It was found that carbon atomic emission can be excited in low temperature dielectric barrier discharge (DBD), and an atmospheric pressure, low power consumption, and compact microplasma carbon atomic emission spectrometer (AES) was constructed and used as a universal and sensitive gas chromatographic (GC) detector for detection of volatile carbon-containing compounds. A concentric DBD device was housed in a heating box to increase the plasma operation temperature to 300 °C to intensify carbon atomic emission at 193.0 nm. Carbon-containing compounds directly injected or eluted from GC can be decomposed, atomized, and excited in this heated DBD for carbon atomic emission. The performance of this new optical detector was first evaluated by determination of a series of volatile carbon-containing compounds including formaldehyde, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, and absolute limits of detection (LODs) were found at a range of 0.12-0.28 ng under the optimized conditions. Preliminary experimental results showed that it provided slightly higher LODs than those obtained by GC with a flame ionization detector (FID). Furthermore, it is a new universal GC detector for volatile carbon-containing compounds that even includes those compounds which are difficult to detect by FID, such as HCHO, CO, and CO2. Meanwhile, hydrogen gas used in conventional techniques was eliminated; and molecular optical emission detection can also be performed with this GC detector for multichannel analysis to improve resolution of overlapped chromatographic peaks of complex mixtures.
Escin has been used extensively to treat chronic venous insufficiency, hemorrhoids, and edema resulting from cerebral ischemic damage, trauma or operation. However, no studies have looked at the anti-inflammatory properties of escin administered by intravenous injection, and it is still not clear whether escin has an effect on the immune system. This study seeks to investigate the time-dependent anti-inflammatory properties of escin and its effect on the immune system. The anti-inflammatory effect of escin was observed in carrageenan-induced paw edema and acetic acid-induced capillary permeability in mice. The immunopharmacological effects of escin were evaluated by spleen index (SI), thymus index (TI), proliferative capacity of splenocytes (PS), lymphocyte count (LC), serum TNF-alpha levels, and phagocytic rate (PR) in mice. Escin treatment showed a significant anti-inflammatory effect, similar to that seen with dexamethasone treatment. However, the duration of the anti-inflammatory response was longer with escin treatment than with dexamethasone treatment. The results also demonstrated that escin had no significant effects on SI, TI, LC, PS, TNF-alpha levels, and PR. The findings suggest that escin is a potent anti-inflammatory drug with long-lasting anti-inflammatory effects and without any immunosuppressive effects.
A simple, rapid, and portable system consisted of a laboratory-built miniaturized dielectric barrier discharge atomic emission spectrometer and a microwave-assisted persulfate oxidation reactor was developed for sensitive flow injection analysis or continuous monitoring of total organic carbon (TOC) in environmental water samples. The standard/sample solution together with persulfate was pumped to the reactor to convert organic compounds to CO2, which was separated from liquid phase and transported to the spectrometer for detection of the elemental specific carbon atomic emission at 193.0 nm. The experimental parameters were systematically investigated. A limit of detection of 0.01 mg L(-1) (as C) was obtained based on a 10 mL sample injection volume, and the precision was better than 6.5% (relative standard deviation, RSD) at 0.1 mg L(-1). The system was successfully applied for TOC analysis of real environmental water samples. The obtained TOC value of 30 test samples agreed well with those by the standard high-temperature combustion coupled nondispersive infrared absorption method. Most importantly, the system showed good capability of in situ continuous monitoring of total organic carbon in environmental water.
The solubility and digestion efficiency are two crucial factors that might affect the identification of integral membrane proteins (IMPs). In this work, 1% (v/v) ionic liquid (IL), 1-butyl-3-methyl imidazolium tetrafluoroborate (BMIM BF 4 ), added in NH 4 HCO 3 buffer (pH 8.3), was applied as a sample preparation buffer for IMPs analysis. Compared to the commonly used sodium dodecyl sulfate and methanol methods, the number of identified IMPs from rat brain by microcolumn reversed phase liquid chromatography (μRPLC)-electrospray ionization tandem mass spectrometry (ESI-MS/MS) was improved by over three times, which might be due to the fact that BMIM BF 4 offered high solubilizing ability for IMPs and good compatibility for tryptic digestion. Furthermore, compared to Rapigest and urea methods, with BMIM BF 4 method, the number of identified IMPs from rat brain could be improved 25% and 80%, respectively, which might be contributed to the good solubilizing ability and high thermal stability of such IL. With the sample treated by BMIM BF 4 method, by 2D-nanoSCX-RPLC-ESI-MS/MS, 1,450 non-redundant proteins and 7,978 unique peptides were identified from rat brain, and 418 proteins contained at least one predicted transmembrane domain, with false discovery rates of less than 1% for peptide identification, and at least two identified unique peptides per protein. All these results demonstrate that the BMIM BF 4 method is of high potential for the large-scale identification of IMPs.
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