[Surface-modified microchip electrophoretic separation and analysis of functional components in health care products].

Microchip electrophoresis (MCE) is widely applied in food, environment, medicine, and other fields, owing to its high separation efficiency, low consumption of reagents and samples, and ease of integrating multiple operating units. Polymer microchip materials like cycloolefin copolymer (COC) are low-cost and easy to fabricate. However, their practical applications are limited by the non-specific adsorption on channel surface during electrophoresis and the instability of electroosmotic flow. These shortcomings can be solved by COC surface modification. In this study, a static coating and dynamic/static coating combined strategy was used to develop a channel-surface-modified COC microchip. Combined with laser-induced fluorescence (LIF) detection, a MCE-LIF separation and analysis method was developed for detecting functional components in health care products. The separation performance of MCE was improved by the static coating microchannel surface modification method. The static coating was constructed by hydrophobic amino acid adsorption, glutaraldehyde immobilization, and hydrophilic amino acid functionalization on the COC microchannel surface. The separation performance of MCE was improved by microchannel surface modification combined with dynamic/static coating. The static coating was constructed by valine adsorption, carboxyl activation, and ethylenediamine functionalization on the COC microchannel surface. The dynamic coating is automatically formed by introducing a buffer solution containing hydroxypropyl methylcellulose and sodium dodecyl sulfate into the microchannel. The physical and chemical properties of surface-modified microchannels and the factors governing electrophoretic separation were studied. Combined with LIF detection, the MCE-LIF separation and analysis of lysine and γ-aminobutyric acid present in children's health care products, as well as aspartic acid and taurine in sport drinks, were developed. The recoveries of lysine and γ-aminobutyric acid in children's health care products were 84.8%-118%, and the relative standard deviations (RSDs) were less than 7.2% (n=3). The recoveries of aspartic acid and taurine in sport drinks were 97.5%-118%, and the RSDs were less than 6.4% (n=3). The analysis results are consistent with the HPLC results, and the method has potential for application in the separation and analysis of anionic amino acids in health care products.

[Advances in microchip electrophoresis for the separation and analysis of biological samples].

Microchip electrophoresis is a separation technology that involves fluid manipulation in a microchip; the advantages of this technique include high separation efficiency, low sample consumption, and fast and easy multistep integration. Microchip electrophoresis has been widely used to rapidly separate and analyze complex samples in biology and medicine. In this paper, we review the research progress on microchip electrophoresis, explore the fabrication and separation modes of microchip materials, and discuss their applications in the detection and analysis of biological samples. Research on microchip materials can be mainly categorized into chip materials, channel modifications, electrode materials, and electrode integration methods. Microchip materials research involves the development of silicon, glass, polydimethylsiloxane and polymethyl methacrylate-based, and paper electrophoretic materials. Microchannel modification research primarily focuses on the dynamic and static modification methods of microchannels. Although chip materials and fabrication technologies have improved over the years, problems such as high manufacturing costs, long processing time, and short service lives continue to persist. These problems hinder the industrialization of microchip electrophoresis. At present, few static methods for the surface modification of polymer channels are available, and most of them involve a combination of physical adsorption and polymers. Therefore, developing efficient surface modification methods for polymer channels remains a necessary undertaking. In addition, both dynamic and static modifications require the introduction of other chemicals, which may not be conducive to the expansion of subsequent experiments. The materials commonly used in the development of electrodes and processing methods for electrode-microchip integration include gold, platinum, and silver. Microchip electrophoresis can be divided into two modes according to the uniformity of the electric field: uniform and non-uniform. The uniform electric field electrophoresis mode mainly involves micro free-flow electrophoresis and micro zone electrophoresis, including micro isoelectric focusing electrophoresis, micro isovelocity electrophoresis, and micro density gradient electrophoresis. The non-uniform electric field electrophoresis mode involves micro dielectric electrophoresis. Microchip electrophoresis is typically used in conjunction with conventional laboratory methods, such as optical, electrochemical, and mass spectrometry, to achieve the rapid and efficient separation and analysis of complex samples. However, the labeling required for most widely used laser-induced fluorescence technologies often involves a cumbersome organic synthesis process, and not all samples can be labeled, which limits the application scenarios of laser-induced fluorescence. The applications of unlabeled microchip electrophoresis-chemiluminescence/dielectrophoresis are also limited, and simplification of the experimental process to achieve simple and rapid microchip electrophoresis remains challenging. Several new models and strategies for high throughput in situ detection based on these detection methods have been developed for microchip electrophoretic systems. However, high throughput analysis by microchip electrophoresis is often dependent on complex chip structures and relatively complicated detection methods; thus, simple high throughput analytical technologies must be further explored. This paper also reviews the progress on microchip electrophoresis for the separation and analysis of complex biological samples, such as biomacromolecules, biological small molecules, and bioparticles, and forecasts the development trend of microchip electrophoresis in the separation and analysis of biomolecules. Over 250 research papers on this field are published annually, and it is gradually becoming a research focus. Most previous research has focused on biomacromolecules, including proteins and nucleic acids; biological small molecules, including amino acids, metabolites, and ions; and bioparticles, including cells and pathogens. However, several problems remain unsolved in the field of microchip electrophoresis. Overall, microchip electrophoresis requires further study to increase its suitability for the separation and analysis of complex biological samples.

