[Hologram quantitative structure-activity relationship on the gas chromatographic retention index of plant essential oil constituents].

The gas chromatography retention index (RI) is an important parameter for the identification of different types of compounds in the field of chromatographic analysis; however, the experimental collection of RI values is a extremely cumbersome process. Thus, there is an urgent need for the establishment of a simple, efficient, and accurate model for the prediction of the RI values of compounds. In this study, first, the experimental RI values for 60 plant essential oil constituents were obtained. Next, a model describing the hologram quantitative structure-activity relationship (HQSAR) between the structural properties of the essential oil constituents and their RI values was investigated and constructed. The optimal HQSAR model was established by setting the model parameters "fragment size", "fragment distinction", "hologram length" and "principal components" to "1-4", "C, Ch", "199", and "4", respectively. Finally, the predictive ability of the model was verified using external test set validation and leave-one-out cross-validation (LOO-CV). The experimental results were as follows, the root mean square error of prediction (RMSEP), predictive determination coefficient ([Formula: see text]), concordance correlation coefficient (CCC), and mean relative error (MRE) for external test set validation were 40.45, 0.984, 0.968, and 2.20%, respectively. Meanwhile, the root mean square error of cross validation (RMSECV) and MRE for LOO-CV were 72.56 and 4.17%, respectively. These findings demonstrate that the established HQSAR model has a good predictive ability and can accurately predict the RI values of plant essential oil constituents. In addition, the molecular contribution maps of the HQSAR model revealed that the RI values of aromatic compounds increase when hydroxyl groups are connected to their alkyl chains. Aliphatic compounds feature long chain alkyl groups, which can lead to an increase in RI values. The above phenomena highlight the promising application prospects of HQSAR for studying the RI values of plant essential oil constituents. Therefore, this study provides a reliable theoretical basis for predicting the RI values of other essential oil constituents.

[Association between levels of thyroid-stimulating hormone and prognosis of patients admitted to intensive care units: an analysis using the MIMIC-III].

OBJECTIVE: To explore the association between levels of thyroid-stimulating hormone (TSH) on admission and prognosis of patients admitted to intensive care unit (ICU). METHODS: The data were collected from patients who were admitted to the ICU of the Beth Israel Deaconess Medical Center in the United States from 2001 to 2012 with available TSH test records within 24 hours after the ICU admission via the Medical Information Mart for Intensive Care-III v1.4 (MIMIC-III v1.4). Information including gender, age, ethnicity, type of admission, mechanical ventilation (MV) or renal replacement therapy (RRT) received on admission, comorbidities, and TSH test records within 24 hours after the ICU admission were collected. The sequential organ failure assessment (SOFA) score, simplified acute physiology score II (SAPS II) and the comorbidities index Elixhauser (SID30) score were calculated according to the parameters. The primary outcome was hospital mortality. Differences in baseline characteristics and prognosis were examined between patients with normal TSH levels and abnormal TSH levels which was determined according to a dichotomous variable provided by the data. Multivariable Logistic regression was used to analyze the association between TSH levels and prognosis after adjusting for confounding factors. A sensitivity analysis was conducted which categorized the study population as three groups (i.e., decreased, normal, and elevated TSH levels) using the range of 0.30-3.00 mU/L as the normal range of TSH. RESULTS: A total of 3 425 ICU patients were enrolled in the study, of which 2 692 (78.60%) were with normal TSH and 733 (21.40%) were with abnormal TSH. There was no statistically significant difference in gender, age, ethnicity, type of admission and the ratio of MV between the normal TSH and abnormal TSH groups. Compared with normal TSH group, the patients in abnormal TSH had a higher SOFA, SAPS II and SID30 scores as well as the ratio of RRT [SOFA score: 4 (2, 7) vs. 4 (2, 6), SAPS II score: 38.02±13.76 vs. 36.53±13.75, SID30 score: 11 (4, 22) vs. 11 (0, 20), RRT ratio: 5.32% (39/733) vs. 3.49% (94/2 692), all P < 0.05]. The hospital mortality of patients in normal TSH was significantly higher than that of those in abnormal TSH [9.82% (72/733) vs. 5.94% (160/2 692), P < 0.01]. After adjusting for confounding factors, abnormal TSH was significantly associated with hospital mortality [odds ratio (OR) = 1.71, 95% confidence interval (95%CI) was 1.24-2.35, P = 0.001]. In the sensitivity analysis in which the range of 0.30-3.00 mU/L was used as the normal range of TSH, compared with normal TSH, decreased TSH (OR = 2.36, 95%CI was 1.40-3.97, P = 0.001) and elevated TSH (OR = 1.44, 95%CI was 1.05-1.98, P = 0.023) were both significantly associated with increased hospital mortality. CONCLUSIONS: An abnormal level of TSH within 24 hours after admitted to ICU is an independent risk factor for hospital mortality among ICU patients.

Early exposure to environmental levels of sulfamethoxazole triggers immune and inflammatory response of healthy zebrafish larvae.

Trace levels of antibiotics are increasingly being detected in aquatic environment and their potential toxicity to aquatic organisms is concerning. Sulfamethoxazole (SMX), a veterinary sulfonamide widely used across the globe, exists ubiquitously in aquatic environment with concentrations up to micrograms per liter. This study aims to investigate the effects of environmentally relevant levels (0.1, 1, 10, 100 µg/L) of SMX on the health of zebrafish during early development. Our results show that SMX delays the hatchment of embryos and reduces the body length. A dose-response relationship of oxidative stress indicators including total-antioxidant capacity (T-AOC), inducible nitric oxide synthase (iNOS) and total nitric oxide synthase (TNOS), catalase (CAT) has been observed. Additionally, SMX up-regulates the gene expression of several key proinflammatory cytokines and their corresponding proteins including interleukin-1ß (IL-1ß), interferon-γ (IFN-γ) and interleukin-11 (IL-11) and the expression of genes including interleukin-6 (il-6), tumor necrosis factor-α (tnf-α). This indicates that early exposure of SMX may evoke inflammation response in healthy fish. Inhibition of lysozyme and recombination-activating genes (rags) suggests that SMX suppresses the ability of zebrafish to resist pathogen. The reduction of the expression of Toll-like receptors (TLRs) related genes and significant correlations between TLRs and other immune-related genes reveal that TLRs might be an immunoregulator of SMX for zebrafish embryos and larvae. The novelty of this study lies in that early exposure to environmental levels of SMX not only affects the growth and development of zebrafish larvae, but also triggers oxidative stress and inflammation, resulting in a reduction in host immune defense via TLRs in healthy fish.

Analyte migration electrospray ionization for rapid analysis of complex samples with small volume using mass spectrometry.

Complex biological matrices can be effectively removed in the analyte migration process because of their weak solubility in organic solvents. This technique offers other potential advantages, including high-sensitivity and the capability of performing a direct analysis of the components and their metabolites in small-volume raw samples without any pretreatment.