[Recent advances in the development and application of effervescence-assisted microextraction techniques].

Effervescence-assisted microextraction (EAM) is a novel sample pretreatment method based on the reaction of CO2 and H+ donors to generate CO2 bubbles and promote rapid dispersion of the extractant. During this process, the unique dispersion method increases the contact area between the target molecule and the extraction solvent, and the adsorption/extraction efficiency of the adsorbent/extractant toward the target molecule is also enhanced. The EAM technique is of particular interest due its convenient application, low running costs, reduced solvent consumption, high extraction efficiency, and environmental friendliness. Benefiting from the rapid development of extractants, the evolution and application of the EAM technology is becoming more tuned and diversified. Indeed, the synthesis of new extractants, such as nanomaterials with multi-pore structures, large specific surface areas, and rich active sites, has attracted extensive attention, as has the development of ionic liquids with strong extraction abilities and high selectivities. As a result, the EAM technology has been widely applied to the pretreatment of target compounds in various samples, such as food, plant, biological, and environmental samples. However, since these samples often contain polysaccharides, peptides, proteins, inorganic salts, and other interfering substrates, it is necessary to remove some of these substances prior to extraction by EAM. This is commonly achieved using methods such as vortexing, centrifugation, and dilution, among others. The treated samples can then be extracted using the EAM method prior to detection using high performance liquid chromatography (HPLC), gas chromatography (GC), and atomic absorption spectroscopy (AAS) to detect substances such as heavy metal ions, pesticide residues, endocrine-disrupting compounds (EDCs), and antibiotics. Using effervescence as a novel assisted method for the dispersion of solvents or adsorbents, the concentrations of Pb2+, Cd2+, Ni2+, Cu2+, bisphenol, estrogen, and the pyrethyl pesticides have previously been successfully determined. Moreover, many influencing factors have been evaluated during method development, including the composition of the effervescent tablet, the solution pH, the extraction temperature, the type and mass/volume of extractant, the type of eluent, the eluent concentration, the elution time, and the regeneration performance. Generally, the cumbersome single factor optimization and multi-factor optimization methods are also required to determine the optimal experimental conditions. Following determination of the optimal experimental conditions, the EAM method was validated by a series of experimental parameters including the linear range, the correlation coefficient (R2), the enrichment factor (EF), the limit of detection (LOD), and the limit of quantification (LOQ). In addition, the use of this method has been demonstrated in actual sample testing, and the obtained results have compared with those achieved using similar detection systems and methods to ultimately determine the accuracy, feasibility, and superiority of the developed method. In this paper, the construction of an EAM method based on nanomaterials, ionic liquids, and other emerging extractants is reviewed, wherein the preparation method, application range, and comparison of similar extractants were evaluated for the same extraction system. In addition, the current state-of-the-art in relation to EAM research and application when combined with HPLC, cold flame AAS, and other analytical techniques is summarized in terms of the detection of harmful substances in complex matrices. More specifically, the samples evaluated herein include dairy products, honey, beverages, surface water, vegetables, blood, urine, liver, and complex botanicals. Furthermore, issues related to the application of this technology are analyzed, and its future development trend in the field of microextraction is forecasted. Finally, the application prospects of EAM in the analysis of various pollutants and components are proposed to provide reference for monitoring pollutants in food, environmental, and biological samples.

[Application of the vanillin sulfuric acid colorimetry-ultraviolet spectrometry on quality evaluation of Panax notoginseng].

In this study, Panax notoginseng samples were extracted by chloroform, ethanol and water, or by those extracted solution with 5% vanillin sulfuric acid to establish two kinds of UV fingerprint of P. notoginseng which were compared by applying the common and variation peak ratio dual index sequence analysis method and SIMCA software qualitative analysis. The results indicated that the optimization extraction time of P. notoginseng samples was 20 min with chloroform, ethanol and water extraction, but the fingerprint differed significantly after add vanillin sulfuric acid. The common peak ratios of UV fingerprint of P. notoginseng were scattered. The minimum was 25% (Y5-Y8), while the maximum was 84.38% (Y11-Y13, Y20-Y21). The maximum variation peak ratio was 177.78% (Y8-Y5), meanwhile, the variation peak ratios of several samples were more than 100%. However, the common peak ratios of UV fingerprint of P. notoginseng with vanillin sulfuric acid were concentrated (distributed in the range of 50%-70%): the minimum was 42.86%(Y1-Y19), whereas the maximum was 79.55% (Y22-Y23); the range of the variation peak ratios was also smaller with the ranges of 20%-50% in general. The result of the dual index sequence analysis was agreement with the fingerprint implied. The similarity of the UV fingerprint of the extracts of P. notoginseng after adding vanillin sulfuric acid was greater than before. Both the ages and origin was related with the difference of UV fingerprint. The similarity of the two samples with same age was more significant than those with different ages. The similarity and difference between samples was no correlation with the distance of geographic space, the near origin samples maybe have a significant similarity or difference. This method appears as good alternative for evaluate quality of the P. notoginseng and can distinguish at least two samples quantitatively, duo to it reaches the limitation of the multiple methods which only could be used to indistinctly distinguish herbs.

