Chlorinated paraffins in takeout food and its packaging in Beijing, China and dietary exposure risk.

Chlorinated paraffins (CPs) are hazardous to humans, and dietary intake acts as the primary pathway for human exposure to CPs. Takeout food is popular worldwide, but the presence of CPs in takeout food and its packaging is unclear. In this study, the concentrations and distributions of short- and median-chain CPs (SCCPs and MCCPs, respectively) were measured in 97 samples of four categories of takeout food and 33 samples of three types of takeout packaging. The SCCP and MCCP median concentrations for the takeout food samples were 248 and 339, 77.2 and 98.2, 118 and 258, 42.9 and 64.4 ng/g wet weight in meat, starch, half meat/half starch, and vegetables, respectively. Takeout food contained higher concentrations of SCCPs than MCCPs. The dominant SCCP and MCCP congener groups in takeout food were C10Cl6-7 and C14Cl7-8, respectively. The CP concentrations in takeout food were lower than those in packaging. The SCCP and MCCP median concentrations, respectively, in packaging were 9750 and 245 ng/g in polypropylene, 2830 and 135 ng/g in paper, and 2060 and 119 ng/g in aluminum foil. The concentrations of SCCPs and MCCPs were comparable in aluminum foil, whereas the concentrations of SCCPs were higher than those of MCCPs in polypropylene and paper. Correlations between CP concentrations in the takeout food and packaging indicated that CPs in packaging were potentially an important source of CPs in the takeout food. A dietary exposure risk assessment showed the takeout food posed a low risk for human exposure to CPs; however, high-frequency consumption may pose a health risk. This study clarified the current contamination situation in takeout food in Beijing, China. The resulting data could be used to prevent human exposure to CPs through dietary intake and to facilitate the market's control over the quality of takeout food.

Dual-mode detection of fluorine-containing pesticides (bifenthrin, flufenoxuron, diflubenzuron) via ratiometric fluorescence and the Tyndall Effect of fluorescent organic nanoparticles.

The Tyndall Effect assay (TEA) has been applied into colorimetric metal ion detection since 2019. However, the TEA-based sensor for pesticide detection has never been reported till now. Herein, a facile fluorescent organic nanoparticle (FON)-based sensor is firstly developed for fluorine-containing pesticide detection through ratiometric fluorescence assay (FLA) and TEA. For FLA, the intensity of the second-order Tyndall scattering peak (STS590nm) and the fluorescence peak of the FON-based sensor would increase and remain unchanged respectively when adding bifenthrin, flufenoxuron, and diflubenzuron. The detection limits were respectively 9.34, 6.91, and 3.60 µg/kg. For TEA, the increased STS590nm intensity displayed a bright and visible light beam. An economical, simple, and portable device was then constructed to visually monitor the analytes. The sensor was successfully used to detect the analytes in teas through FLA and TEA with the recoveries and RSD ranging from 86.27-100.00 %, and 0.00-5.68 %, respectively.

Phenylboronic acid-functionalized cross-linked chitosan magnetic adsorbents for the magnetic solid-phase extraction of benzoylurea pesticides.

In this study, a 4-formylphenylboronic acid-modified cross-linked chitosan magnetic nanoparticle (FPBA@CCHS@Fe3 O4 ) was fabricated. The synthesized material was utilized as the magnetic solid-phase extraction adsorbent for the enrichment of six benzoylurea pesticides. In addition to B-N coordination, FPBA@CCHS@Fe3 O4 interacts with benzoylureas through hydrogen bonds and π-π stacking interaction on account of rich active groups (amino and hydroxyl) and aromatic rings in structure. Compared to traditional extraction methods, less adsorbent (20 mg) and reduced extraction time (3 min) were achieved. The adsorbent also exhibited good reusability (no less than 10 times). Coupled with a high-performance liquid chromatography-diode array detector, satisfactory recoveries (89.1-103.9%) and an acceptable limit of detection (0.2-0.7 µg/L) were obtained. Under optimized conditions, the established method was successfully applied to the tea infusion samples from six major tea categories with acceptable recoveries ranging from 76.8 to 110%, indicating its application potential for the quantitative detection of pesticides in complex matrices.

