Machine-learning-assisted SERS nanosensor platform toward chemical fingerprinting of Baijiu flavors.

A novel fingerprinting platform for multiplex detection of flavor molecules in Baijiu was developed by using a surface-enhanced Raman scattering (SERS) nanosensor array in combination with machine learning. The SERS sensors were constructed by core-shell Fe3O4@Ag nanoparticles modified with molecules carrying end-groups of hydroxyl, pyridyl, methyl, and amino, respectively, which interacted with flavors and led to changes in the sensors' spectra. All the Raman spectra acquired from the nanosensor array contacting with the sample were concatenated into a single SERS super-spectrum, representing the flavor fingerprint which was recognized through machine learning. Principal component analysis, support vector machine, and partial least squares were utilized to build classification and quantitation models for predictive analyses. The SERS nanosensor array was successfully used for fingerprinting ten typical flavors in Baijiu including four esters, three alcohols, and three acids, with an accuracy of 100%, linear detection ranges over two orders of magnitude, and limits of detection ranging from 3.45 × 10-3 mg/L of phenylethyl acetate to 1.21 × 10-2 mg/L of ethyl hexanoate. It was also demonstrated that satisfactory accuracies (recoveries) ranging from 96.2 to 104% and relative standard deviations ranging from 0.65 to 2.78% were obtained for the simultaneous quantification of 3-methylbutyl acetate and phenylethyl acetate in eighteen Baijiu samples of three flavor types including sauce flavor, strong flavor, and light flavor. Compared with the existing detection techniques, this chemical fingerprinting platform is easy to use, highly sensitive, and can perform multiplex detection, which has great potential for practical applications.

[Rapid determination of total phosphorus by ultrasonic assisted sample digestion-spectrum analysis].

Aiming at the technological shortage of national standard method for the determination of total phosphorus, a rapid determination method of total phosphorus based on ultrasonic assisted sample digestion-spectrum analysis was put forward, and the on-line analysis experiment system was designed. Relying on the experiment system, the experimental method and technology was studied. In view of the actual environmental water samples, contrast test experiment with the national standard method for determination method of total phosphorus was carried on. The experimental results showed that the digestion rate of ultrasonic assisted sample digestion using fenton reagents could reach 97%-100% in 13.5 minutes, and the determination method could complete one copy of sample analysis within 16 minutes. This determination method can solve national standard method's technical problems. All of this research work provides the important experimental basis and technical support for the development of the rapid on-line monitoring instrument for determination of total phosphorus.

Prognostic value of the systemic immune-inflammation index in critically ill elderly patients with hip fracture: evidence from MIMIC (2008-2019).

Background: The systemic immune-inflammation index (SII) showed an extensive link between immunological dysfunction and the activation of systemic inflammation. Several studies have confirmed the application of SII to orthopedic diseases. However, the significance of SII in critically ill elderly individuals with hip fracture who require intensive care unit (ICU) admission is not yet known. This study centered on exploring the relationship between SII and clinical outcomes among critically ill elderly hip fracture individuals. Methods: The study centered around elderly patients experiencing severe illness following hip fractures and requiring admission to the ICU. These patients from the MIMIC-IV database formed the basis of this study's cohort. We stratified them into quartiles according to their SII levels. The results involved the mortality at 30 days and 1 year post-admission. Then we employ Cox proportional hazards regression analysis as well as restricted cubic splines to explore the association between the SII and clinical results in critically ill elderly patients with hip fracture. Results: The study encompassed 991 participants, among whom 63.98% identified as females. Notably, the mortality rates attributed to any cause within 30 days and 1 year after hospitalization stood at 19.68 and 33.40%, respectively. The multivariate Cox proportional hazards model disclosed a significant correlation between an elevated SII and all-cause mortality. Following adjustments for confounding variables, individuals with a high SII showed a notable correlation with 30-day mortality [adjusted hazard ratio (HR), 1.065; 95% confidence interval (CI), 1.044-1.087; p < 0.001] and 1-year mortality (adjusted HR, 1.051; 95% CI, 1.029-1.074; p < 0.001). Furthermore, the analysis of restricted cubic splines demonstrated a progressive increase in the risk of all-cause death as the SII value rose. Conclusion: Among critically ill elderly patients with hip fracture, the SII exhibits a non-linear association that positively correlates with both 30-day and 1-year all-cause mortality rates. The revelation indicates that the SII may play a vital role in identifying patients with hip fractures who face an escalated risk of mortality due to any cause.