Effect of Early versus Delayed Use of Norepinephrine on Short-Term Outcomes in Patients with Traumatic Hemorrhagic Shock: A Propensity Score Matching Analysis.

Background: Guidelines recommend norepinephrine (NE) for the treatment of fatal hypotension caused by trauma. However, the optimal timing of treatment remains unclear. Objective: We aimed to investigate the effect of early versus delayed use of NE on survival in patients with traumatic haemorrhagic shock (HS). Materials and Methods: From March 2017 to April 2021, 356 patients with HS in the Department of Emergency Intensive Care Medicine of the Affiliated Hospital of Yangzhou University were identified using the emergency information system and inpatient electronic medical records for inclusion in the study. Our study endpoint was 24 h mortality. We used a propensity score matching (PSM) analysis to reduce bias between groups. Survival models were used to evaluate the relationship between early NE and 24 h survival. Results: After PSM, 308 patients were divided equally into an early NE (eNE) group and a delayed NE (dNE) group. Patients in the eNE group had lower 24 h mortality rates than those in the dNE group (29.9% versus 44.8%, respectively). A receiver operating characteristic analysis demonstrated that a cut-off point for NE use of 4.4 h yielded optimal predictive value for 24 h mortality, with a sensitivity of 95.52%, a specificity of 81.33% and an area under the curve value of 0.9272. Univariate and multivariate survival analyses showed that the survival rate of patients in the eNE group was higher (p < 0.01) than those in the dNE group. Conclusion: The use of NE within the first 3 h was associated with a higher 24 h survival rate. The use of eNE appears to be a safe intervention that benefits patients with traumatic HS.

Prediction of factors influencing the timing and prognosis of early tracheostomy in patients with multiple rib fractures: A propensity score matching analysis.

Objective: To investigate the factors affecting the timing and prognosis of early tracheostomy in multiple rib fracture patients. Methods: A retrospective case-control study was used to analyze the clinical data of 222 patients with multiple rib fractures who underwent tracheotomy in the Affiliated Hospital of Yangzhou University from February 2015 to October 2021. According to the time from tracheal intubation to tracheostomy after admission, the patients were divided into two groups: the early tracheostomy group (within 7 days after tracheal intubation, ET) and late tracheostomy group (after the 7th day, LT). Propensity score matching (PSM) was used to eliminate the differences in baseline characteristics Logistic regression was used to predict the independent risk factors for early tracheostomy. Kaplan-Meier and Cox survival analyses were used to analyze the influencing factors of the 28-day survival. Results: According to the propensity score matching analysis, a total of 174 patients were finally included in the study. Among them, there were 87 patients in the ET group and 87 patients in the LT group. After propensity score matching, Number of total rib fractures (NTRF) (P < 0.001), Acute respiratory distress syndrome (ARDS) (P < 0.001) and Volume of pulmonary contusion(VPC) (P < 0.000) in the ET group were higher than those in the LT group. Univariate analysis showed that the patients who underwent ET had a higher survival rate than those who underwent LT (P = 0.021). Pearson's analysis showed that there was a significant correlation between NTRF and VPC (r = 0.369, P = 0.001). A receiver operating characteristic(ROC)curve analysis showed that the areas under the curves were 0.832 and 0.804. The best cutoff-value values of the VPC and NTRF were 23.9 and 8.5, respectively. The Cox survival analysis showed that the timing of tracheostomy (HR = 2.51 95% CI, 1.12-5.57, P = 0.004) and age (HR = 1.53 95% CI, 1.00-2.05, P = 0.042) of the patients had a significant impact on the 28-day survival of patients with multiple rib fractures. In addition, The Kaplan-Meier survival analysis showed that the 28-day survival of patients in the ET group was significantly better than that of the LT group, P = 0.01. Conclusions: NTRF, ADRS and VPC are independent risk factors for the timing and prognosis of early tracheotomy. A VPC ≥ 23.9% and/or an NTRF ≥ 8.5 could be used as predictors of ET in patients with multiple rib fractures. Predicting the timing of early tracheostomy also need prediction models in the future.

[The Progress on Cataluminescence-Based Analytical System].

Cataluminescence (CTL) is a phenomenon of light radiation generated when analyte moleculars were oxidized by catalyst. In the past few decades, CTL has developed rapidly and become a promising detection technique, especially in gas sensing, and has attracted much attention of researchers for its potential versatile applications in emission control, public safety, and environmental protection. The analytical system based on CTL has low detection limit, high sensitivity and simple instrument which easy to operate, which shows huge advantages in the detection of inorganic gases and volatile organic compounds. The library of sensing materials has been greatly enriched to thousands kinds, which contains metals, metal/non-metal oxides, sulfide, metal salts, organic compounds, ceramic, glass and other types of materials; Composite materials have been developed; The decreasing of material dimensions to nanoscale provided new opportunities for its development; The morphology of material has also been explored. Some novel hyphenated techniques based on CTL coupled to other techniques including preconcentration/sepration, nebulization, plasma have been developed, as well as some new CTL technique including static CTL, cyclic CTL and ect. Thanks to development of sensing material and the appearance of these novel techniques, the selectivity and sensitivity of CTL system has been improved, and the range of CTL application has been extended. In this article, the progress made in the field of cataluminescence, especially in latest developments of analytical applications were reviewed. The catalysts used in CTL, the recent novel CTL techniques were sumerized. The future of the cataluminescence was also forecasted.