Tissue-Protective Effect of Erdosteine on Multiple-Organ Injuries Induced by Fine Particulate Matter.

BACKGROUND Fine particulate matter (PM2.5) is the air pollutant that most threatens global public health. The purpose of this study was to observe the inflammatory and oxidative stress injury of multiple organs induced by PM2.5 in rats and to explore the tissue-protective effect of erdosteine. MATERIAL AND METHODS We randomly divided 40 male Wistar rats into a blank control group, a saline group, a PM2.5 exposure group, and an erdosteine intervention group. We assessed changes in organs tissue homogenate and biomarkers of inflammation and oxidative stress in serum and bronchoalveolar lavage fluid (BALF). RESULTS (1) The expressions of IL-6, IL-1ß, TNF-alpha, 8-OHdG, 4-HNE, and PCC in serum and BALF of the PM2.5 exposure group increased, but decreased after treatment with erdosteine, suggesting that erdosteine treatment attenuates inflammatory and oxidative stress injury. (2) The expression of γ-GCS in serum and lungs in the PM2.5 exposure group increased, but did not change significantly after treatment with erdosteine. This suggests that PM2.5 upregulates the level of γ-GCS, while erdosteine does not affect this protective response. (3) The expression of T-AOC in serum, lungs, spleens, and kidneys of the PM2.5 exposure group decreased, but increased after treatment with erdosteine. Our results suggest that PM2.5 can cause imbalance of oxidation/anti-oxidation in multiple organs, and erdosteine can alleviate this imbalance. CONCLUSIONS PM2.5 exposure can lead to inflammatory and oxidative stress damage in serum and organ tissues of rats. Erdosteine may be an effective anti-inflammatory and antioxidant that can reduce this injury.

Perfluoro octanoic acid-modified magnetic hyperbranched polyamideamine as a sorbent for the extraction of fluorine-containing pesticides from water samples.

Perfluoro octanoic acid was modified on the surface of magnetic hyperbranched polyamideamine by acid amine condensation. The morphology and chemical composition of perfluoro octanoic acid-modified magnetic hyperbranched polyamideamine was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, zeta potential, particle size analysis, Brunauer-Emmett-Teller measurement, and X-ray photoelectron spectroscopy. Perfluoro octanoic acid-modified magnetic hyperbranched polyamideamine was applied in magnetic solid phase extraction for the separation and enrichment of four fluorine-containing pesticides (indoxacarb, metaflumizone, cyflumetofen, and cyhalothrin). The magnetic solid phase extraction method based on perfluoro octanoic acid-modified magnetic hyperbranched polyamideamine has low method detection limits (0.30-0.49 µg/L), a satisfactory coefficient of determination (0.9995-0.9999), wide linear ranges (2.5-250 µg/L), and good repeatability (intraday: 2.6-4.7%; interday: 1.1-7.9%). The enrichment factors and extraction efficiences varied from 55 to 76 and 69 to 96%, respectively. The sorbent-to-sorbent reproducibility was in the range of 3.2-7.6%, indicating that the synthesis of the sorbent was reliable. For the detection of actual water samples, the relative recoveries were in the range from 80.1 to 114.4% with relative standard deviations less than 9.6%. The calculation results of quantum chemistry calculations showed that after the modification of perfluoro octanoic acid, the interaction between the sorbent and four fluorine-containing pesticides was stronger.

Phosphonium-based deep eutectic solvent coupled with vortex-assisted liquid-liquid microextraction for the determination of benzoylurea insecticides in olive oil.

In this study, a novel method using a phosphonium-based deep eutectic solvent coupled with vortex-assisted liquid-liquid microextraction was investigated for the enrichment and separation of five benzoylurea insecticides in olive oil. The experimental factors affecting the extraction efficiency, including the extractant type, deep eutectic solvent volume, extraction time, and extraction mode, were optimized. Under optimal conditions, good linearity was observed for all target analytes, with correlation coefficients (r) ranging from 0.9971 to 0.9998; the limits of detection were in the range of 1.5 to 7.5 µg/L, and the recoveries of analytes using the proposed method ranged between 66.9 and 111.0%. The simple, rapid, and effective method was successfully applied for detecting target analytes in olive oil sample.