[Clinical evaluation of the antioxidant activity of astragalus in women with gestational diabetes].

OBJECTIVE: To evaluate the antioxidant activity of astragalus and its therapeutic effect on gestational diabetes. METHODS: Eighty-four pregnant women with gestational diabetes were divided into insulin and insulin plus astragalus groups after regular dietary control and insulin treatment to maintain stable blood glucose level. The 43 patients in insulin group received insulin injection, whereas the 41 patients in the other group received treatment with both insulin and astragalus. The SOD activity, MDA level, blood lipids and renal function were determined in both groups after the treatments. RESULTS: The patients with both insulin and astragalus treatments showed significantly increased serum SOD activity and decreased MDA level, renal function and blood lipids in comparison with those with exclusive insulin treatment. CONCLUSION: Astragalus can effectively control blood glucose, reduce the free radicals, and promote the antioxidative activity, and may play a role in the prevention and treatment of gestational diabetes.

Effect of polylactic acid glue in preventing epidural scar adhesion after laminectomy in rabbits.

OBJECTIVE: To determine the efficacy of polylactic acid glue in preventing epidural scar adhesion after laminectomy in rabbits. METHODS: Twenty-four Japanese white rabbits underwent laminectomy (including the attached ligaments) at L(2 ) and L(5). After laminectomy at L(5), polylactic acid glue was sprayed on the dura and nerve roots and this segment was taken as the experimental group. After laminectomy at L(2), nothing was used and this segment was enrolled as the self control group. Four rabbits were killed every two weeks postoperatively till the end of the experiment at 12 weeks. Then the operated spine was observed grossly, histologically and ultrastructurally to check the degree of scar formation, the status of epidural scar adhesion, the absorption of the glue, and the intracellular structure of fibroblasts. RESULTS: The glue coagulated immediately after spraying and showed excellent hemostatic effect. The glue membrane was easy to be taken away from the dura mater of the samples for 2 weeks and there were no cells in the epidural space in the experimental group. But the dura mater was covered by hematoma in the control group, which formed mild adhesion, with fibroblasts proliferating actively. In the 4th week, some glue shivers remained in the epidural space with fibroblasts increasing a little, and the dura mater was smooth in the experimental group. However, in the control group, the formed scar was fragile and conglutinated with the dura mater diffusely and fibroblasts were much more than those in the experimental group. In the 6th-12th weeks, there was a potential interspace between the scar and the dura mater, and the polylactic acid glue was absorbed completely in the experimental group. Much tough scar was found in the control group, which was very difficult to dissect from the dura mater and the surrounding tissues. From the ultrastructural observation of the fibroblasts, the nucleus became much bigger and the rough endoplasmic reticulum was much more plentiful in the control group than that in the experimental group. CONCLUSIONS: Polylactic acid glue can effectively reduce epidural cicatrization and adhesion.

[Function of fibula in stability of ankle joint].

OBJECTIVE: To summarize the function of fibula in stability of ankle joints. METHODS: Recent original articles were extensively reviewed, which were related to the physiological function and biomechanical properties of fibula, the influence of fibular fracture on stability of ankle joints and mechanism of osteoarthritis of ankle joints. RESULTS: The fibula had the function of weight-bearing; and it was generally agreed that discontinued fibula could lead to intra-articular disorder of ankle joint in children; but there were various viewpoints regarding the influence of fibular fracture on the ankle joint in adults. CONCLUSION: Fibula may play an important role in stability of ankle joint.