[Advance of Development and Application of GC-IR Technology].

The gas chromatograph (GC)-infrared spectroscopy (IR) technique combines the particular separating capacity of GC and the faultlessly with distinguishing capacity of molecular structure of IR, its detective sensitivity is very high and itis used to separate and identify many kinds of complicated compounds from element speciation analysis, natural products, and gasoline. This paper introduces the principle of GC-IR. Three types of interface techniques, light pipe technique, matrix isolation technique and direct deposition technique are compared. Connection type with other detections and factors influencing sensitivity in interface are also introduced. The improvement and achievement in coupling GC system, interface, data processing techniques and its application is reviewed in the present paper.

Separation and purification of steroidal saponins from Paris polyphylla by microwave-assisted extraction coupled with countercurrent chromatography using evaporative light scattering detection.

A method of microwave-assisted extraction coupled with countercurrent chromatography using evaporative light scattering detection was successfully developed for the separation and purification of steroidal saponins from Paris polyphylla. The main extraction conditions including microwave power, liquid/solid ratio, irradiation time, and extraction temperature were optimized using an orthogonal array design method. A suitable two-phase solvent system consisting of n-heptane/n-butanol/acetonitrile/water (10:19:6:20, v/v/v/v) was employed in the separation and purification of the extracts of P. polyphylla. A total of 7.1 mg polyphyllin VII, 4.3 mg gracillin, 9.2 mg dioscin, and 10.2 mg polyphyllin I were obtained from 1.5 g P. polyphylla in less than 300 min, the purities of which determined by HPLC were 96.7, 97.3, 98.7, and 98.6%, respectively. The identification and characterization of these compounds were performed by LC-ESI-MS and 1H NMR spectroscopy. The results demonstrated that the proposed method is feasible, economical and efficient for the extraction, separation and purification of effective compounds from natural products.

Microwave-assisted extraction coupled with countercurrent chromatography for the rapid preparation of flavonoids from Scutellaria barbata D. Don.

As a famous Chinese herb having good inhibitory effects on numerous human cancers both in vitro and in vivo, Scutellaria barbata D. Don attracts extensive attention worldwide. In this work, four flavonoids named scutellarin, baicalin, luteolin, and apigenin were simply and rapidly prepared from S. barbata by microwave-assisted extraction coupled to countercurrent chromatography. Extraction conditions including irradiation time, extraction temperature, liquid/solid ratio, and microwave power were optimized using an orthogonal array design method. The extract of S. barbata was separated and purified with a two-phase solvent system composed of hexane/ethyl acetate/methanol/acetic acid/water (1:5:1.5:1:4, v/v/v/v/v) and 4.5 mg of scutellarin, 4.6 mg of baicalin, 1.1 mg of luteolin, 2.1 mg of apigenin were obtained from 2.0 g original sample in a single run. The purities of scutellarin, baicalin, luteolin, and apigenin determined by HPLC were 93.6, 97.3, 97.6, and 98.4%, respectively. The targeted compounds were identified by LC with MS and (1) H NMR spectroscopy. The total time including extraction, separation, and purification was <300 min. Compared to traditional methods, microwave-assisted extraction coupled to countercurrent chromatography method is more simple and rapid for the extraction, separation, and purification of flavonoid compounds from natural products.

A novel luminol-based chemiluminescence method for the determination of amikacin sulfate in serum by using trivalent copper-periodate complex.

A novel chemiluminescence (CL) reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex (K5[Cu(HIO6)2], DPC) in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate (AKS). A new CL method was developed for the determination of AKS by coupling with flow injection (FI) technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10-7 M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0×10-9-4.0×10-6 g/mL with the detection limit of 1.2×10-9 g/mL. The relative standard deviation was 2.1% for 8.0×10-9 g/mL AKS (n=9). The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC.

[A novel flow injection chemiluminescence method with ferricyanide and luminol for the determination of ractopamine in biological samples].

A novel chemiluminescence method coupled with flow injection technique for the determination of ractopamine was developed. It was based on the enhancement of the chemiluminescence by ractopamine derived from the chemiluminescence reaction between luminol and ferricyanide in sodium hydroxide medium. The linear calibration range of the chemiluminescence intensity with respect to the ractopamine concentration covers from 4.0 x 10(-9) - 8.0 x 10(-7) g x mL(-1). The relative standard deviation for ractopamine is 5.6% (n = 11), and the detection limit is 2.5 x 10(-9) g x mL(-1). The method was firstly applied to the determination of ractopamine in biological samples with satisfactory results. The recovery was between 69.3% and 101.3%.