Succinylation is a highly conserved post-translational modification that is processed
enzymatic and non-enzymatic mechanisms. Succinylation exhibits strong effects on protein stability, enzyme ...activity, and transcriptional regulation. Protein succinylation is extensively present in the liver, and increasing evidence has demonstrated that succinylation is closely related to hepatic metabolism. For instance, histone acetyltransferase 1 promotes liver glycolysis, and the sirtuin 5-induced desuccinylation is involved in the regulation of the hepatic urea cycle and lipid metabolism. Therefore, the effects of succinylation on hepatic glucose, amino acid, and lipid metabolism under the action of various enzymes will be discussed in this work. In addition, how succinylases regulate the progression of different liver diseases will be reviewed, including the desuccinylation activity of sirtuin 7, which is closely associated with fatty liver disease and hepatitis, and the actions of lysine acetyltransferase 2A and histone acetyltransferase 1 that act as succinyltransferases to regulate the succinylation of target genes that influence the development of hepatocellular carcinoma. In view of the diversity and significance of protein succinylation, targeting the succinylation pathway may serve as an attractive direction for the treatment of liver diseases.
A simple and easy‐to‐use integrated laser‐induced fluorescence detector for microchip electrophoresis was constructed and evaluated. The fluid channels and optical fiber channels in the glass ...microchip were fabricated using standard photolithographic techniques and wet chemical etching. A 473 nm diode‐pumped laser was used as the excitation source, and the collimation and collection optics and mirrors were discarded by using a multimode optical fiber to couple the excitation light straight into the microchannel and placing the microchip directly on the top of the photomultiplier tube. A combination of filter systems was incorporated into a poly(dimethylsiloxane) layer, which was reversibly sealed to the bottom of the microchip to eliminate the scattering excitation light reaching to the photomultiplier tube. Fluorescein/calcein samples were taken as model analytes to evaluate the performance with respect to design factors. The detection limits were 0.05 μM for fluorescein and 0.18 μM for calcein, respectively. The suitability of this simple detector for fluorescence detection was demonstrated by baseline separation of fluorescein isothiocyanate (FITC)‐labeled arginine, phenylalanine, and glycine and FITC within 30 s at separation length of 3.8 cm and electrical field strength of 600 V/cm.
Forest soil is one of the main sources of greenhouse gases CO2, CH4, and N2O. By using static chamber and GS technique, this paper measured in situ the CO2, CH4, and N2O fluxes of Acacia crassicarpa ...plantation in Heshan Hilly Land Interdisciplinary Experimental Station under Chinese Academy of Sciences (CAS), and studied the soil CO2, CH4 and N2O emissions from the plantation under effects of understory removal and Cassia alata addition. The CO2 flux of the plantation maintained at a higher level during rainy season but decreased obviously in dry season, while the CH4 and N2O fluxes varied widely from September to November, with the peaks in October. Under the effects of understory removal and C. alata addition, the soil in the plantation could be a sink or a source of CH4, but consistently a source of CO2 and N2O. Understory removal enhanced the soil CO2 emission (P < 0.05 ), C. alata addition increased the soil CH4 emission (P < 0.05), while both understory removal and C. alata addition increased the soil N
Time‐of‐flight mass spectrometry experiments demonstrated that laser ablation generated and mass selected Au2TiO4− cluster anions can unexpectedly oxidize three CO molecules in an ion trap reactor. ...This is an improvement on the more commonly observed oxidation of at most two CO molecules by a doped cluster. Quantum chemistry calculations were performed to rationalize the reactions. The lowest energy isomer of Au2TiO4− contains a superoxide unit, the participation of which in CO oxidation can be promoted by the Au2 dimer. The Au2 dimer functions as a rather flexible electron reservoir in each CO oxidation step in terms of the release and storage of electrons to drive the dissociation of superoxide to peroxide and then to lattice oxygen atoms, which can be removed by reaction with CO molecules. This gas‐phase study enriches our understanding toward the nature of reactive oxygen species involved in gold‐catalyzed oxidation reactions.
More the merrier: Time‐of‐flight mass spectrometry experiments and quantum chemistry calculations demonstrated that the Au2 dimer in Au2TiO4− clusters functions as a rather flexible electron reservoir to promote the dissociation of superoxide to peroxide and then to lattice oxygen species, which can be removed by reaction with three CO molecules consecutively (see figure).