A fixed nitrous oxide/oxygen mixture as an analgesic for patients with postherpetic neuralgia: study protocol for a randomized controlled trial.

BACKGROUND: The pain management of postherpetic neuralgia (PHN) remains a major challenge, with no immediate relief. Nitrous oxide/oxygen mixture has the advantages of quick analgesic effect and well-tolerated. The purpose of this study is to investigate the analgesic effect and safety of nitrous oxide/oxygen mixture in patients with PHN. METHODS/DESIGN: This study is a single-center, two-group (1:1), randomized, placebo-controlled, double-blind clinical trial. A total of 42 patients with postherpetic neuralgia will be recruited and randomly divided into the intervention group and the control group. The control group will receive routine treatment plus oxygen, and the intervention group will receive routine treatment plus nitrous oxide/oxygen mixture. Data collectors, patients, and clinicians are all blind to the therapy. The outcomes of each group will be monitored at baseline (T0), 5 min (T1), and 15 min (T2) after the start of the therapy and at 5 min after the end of the therapy (T3). The primary outcome measure will be the pain intensity. Secondary outcomes included physiological parameters, adverse effects, patients' acceptance of analgesia, and satisfaction from patients. DISCUSSION: Previous studies have shown that nitrous oxide/oxygen mixture can effectively relieve cancer patients with breakthrough pain. This study will explore the analgesic effect of oxide/oxygen mixture on PHN. If beneficial to patients with PHN, it will contribute to the pain management of PHN. TRIAL REGISTRATION: Chinese Clinical Trial Register ChiCTR1900023730 . Registered on 9 June 2019.

Exploration and analysis of the value of tumor-marker joint detection in the pathological type of lung cancer.

Lung cancer is a disease characterized by the uncontrolled growth of cells in lung tissue. If left untreated, cell growth can spread beyond the lungs to a process called metastasis and reach surrounding tissues or other organs. This experiment was set up to discuss and analyze the research value of joint detection of tumor markers including carcino-embryonic antigen (CEA), cytokeratin 19 fragments (CYFRA21-1) and neuron-specific enolase (NSE) in the diagnosis and pathological type of lung cancer. From November 2016 to February 2018, 378 cases of patients with lung cancer treated in our hospital and 200 cases of people with healthy physical examinations were collected. The electrochemical immunoluminescence method was adopted to detect the CEA, CYFRA21-1 and NSE. The detected positive rate and the concentration of CEA, CYFRA21-1 and NSE of lung cancer group were higher than that of the healthy physical examination group. The differences were of statistical significance (P<0.05); the detected positive rate of CEA and CYFRA21-1 and the concentration of CEA, CYFRA21-1 and NSE of squamous carcinoma group were higher than that of the adenocarcinoma group. The differences were of statistical significance (P<0.05). The CEA, CYFRA21-1 and NSE are related to the pathological type of lung cancer and can be regarded as related indicators to diagnose lung cancer.

Preparation of magnetic attapulgite/polypyrrole nanocomposites for magnetic effervescence-assisted dispersive solid-phase extraction of pyrethroids from honey samples.

In this work, a novel extraction technique based on the effervescence-assisted dispersion and magnetic recovery of attapulgite/polypyrrole sorbents was developed for determining the concentrations of five pyrethroids in honey samples. The magnetic nanoparticles were synthesized by a one-pot method. Several experimental parameters that affected the extraction efficiency, including the dispersion conditions, pH, ionic strength, and desorption conditions, were investigated. Under optimal conditions, the calibration curves for the five pyrethroids in honey samples exhibited good linearity, with r2 values ranging from 0.9979 to 0.9990. The limits of detection varied between 0.21 and 0.34 µg/L. Satisfactory recoveries of 81.42-106.73% with intra- and interday relative standard deviations of less than 6.94 and 10.89%, respectively, were obtained. Moreover, the sorbents exhibited acceptable batch-to-batch repeatability in the range of 5.06-15.01%, and each sorbent could be reused for up to four extraction cycles without a significant loss in the extraction recovery.

