Biomedical subjects

Qiquan Wang

Publications and source records attributed to Qiquan Wang.

11 recordsLinked to original sources

PubMed2026

Comprehensive multi-post-translational modifications profiling reveals age-associated remodeling in skeletal muscle.

Sarcopenia, characterized by the progressive loss of skeletal muscle mass and function, is a major hallmark of aging. Post-translational modifications (PTMs) play essential roles in regulating protein activity and cellular homeostasis; however, how multiple PTMs are remodeled during skeletal muscle aging remains incompletely characterized. Here, we performed comprehensive multi-layered proteomic profiling of skeletal muscle from young (3-month-old) and aged (24-month-old) mice, systematically quantifying the global proteome together with five major PTMs: acetylation, phosphorylation, N-glycosylation, O-glycosylation, and ubiquitination. In total, we identified 5 337 proteins and mapped thousands of PTM sites, generating an integrated atlas of age-associated proteomic and PTM remodeling in skeletal muscle. Pathway enrichment analyses revealed distinct modification-specific patterns: acetylation and phosphorylation were predominantly associated with metabolic and mitochondrial-related pathways; N-glycosylation was enriched in immune- and secretory pathway-related processes; O-glycosylation was associated with muscle contraction-related pathways; and ubiquitination was preferentially linked to cytoskeletal organization in muscle cells. Correlation analyses further uncovered diverse association patterns among different PTMs across protein- and modification-level datasets. Phosphorylation and ubiquitination exhibited consistent positive associations, whereas acetylation and ubiquitination showed both inverse and concordant co-variation patterns across subsets of proteins. Phosphorylation and O-glycosylation displayed heterogeneous association patterns across different proteins, and acetylation and phosphorylation demonstrated positive correlations with distinct age-associated directional changes across protein subsets. Together, these results provide a comprehensive, multi-dimensional view of age-associated remodeling of the skeletal muscle proteome and multiple PTM layers, offering a valuable resource for understanding molecular alterations accompanying muscle aging and sarcopenia.

Animals↗

PubMed2006

Reducing 1,3-dichloropropene emissions from soil columns amended with thiourea.

Soil fumigants are becoming an important source of volatile organic compounds (VOCs) in air, especially in some agricultural areas. In this study, we used thiourea to construct a reactive surface barrier (RSB) at the soil surface for reducing 1,3-dichloropropene (1,3-D) volatilization. The agrochemical thiourea could rapidly transform volatile 1,3-D to nonvolatile products via an SN2 nucleophilic substitution reaction. A catalytic mechanism in thiourea-amended soil facilitated the conversion process. A packed soil column system was employed to investigate the emissions and distribution of 1,3-D and optimize the original fumigant emission-reduction strategy. Volatilization of 1,3-D from the soil surface was significantly reduced in columns amended with a thiourea RSB compared with that of bare soil. Volatilization flux and cumulative emissions decreased with increasing thiourea application rate and increasing fumigation depth in packed soil columns. Surface amendment with the RSB did not affect the subsurface distribution of 1,3-D in the soil profile. Combined application of a thiourea RSB and plastic tarps had a synergetic effect in emission control and could eliminate the relatively high fumigant flux that occurs upon tarp disruption. Therefore, this reduced-risk practice was very effective in reducing atmospheric emissions of VOCs from soil treatment with halogenated fumigants.

Allyl Compounds↗

PubMed2006

Degradation kinetics of manure-derived sulfadimethoxine in amended soil.

Spreading of contaminated manure into agricultural lands as fertilizer is one of the major routes through which veterinary antibiotics enter the environment. In this study, the degradation of manure-derived sulfadimethoxine, a widely used veterinary sulfonamide antibiotic, in manure-amended soil was investigated. A kinetic model, called the availability-adjusted first-order model based on the first-order kinetics and an assumption of the availability of target compound during the degradation process, was developed and was found to fit sulfadimethoxine degradation well. The effect of initial sulfadimethoxine concentration showed that the degradation rate constant increased with decreasing initial concentration, indicating that the bioactivity of the degrading microorganisms in manure-amended soil was sensitive to sulfadimethoxine concentration. Sulfadimethoxine degradation was accelerated with increasing manure content in amended soil. Degradation in nonamended soil was significantly slower than in manure-amended soil. This indicated that sulfadimethoxine may become more persistent once it reaches soil after leaching from manure and that storage of manure for a certain period before application is needed to diminish sulfadimethoxine contamination. Sulfadimethoxine degradation was effectively enhanced with increasing moisture of amended soil. No adverse effect was observed with manure storage on the degradation of manure-derived sulfadimethoxine in amended soil.

Kinetics↗

PubMed2006

Reduced adsorption of ametryn in clay, humic acid, and soil by interaction with ferric ion under Fenton treatment conditions.

Previous work in our laboratory indicated a weak interaction between ferric ion and several triazine/triazinone herbicides during a Fenton treatment process, and the intensity of the interaction was calculated. To further support the existence of this weak interaction, the adsorption of ametryn, a triazine herbicide, was investigated in kaolinite clay, humic acid, and soil under pseudo-Fenton conditions. At a low addition rate of ferric ion, the adsorption of ametryn in clay, humic acid, and soil was enhanced due to the decreased pH resulting from the hydrolysis of ferric ion. But the pH effect was totally neutralized and the adsorption of ametryn was significantly reduced by further addition of ferric ion, demonstrating the existence of the weak interaction between ametryn and ferric acid. Further study showed that the adsorption-reduction effect of ferric ion existed not only with ametryn but also with several other triazine/triazinone herbicides. This weak interaction may accelerate the desorption process during the remediation of triazine/triazinone herbicide-contaminated soil using a Fenton/Fenton-like treatment, but it may also impede the degradation of these herbicides.