Automated online SPE‐HPLC‐MS was established for the determination of deca‐bromodiphenyl ether in human serum. The online SPE with large volume injection was utilized to enhance the sensitivity. ...Online SPE with dilution line greatly decreased matrices effect, which enabled serum samples to be injected directly into pre‐column. Washing line was designed for the system to solve the serious residual phenomenon and reduce the risk of sample wastage and contamination. Under the optimized conditions, the linear of the method was in the range 0.1–10 ng/mL with the LOD of 0.026 ng/mL. The recoveries of serum samples spiked with deca‐bromodiphenyl ether at 0.5 ng/mL was in the range from 83.30 to 102.7% with RSD in interday less than 8.67%. The satisfactory results demonstrated that the method of online sample pretreatment and cleanup recycle were reliable for human serum analysis.
A simple sample enrichment technique, electrokinetic migration enrichment in single phase using a designed device, coupled with ion chromatography is presented for the determination of four anions ...(H2PO4−, Cl−, NO3−, and SO42−) in liquefied petroleum gas by liquid adsorption. The electrokinetic migration enrichment is based on the phenomenon of ion electrokinetic migration to the opposite electrode. When the anions migrated to the anode in a smaller volume chamber under the electric field, the concentration was realized. The main parameters affecting enrichment efficiency of applied voltage and enrichment time were investigated. The ion chromatography condition for anions separation was also studied. Under the optimal electrokinetic migration enrichment and ion chromatography conditions, the four anions were detected simultaneously with good linear relationship (r2 = 0.9908–0.9968) and high precisions (less than 5% of the relative standard deviations of peak areas). The limits of detection of anions (S/N of 3) were in the range of 8–600 μg L−1. The enrichment factors of the four anions ranged from 3.1 to 5.8. The established method was successfully applied to the analysis of the trace anions in liquefied petroleum gas by liquid adsorption with satisfactory results. The advantages of this method are simple operation and low cost.
A laboratory simulation experiment was conducted to study the release of sediment phosphorous and nitrogen under the effects of coating the sediment with plastic, clinoptilolite, calcite, quartz ...sand, and calcium nitrate, aimed to provide scientific basis and technical support to control the sediment nutrient release under the background of water environment pollution by different concentrations of nitrogen and phosphorus. The control efficacy of test coating materials for sediment total phosphorous release was in the order of plastic > calcium nitrate > clinoptilolite > calcite > quartz sand, and that for sediment total nitrogen release was in the order of clinoptilolite > plastic > calcite > quartz sand > calcium nitrate. As for the release of sediment NO(3-)-N, the control efficacy of test coating materials was calcium nitrate > quartz sand > clinoptilolite > calcite > plastic coating; whereas for the release of sediment NH(4+)-N, the sequence was calcium nitrate > plastic coating > clinoptilolite > calcit
A wavelength dispersive X-ray fluorescence (WD-XRF) spectrometry combined with calibration curve method was established for simultaneously analyzing low-Z elements (C, N, O) and Al, Si, Fe in ...polyamide. To investigate the origin of plastic material causing deposition and blocking in instrument engines and pipelines, polyamide 6 (PA 6, an engineering plastic) was chosen as the study object on account of its common use in industry. The sample preparation with pressed powder disk has been developed for determination of six elements in PA 6. Pure Cu metal was used as the matrix and PA 6 was regarded as standard sample for C, N, O elements. PA 6 particles were firstly smashed to uniform powder in liquid nitrogen, and then mixed with inorganic standard powders (Fe
2
O
3
, Al
2
O
3
, SiO
2
, and Na
2
SiO
3
). The mixture was ground to obtain homogeneous calibration materials for WD-XRF analysis. The quantitative property of the calibration curve method for each element was reliable. The limits of detection (S/N≤3) of C, N, O, Al, Si and Fe using WD-XRF were 249, 120, 101, 6.2, 3.3, and 1.8 μg/g, respectively. To confirm the accuracy of the proposed WD-XRF calibration curve method, inductively coupled plasma optical emission spectroscopy (ICP-OES) detection for Al, Si, Fe and elemental analyzer (EA) analysis for C, N, O were utilized. A good correlation of the WD-XRF results with the measurements of ICP-OES and EA was observed.
In this work, a reliable and sensitive method for detecting polybrominated diphenyl ethers （PBDEs） has been developed by the combination of liquid-liquid extraction and gas chromatography-mass ...spectrometry. PBDEs were extracted from a large volume of water by liquid-liquid extraction and purified by silica gel chromatography. In order to reduce the deviation, dibromobiphenyl was exploited as the internal standard to minimize differences among the injections. The quantification was performed using an external standard. Good linear correlation coefficients （〉0.991） and a wide linearity range （ 1,0- 500.0 ng/L） indicated the steadiness of the proposed method. Moreover, the satisfactory recovery （〉75%） suggested that successful determination of PBDEs in river water had been achieved. Furthermore, the deduction behavior of PBDEs in river water could be inferred according to the results.
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