PEG-modified magnetic Schiff base network-1 materials for the magnetic solid phase extraction of benzoylurea pesticides from environmental water samples.

It is necessary to establish a rapid, simple and environmentally friendly detection method for benzoylurea pesticides (BUs) in environmental water samples because of their toxicity in environmental circulation. Herein, a novel polyethylene glycol (PEG) modified magnetic covalent organic framework material based on the Schiff base reaction was prepared (PEG/Fe3O4@SNW-1). This material was used as a sorbent for enriching five BUs by magnetic solid phase extraction prior to detection via high-performance liquid chromatography. After the optimization of several parameters (such as the salinity, extraction time, amount of sorbent, desorption time, etc.) that influenced the recovery of the magnetic solid phase extraction process, the limits of detection (S/N = 3) were defined as less than 1.0 µg L-1, and the limits of quantitation (S/N = 10) were calculated as being lower than 3.4 µg L-1. A satisfactory linear range of 5-1000 µg L-1 was achieved. Finally, the proposed method was applied to analyze benzoylurea pesticides in three environmental water samples. These results indicated that the proposed method was feasible and demonstrated the potential application of the PEG/Fe3O4@SNW-1 material for detecting similar pesticide residues in environmental water samples.

Extraction of benzoylurea pesticides from tea and fruit juices using deep eutectic solvents.

In this study, low-density deep eutectic solvent combined with dispersive liquid-liquid microextraction was applied to the extraction of five benzoylurea insecticides (BUs, including diflubenzuron, triflumuron, hexaflumuron, flufenoxuron, and chlorfluazuron) from beverages. Then the extracted and concentrated samples were analyzed and detected using the high-performance liquid chromatography combined with an ultraviolet detector. The DESs were synthesized by [P14,6,6,6]Cl as hydrogen bond acceptor and tetradecyl alcohol as hydrogen bond donor, and then characterized by Fourier transform infrared spectroscopy. In the experiment, the key factors affecting the extraction efficiency were screened by Plackett-Burman design and optimized with the central composite design. The extraction recovery rates were 85.91-95.12%. The limits of detection and correlation coefficients of the method were 0.30-0.60 µg L-1 and 0.9992-0.9997. Finally, the method was applied to determine the BUs in four beverage samples, and satisfactory recoveries, within the range of 76.87-101.19% were achieved. The present method has the potential to be applied to the detection of BUs in aqueous samples.

MiR-34c-5p plays a protective role in chronic obstructive pulmonary disease via targeting CCL22.

Objective: To study the role of miR-34c-5p targeting CCL22 in affecting the progression of chronic obstructive pulmonary disease (COPD). Methods: The dual-luciferase reporter gene assay was applied to verify the targeting relationship of miR-34c-5p and CCL22. The rats were randomly assigned into Control, COPD, COPD + empty plasmids, COPD + agomir, COPD + CCL22 shRNA and COPD + agomir + CCL22 groups. COPD model was built by using cigarette smoke exposure and LPS instillation. After 28 days, the pulmonary function was examined. ELISA method was used to detect TNF-α and IL-8 levels in bronchoalveolar lavage fluid (BALF), HE staining and Masson staining to observe the pathomorphological changes of lung tissues, qRT-PCR and/or Western blot to determine miR-34c-5p and CCL22 levels, and immunohistochemical staining to measure the expression of MMP-9 and TIMP-1. Results: MiR-34c-5p could target CCL22 to down-regulate its expression. Both miR-34c-5p agomir and CCL22 shRNA could reduce breathing frequency (f), airway resistance (RI), and the levels of IL-8 and TNF-α in BALF of COPD rats with increased Cydn (dynamic lung compliance) and PIF (peak inspiratory flow). Besides, the inflammatory cell infiltration, rupture of partial alveolus, enlarged alveolar cavity, and increased deposition of collagen fibers were observed in COPD rat tissues, with rise in mean linear intercept (MLI) and reduction in mean alveolar number (MAN), which could be reversed by miR-34c-5p agomir or CCL22 shRNA. Conclusion: MiR-34c-5p may promote inflammation response and maintain the protease-antiprotease balance via targeting CCL22, which provides scientific basis for the clinical treatment of COPD.

