the development of the study in the surface plasmon catalytic reaction field.

Paenibacillus assamensis in Joint Fluid of Man with Suspected Tularemia, China.

Paenibacillus assamensis is a bacterium usually found in warm springs. We detected P. assamensis in a man with suspected tularemia. The strain isolated from the man's knee joint fluid was identified as P. assamensis after analysis of a homologous sequence of the 16S rRNA gene.

A novel SERS sensor array based on AuNRs and AuNSs inverse-etching for the discrimination of five antioxidants.

Antioxidants play an important role in life health and food safety. Herein, an inverse-etching platform based on gold nanorods (AuNRs) and gold nanostars (AuNSs) for high-throughput discrimination of antioxidants was constructed. Under the action of hydrogen peroxide (H2O2) and horseradish peroxidase (HRP), 3,3',5,5'-tetramethylbenzidine (TMB) would be oxidized to TMB+ or TMB2+. HRP reacts with H2O2 to release oxygen free radicals, which then react with TMB. Au nanomaterials can react with TMB2+, at the same time, Au was oxidized into Au (I), leading to the etching of the shape. Antioxidants, with good reduction ability, would prevent the further oxidation of TMB+ to TMB2+. So the presence of antioxidants will prevent further oxidation while avoiding the etching of Au in the catalytic oxidation process, thereby achieved inverse etching. Distinctive surface enhanced Raman scattering (SERS) fingerprint of five antioxidants were obtained based on the differential ability to scavenge free radicals. Five antioxidants, including ascorbic acid (AA), melatonin (Mel), glutathione (GSH), tea polyphenols (TPP), and uric acid (UA) were successfully distinguished by using linear discriminant analysis (LDA), heat map analysis and hierarchical cluster analysis (HCA). The study exhibits an effective inverse-etching based SERS sensor array for the response of antioxidants, which has great reference value in the field of human disease and food detection.

Surface enhanced Raman scattering of adsorbates on Au-CsPbIBr2 perovskite-based nanocomposites: charge-transfer and electromagnetic enhancement.

In this study, perovskite-based nanocomposites as surface enhanced Raman scattering substrates were designed by physically sputtering Au nanoparticles onto fabricated all-inorganic CsPbIBr2 perovskite films, which provide much stronger SERS signals as compared to normal Au or perovskite substrates. Their synergism enhancement mechanisms and influence factors, including hybrid layer sequence, fabrication parameters and excitation source, are discussed. In addition, the prepared composite substrate exhibits excellent uniformity, reproducibility and time stability. This study promotes an easily prepared perovskite-based substrate for SERS-related applications and develops further understanding of molecule-semiconductor-noble metal nanostructure interfacial interactions.

A three-dimensional "turn-on" sensor array for simultaneous discrimination of multiple heavy metal ions based on bovine serum albumin hybridized fluorescent gold nanoclusters.

Traditional single sensor is designed based on the "lock-and-key" mode, which only relies on the most dominant interactions between the sensing element and the target. Although it exhibits high selectivity, there are challenges in detecting multiple analytes at the same time. Here, a sensor array with three sensing elements is developed to detect multiple heavy metal ions simultaneously and quickly. In our experiment, bovine serum albumin-encapsulated gold nanoclusters (BSA-AuNCs) were used as fluorescence probes and three different dopamine (DA) concentrations as nonspecific receptors. As we know, self-polymerized polydopamine (PDA) can quench part of the fluorescence of BSA-AuNCs. Upon the addition of the heavy metal ions, the diverse non-specific interactions between DA and heavy metal ions result in the difference in the number of the remaining PDA. Therefore it would lead to different degrees of fluorescence recovery behavior. This unique "turn-on" fluorescence response mode can be analyzed by linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA). Two-dimensional, three-dimensional and even four-dimensional mixed ions detection and quantitative detection have also been achieved. Moreover, by using this fluorescence array mode, heavy metal ions in tap water or blood samples can be detected.

Study on anatomical parameters of adult lumbar intervertebral disc and endplate based on CT / 中国骨伤

OBJECTIVE@#To provide basic data for clinical application and individualized design of lumbar disc prostheses by measuring the anatomical parameters of lumbar intervertebral discs and endplates in healthy adults with CT three-dimensional reconstruction technology.@*METHODS@#A retrospective analysis was performed on 200 males and 200 females with normal lumbar spine who were admitted to the imaging center or outpatient department of the Second Affiliated Hospital of Xinjiang Medical University from September 2019 to December 2020. The age ranged from 20 to 60 years old, with an average of (40.61±11.22) years old. The measurement segment was L1-S1 intervertebral disc, and the measurement indicators included the axial anteroposterior diameter and transverse diameter of the intervertebral disc, sagittal anterior, middle and posterior height, coronal left and right height, intervertebral space angle, and transverse and anteroposterior diameters of the upper and lower endplates of each vertebral body.@*RESULTS@#①In terms of gender, the anatomical parameters of L1-S1 disc axial diameter, transverse diameter, sagittal anterior, middle and posterior height, left and right coronal height and intervertebral space angle were all higher in males than in females(P<0.05), and the anatomical parameters of upper and lower endplates of L1-S1 vertebral body were higher in males than in females(P<0.001). ②In comparison of sagittal height of anterior, middle and posterior intervertebral discs, the sagittal height of L1-L5 intervertebral discs was middle-high > anterior-high > posterior-high(P<0.001), while that of L5S1 intervertebral disc was anterior-high > middle-high > posterior-high (P<0.001). ③In the comparison of left and right coronal height, there was no statistical significance in the left and right coronal height of L1-S1 disc between male and female(P>0.05). ④The L1-S1 intervertebral spaces angle between male and female increased with the increase of vertebral body segments. ⑤The anterior and posterior diameters and transverse diameters of upper and lower of L1-S1 vertebral bodies endplates were height in males than in females(P<0.001).@*CONCLUSION@#The results suggest that gender differences should be considered in the design of adult lumbar disc prostheses. The anatomical parameters of the lumbar intervertebral disc varied with the increase of the vertebral body sequence, suggesting that different anatomical parameters of the intervertebral disc should be considered in the design of the artificial intervertebral disc, and the changes in the height of the sagittal position suggest that the design of the intervertebral disc should be wedge-shaped.