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.

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.

Application of ionic liquids in the microwave-assisted extraction of polyphenolic compounds from medicinal plants.

Ionic liquids (ILs) solutions as solvents were successfully applied in the microwave-assisted extraction (MAE) of polyphenolic compounds from medicinal plants. ILs, its concentration and MAE conditions were investigated in order to extract polyphenolic compounds effectively from Psidium guajava Linn. (P. guajava) leaves and Smilax china (S. china) tubers. The results obtained indicated that the anions and cations of ILs had influences on the extraction of polyphenolic compounds as well as the ILs with electron-rich aromatic pi-system enhanced extraction ability. Under the optimized conditions, the extraction yields of the polyphenolic compounds were in the range of 79.5-93.8% with one-step extraction, and meanwhile the recoveries were in the range of 85.2-103% with relative standard deviations (R.S.D.s) lower than 5.6%. Compared to conventional extraction procedures, the results suggested that the proposed method was effective and alternative for the extraction of polyphenolic compounds from medicinal plants. In addition, the extraction mechanisms and the structures of samples before and after extraction were also investigated. ILs solutions as green solvents in the MAE of polyphenolic compounds from medicinal plant samples showed a great promising prospect.

Study of vacuum microwave-assisted extraction of polyphenolic compounds and pigment from Chinese herbs.

Vacuum microwave-assisted extraction (VMAE), in which microwave-assisted extraction (MAE) was performed in vacuum, was specially designed and applied for the extraction of polyphenolic compounds and pigments from Chinese herbs. The extraction conditions including solid/liquid ratio, extraction time, extraction temperature and degree of vacuum were optimized. Subsequently, VMAE, MAE, and conventional heating reflux extraction (HRE) were evaluated with resveratrol and emodin extraction from Rhizma Polygoni Cuspidati, myricetin and quercetin extraction from Myrica rubra leaves, and safflomin A extraction from Flos Carthami. In addition, the different microstructures of those rhizome, leaf, and flower samples were investigated before and after extraction. It was obvious that the extraction yields of resveratrol, myricetin and safflomin A (thermosensitive compounds) with VMAE were higher than that with MAE or HRE by increments of 6.4-9.4% and 7.9-29.5%, respectively. In contrast, there was no obvious difference among the extraction yields for emodin and quercetin (thermo-stable compounds) with VMAE, MAE and HRE, except that the solvent consumption in VMAE was decreased. The results suggest that VMAE is a good alternative for the extraction of polyphenolic compounds and pigments, especially thermosensitive compounds, from Chinese herbs.

[Determination of cadmium, chromium and lead in Lycoris radiata with microwave digestion technique by graphite furnace atomic absorption spectrometry].

A new method using microwave digestion technique was developed for the determination of cadmium, chromium and lead in Lycoris radiata by graphite furnace atomic absorption spectrometry (GFAAS). Digestion solvents were discussed for sample preparation by microwave digestion technique. The optimum condition of determination by GFAAS was studied in the presence of NH4H2PO4 matrix modifier. The detection limits of Cd, Cr and Pb are 0.066 7, 1.22 and 0.810 microg x L(-1), respectively. The method was applied to the determination of Cd, Cr and Pb in Lycoris radiata samples with satisfactory results. The RSD of determination were lower than 3.1%. The recoveries were from 83.8% to 118%.

[Determination of organophosphorus pesticides in vegetables by microwave-assisted extraction/gas chromatography-mass spectrometry].

A method of microwave-assisted extraction (MAE) followed by gas chromatography-mass spectrometry (GC-MS) for the determination of organophosphorus pesticides (OPPs) in vegetables has been developed. The OPPs studied were diazinon, parathion and isocarbophos. Several extraction solvents were compared on the MAE efficiency. Dichloromethane gave good recovery, and was chosenfor the procedure. A three-level orthogonal array design was used to optimize the MAE process.Factors affecting the MAE efficiency were considered, including the solvent amount and extraction time.The linear ranges of the method were from 4 ng/g to 400 ng/g for diazinon and parathion, and from 20 ng/g to 400 ng/g for isocarbophos. The detection limits were 0.29 ng/g, 1.70 ng/g and 2.30 ng/g for diazinon, parathion and isocarbophos respectively. Two sets of spiked vegetable samples of 200.0 ng/g and 50.0 ng/g were determined. The recoveries were from 72.2% to 102.0%, and the RSDs were from 1.5% to 11.0% (n = 3). The analytical results agreed quite well with those obtained by conventional extraction with mechanical shaking (EMS). The method is fast and solvent-saving.