A Fixed Nitrous Oxide and Oxygen Mixture for Analgesia in Children With Leukemia With Lumbar Puncture-induced Pain: A Randomized, Double-blind Controlled Trial.

CONTEXT: Leukemia is the most common cancer in the childhood population. Lumbar puncture (LP) plays central role in the diagnosis and treatment process, but options for analgesia are limited. OBJECTIVES: The present study aims to evaluate the efficacy of a fixed N2O/O2 mixture to reduce pain in children with leukemia during LP as compared with placebo. METHODS: A double-blind, placebo-controlled, and randomized clinical trial involving children who needed LP for diagnosis or treatment was conducted in the pediatrics department of the General Hospital of Ningxia Medical University. Eligible patients were randomly assigned to inhale either a fixed N2O/O2 mixture or O2. The primary endpoint was the maximal pain level felt by the patient during the procedure measured using a numerical rating scale (0-10). RESULTS: One-hundred fourteen consecutive patients were enrolled in this study and randomized. Pain scores during the procedure showed a significant decrease in N2O/O2 mixture-treated patients to 1.05 ± 1.40 versus 8.00 ± 2.13 in controls (P < 0.01). No serious adverse effects were attributed to N2O/O2 mixture inhalation. Analysis of the satisfaction of patients receiving N2O/O2 mixture indicated that medical staff were satisfied with this treatment. CONCLUSIONS: This study demonstrated that self-administered fixed N2O/O2 is efficient to reduce pain related to LP in children with leukemia.

Magnetic mixed hemimicelles dispersive solid-phase extraction based on ionic liquid-coated attapulgite/polyaniline-polypyrrole/Fe3O4 nanocomposites for determination of acaricides in fruit juice prior to high-performance liquid chromatography-diode array detection.

In this research, a novel method using magnetic mixed hemimicelles dispersive solid-phase extraction (MMHDSPE) based on C16mimBr-coated attapulgite/polyaniline-polypyrrole/Fe3O4 (ATP/PANI-PPY/Fe3O4) nanocomposites were investigated for enrichment and separation of three acaricides in fruit juice. In this method, we combined the simplicity and speed of dispersive solid-phase extraction, the advantages of mixed hemimicelles and the facility of the phase separation of the magnetic nanoparticles to develop a simple, rapid, sensitive, and effective method for detecting target analytes from the juice samples. ATP/PANI-PPY/Fe3O4 nanocomposites were successfully synthesized using a one-pot method. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental factors affecting the extraction efficiency including the sorbent type, amount of ATP/PANI-PPY/Fe3O4 nanocomposites, volume of ILs, sonication time, pH, and desorption conditions were optimized. Under the optimal conditions, good linearity was observed for all target analytes, with correlation coefficients (r2) ranging from 0.9994 to 0.9999; the limits of detection (LOD) were in the range of 0.16-0.57µgL-1, and the recoveries of analytes using the proposed method ranged between 88.67% and 95.10%. The sorbents exhibited excellent repeatability in the range of 1.83-4.24% in extracting the three target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.19-6.24% and 2.23-8.36%, respectively. The method was successfully applied to analyze fruit juice samples by rapid preconcentration of acaricides.

Effect of miR-23a on anoxia-induced phenotypic transformation of smooth muscle cells of rat pulmonary arteries and regulatory mechanism.