Cyclodextrin-induced phase transformation of cesium copper bromide perovskite.

Phase transformation represents a fascinating way to tune the structural and optical properties of metal halide perovskites. Macrocyclic cyclodextrin could trigger transformation of cesium copper bromide, driven by strong interactions of the macrocyclic hydroxyl groups with the perovskite cesium and bromide ions.

[Simultaneous detection of phenol and anionic surfactant in water based on continuous spectrum].

Phenol and anionic surfactant are important indices for water-quality. Based on improvement and optimization of standard methods (spectrophotometry) for the two indices, we integrated the respective two color-extractants into a composited reagent. Using a self-developed microspectrometer with a design of splitting behind and collection of continuous spectrum signal (340-770 nm) in real time, a compound detection system was constructed. This system could simultaneously detect phenol and anionic surfactant in water without chemical and spectral interferences, leading to great decreases in reagent amount and detection time. The detection limits for phenol and anionic surfactant are 0. 003 and 0.016 mg x L(-1), respectively. This method was applied to water-quality monitoring of real samples in comparison with standard methods, and the results indicated that its reproducibility (relative standard deviation, n=5) and accuracy (relative error to results by standard methods) were less than 5%, contenting with the related standard.

Catalytic microcapsules assembled from enzyme-nanoparticle conjugates at oil-water interfaces.

Involuntary association: Anionic beta-galactosidase enzymes associate with positively charged Au nanoparticles to produce reduced-charge conjugates, which assemble at oil-water interfaces to result in stable microcapsules (see picture). The microcapsules were formed quickly and showed high enzymatic activity, which makes them promising materials for biotechnology applications.

Higher quantum efficiency and moisture resistance of all-inorganic halide perovskite nanocrystal films in situ fabricated with cyclodextrin.

Supermolecule ß-cyclodextrin was used to assist CsPbBr3 film fabrication. In situ growth of nanocrystals was effectively confined through strong interactions between perovskite Pb2+ ions and ß-CD hydroxyl groups, producing a compact and smooth film. The quantum efficiency achieved was 85.3% with a moisture resistance over months, exceeding the record of perovskite films.

Disruption of HepG2 cell adhesion by gold nanoparticle and Paclitaxel disclosed by in situ QCM measurement.

Cell adhesion is a crucial issue for cytotoxicity or anticancer effectiveness for tumor cells. However, how both nanoparticles and drugs affect cell adhesion has not yet been defined. Herein, we report for the first time that gold nanoparticles and Paclitaxel can disrupt adhesion, as well as enhance apoptosis of HepG2 cell individually and synergistically, as observed by in situ measurement using quartz crystal microbalance (QCM). It was also found by MTT assay that gold nanoparticles of low cellular cytotoxicity enhance the antiproliferation and apoptosis of HepG2 cell induced by Paclitaxel. Those findings would be of great potential for biomedical application of nanoparticles.

Exploration of organic-inorganic hybrid perovskites for surface-enhanced infrared spectroscopy of small molecules.

The organic-inorganic hybrid perovskites efficiently enhance the infrared absorption of small molecules. It is suggested that the quantum wells of perovskites enable the electrons of the perovskites to be excited by light in the infrared region. The exploration has opened a new path for chemical sensing through infrared spectroscopy.

Plasmonic swings during the Fenton reaction: catalytic sensing of organics in water via fullerene-decorated gold nanoparticles.

Fullerene-decorated gold nanoparticles were used to catalyse the Fenton reaction and the electron transfer cycle of the catalyst shifts the gold surface plasmon resonance back and forth. The plasmonic swing frequency is in accord with the redox reaction rate and could be applied for detection of organics in water.