We investigated the possible implication of miR-23a in anoxia-induced phenotypic transformation of the pulmonary arterial smooth muscle and studied the mechanism of upregulation of miR-23a expression in anoxia. The collagenase digestion method was used for preparing rat primary pulmonary artery smooth muscle cell (PASMC) culture. SM-MHC, SM-α-actin, calponin-1 and SM22α protein expression levels were evaluated using western blot analysis after the ASMCs were subjected to anoxia treatment (3% O2). Transfection with miR-23a mimics were conducted when PASMCs were under normoxia and anoxia conditions. EdU staining was used to detect the proliferative activity of PASMCs. Cells were transfected with HIF-1α specific siRNA under anoxia condition. RT-qPCR was used to detect miR-23a expression in PASMCs. Chromatin immunoprecipitation method was employed to verify the binding sites of HIF-1α. The dual-luciferase reporter gene was used to study the role of HIF-1 and its binding sites. Rat hypoxic pulmonary hypertension models were established to study the expression of miR-23a using RT-qPCR method and to verify the expression of miR-23a in the arteriole of the rat pulmonary. Our results showed that compared with normoxia condition, under anoxia condition (3% O2), the expression levels of the contractile phenotype marker proteins decreased significantly after 24 and 48 h. The positive rate of the EdU staining increased significantly and the expression of miR-23a increased. Transfection with miR-23a-mimic downregulated the expression of contractile marker proteins and improved the positive rate of the EdU staining under normoxia. Anoxia and transfection with HIF-1α enhanced the activity of the wild-type Luc-miR-23a-1 (WT) reporter gene. We concluded that miR-23a participated in the anoxia-induced phenotypic transformation of PASMCs. Increased expression of miR-23a under anoxia may primarily be due to miR-23a-1 and miR-23a-3 upregulation. The anoxia-induced upregulation of miR-23a was regulated by HIF-1.

miR-200c regulates crizotinib-resistant ALK-positive lung cancer cells by reversing epithelial-mesenchymal transition via targeting ZEB1.

Crizotinib is an orally administered drug for the treatment of patients with anaplastic lymphoma kinase (ALK)-positive locally advanced or metastatic non­small cell lung cancer (NSCLC). Despite the impressive efficacy of crizotinib in the treatment of ALK­positive lung cancer, acquired resistance eventually develops in the majority of patients. The microRNA (miR)­200c reverses the resistance of lung cancer cells to various chemotherapeutic drugs and molecular targeted drugs, however, whether it can reverse the resistance of crizotinib remains unknown. The present study established a crizotinib resistant cell line (NCI­2228/CRI), which was derived from the parental NCI­2228 cell line by long­term exposure to increasing concentrations of crizotinib. Through overexpression and suppression of miR­200c expression, the characteristics associated with epithelial­mesenchymal transition (EMT), including morphology, EMT marker proteins and cellular mobility, were investigated. Cell viability and invasion assays demonstrated that high expression of miR­200c significantly inhibited the proliferation, migration and invasion of NCI­2228 cells compared with the negative control. A luciferase reporter assay indicated that miR­200c directly targeted the 3'­untranslated region of zinc finger E­box binding homeobox 1. Additionally, reverse transcription­quantitative polymerase chain reaction analysis demonstrated that the mRNA levels of N­cadherin and Vimentin were decreased in NCI­2228 cells transfected with miR­200c mimic compared with negative control cells, whereas the mRNA level of E­cadherin was increased. In addition, EMT was reversed by miR­200c, which suggests that miR­200c may serve a role in mediating the sensitivity of NCI­2228/CRI cells to crizotinib. The present study may therefore contribute to improving the sensitivity of ALK positive lung cancer cells to crizotinib.

Extensible automated dispersive liquid-liquid microextraction.

In this study, a convenient and extensible automated ionic liquid-based in situ dispersive liquid-liquid microextraction (automated IL-based in situ DLLME) was developed. 1-Octyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]imide ([C8MIM]NTf2) is formed through the reaction between [C8MIM]Cl and lithium bis[(trifluoromethane)sulfonyl]imide (LiNTf2) to extract the analytes. Using a fully automatic SPE workstation, special SPE columns packed with nonwoven polypropylene (NWPP) fiber, and a modified operation program, the procedures of the IL-based in situ DLLME, including the collection of a water sample, injection of an ion exchange solvent, phase separation of the emulsified solution, elution of the retained extraction phase, and collection of the eluent into vials, can be performed automatically. The developed approach, coupled with high-performance liquid chromatography-diode array detection (HPLC-DAD), was successfully applied to the detection and concentration determination of benzoylurea (BU) insecticides in water samples. Parameters affecting the extraction performance were investigated and optimized. Under the optimized conditions, the proposed method achieved extraction recoveries of 80% to 89% for water samples. The limits of detection (LODs) of the method were in the range of 0.16-0.45 ng mL(-1). The intra-column and inter-column relative standard deviations (RSDs) were <8.6%. Good linearity (r>0.9986) was obtained over the calibration range from 2 to 500 ng mL(-1). The proposed method opens a new avenue for automated DLLME that not only greatly expands the range of viable extractants, especially functional ILs but also enhances its application for various detection methods. Furthermore, multiple samples can be processed simultaneously, which accelerates the sample preparation and allows the examination of a large number of samples.

Lathyrol diterpenes as modulators of P-glycoprotein dependent multidrug resistance: structure-activity relationship studies on Euphorbia factor L3 derivatives.

Five series of 37 new acylate and epoxide derivatives (3-39) of Euphorbia factor L3, a lathyrol diterpene isolated from Euphorbia lathyris, were designed by modifying the hydroxyl moiety of C-3, C-5, or C-15. Chemoreversal effects of the acylates on multidrug resistance (MDR) were evaluated in breast cancer multidrug-resistant MCF-7/ADR cells that overexpress P-glycoprotein (P-gp). Eight derivatives exhibited greater chemoreversal ability than verapamil (VRP) against adriamycin (ADR) resistance. Compounds 19 and 25 exhibited 4.8 and 4.0 times, respectively, more effective reversal ability than VRP against ADR resistance. To determine the key characteristics of Euphorbia factor L3 derivatives that contribute to MDR reversal, we conducted a structure-activity relationship study of these compounds. The simulation studies indicated different possible mechanisms and revealed the important influence of hydrophobic interactions and hydrogen bonds in the flexible cavity of P-gp.

Nonwoven polypropylene as a novel extractant phase holder for the determination of insecticides in environmental water samples.

In this work, a novel liquid-phase microextraction approach using nonwoven polypropylene as the extraction solvent holder was developed. Nonwoven polypropylene, a hydrophobic material, is widely used in the cleanup of oil spills. Due to its large surface area, efficient, and full extraction can be achieved. Nonwoven polypropylene containing an ionic liquid was used to extract benzoylurea insecticides (diflubenzuron, teflubenzuron, flufenoxuron, and chlorfluazuron) through vortex-assisted liquid-liquid microextraction. The parameters that affected the extraction efficiency included the type and volume of the extractant, the extraction time, the time and solvent volume for desorption and the mass and surface area of the nonwoven polypropylene. Under the optimized conditions, good linearity was obtained, with coefficients of determination greater than 0.9996, and the limit of detections of these compounds, calculated at S/N = 3, were in the range of 0.73-5.0 ng/mL. The recoveries of the four insecticides at two spiked levels ranged from 93.3 to 102.0%, with relative standard deviations of less than 4.0%. The proposed method was then successfully used for the rapid determination of benzoylurea insecticides in spiked real water samples before liquid chromatographic analysis. The procedure is simple, inexpensive, easy to execute, and can be widely used.

Borohydride ionic liquids and borane/ionic-liquid solutions as hypergolic fuels with superior low ignition-delay times.

In propellant systems, fuels of choice continue to be hydrazine and its derivatives, even though they comprise a class of acutely carcinogenic and toxic substances which exhibit rather high vapor pressures and require expensive handling procedures and costly safety precautions. Hypergolic ionic liquids tend to have low volatility and high thermal and chemical stability, and often exhibit wide liquid ranges, which could allow the use of these substances as bipropellant fuels under a variety of conditions. A new family of borohydride ionic liquids and borane-ionic-liquid solutions is described which meets nearly all of the desired important criteria for well-performing fuels. They exhibit ignition-delay times that are superior to that of any known hypergolic ionic liquid and may thus be legitimate replacements for hydrazine and its derivatives.