Adsorption↗

PubMed2004

Metribuzin degradation by membrane anodic Fenton treatment and its interaction with ferric ion.

Metribuzin, a widely used herbicide and a frequently detected pollutant in the environment, was studied as a target compound for membrane anodic Fenton treatment (AFT), a Fenton technology with application potential for on-site treatment of pesticide wastewater. It was found that the degradation kinetics of metribuzin do not obey the AFT model, a previously developed model that fit AFT degradation kinetics of all previously investigated pesticides. The lack of fit for metribuzin data was determined to result from a weak interaction between metribuzin and the ferric ion, resulting in a significant reduction in availability of metribuzin for reaction with hydroxyl radicals during AFT, thus slowing degradation. A revised kinetic model was developed based on the original AFT model with the addition of this interaction. Results demonstrate that the new kinetic model fits metribuzin degradation data quite well at different delivery rates of Fenton reagent and at different temperatures. This weak interaction is also found to exist between ferric ion and several other triazinone/triazine herbicides during membrane AFT. The interaction intensity correlates with the electron-withdrawing/-donating property of substituents on the triazine/triazinone ring. The stronger the electron-donating ability of substituents, the stronger the interaction.

Herbicides↗

PubMed2003

Competitive degradation and detoxification of carbamate insecticides by membrane anodic Fenton treatment.

The competitive degradation of six carbamate insecticides by membrane anodic Fenton treatment (AFT), a new Fenton treatment technology, was carried out in this study. The carbamates studied were dioxacarb, carbaryl, fenobucarb, promecarb, bendiocarb, and carbofuran. The results indicate that AFT can effectively degrade these insecticides in both single component and multicomponent systems. The carbamates compete for hydroxyl radicals, and their kinetics obey the previously developed AFT kinetic model quite well. Hydroxyl radical reaction rate constants were obtained, and they decrease in the following order: dioxacarb approximately carbaryl > fenobucarb > promecarb > bendiocarb > carbofuran. The AFT is shown to have higher treatment efficiency at higher temperature. Degradation products of the carbamates were determined by gas chromatography/mass spectrometry, and it appears that degradation can be initiated by hydroxyl radical attack at different sites in the molecule, depending on the individual structure of the compound. Substituted phenols are the commonly seen degradation products. The AFT treatment can efficiently remove the chemical oxygen demand of the carbamate mixture, significantly increasing the biodegradability. Earthworm studies show that the AFT is also an effective detoxification process.

Animals↗

PubMed2003

Oxidative degradation and detoxification of aqueous carbofuran by membrane anodic Fenton treatment.

Anodic Fenton treatment (AFT), a new Fenton technology for the treatment of pesticide wastewater, has been reported previously. The substitution of an ion exchange membrane for the salt-bridge, an improvement to the practicality of the AFT without sacrificing treatment efficiency, has also been reported. The oxidative degradation by membrane AFT of carbofuran, a heavily used and toxic carbamate insecticide, was investigated in this study. The results show that the degradation kinetics of carbofuran with different initial concentrations obeys the AFT model, and the treatment efficiency increases with increasing initial concentration. Raising the treatment temperature can result in enhanced degradation of carbofuran in solution. The pseudo-activation energy of carbofuran by membrane AFT was estimated to be 7.66 kJ mol(-1). The results also show that AFT treatment can effectively remove COD and dramatically improve the biodegradability of carbofuran in solution. GC/MS analysis found four degradation products, revealing that the carbamate branch and 3-C in the furan ring are the first and second attack targets of hydroxyl radicals. As shown by the toxicity assay, the fatal toxicity of carbofuran to earthworms can be totally removed. The degradation of carbofuran by AFT is also a detoxification process.

Biodegradation, Environmental↗

PubMed2002

Oxidation of carbaryl in aqueous solution by membrane anodic fenton treatment.

Carbaryl, a commonly used insecticide, was used in this study as a probe to investigate a new Fenton treatment technology, ion exchange membrane anodic Fenton treatment (membrane AFT). It was found that the degradation kinetics of carbaryl by membrane AFT obeys a previously published AFT model quite well. The NaCl (electrolyte) concentration in two half-cells was optimized for two kinds of membrane. Effects of the H(2)O(2)/Fe(2+) ratio and the Fenton reagent delivery rate were also investigated. The treatment efficiency for anion membrane AFT is higher than for salt-bridge AFT under the same operating conditions. Decreasing the delivery rate of Fenton reagents and increasing the treatment temperature also increase the treatment efficiency. The activation energy for carbaryl degradation by anion membrane AFT was estimated to be 14.7 kJ x mol(-1). 1-Naphthol, 1,4-naphthoquinone, and (phthalic acid-O-)yl N-methylcarbamate were detected by GC-MS as the degradation products of carbaryl by Fenton treatment. No decrease in carbaryl degradation rate was found during repeated use (100 times) of the anion exchange membrane. High and stable treatment efficiency can be achieved using an anion exchange membrane rather than a salt-bridge in the AFT system. Because of its effectiveness and convenience, the use of an ion exchange membrane as a substitute for the salt-bridge used in the previous AFT system has brought the AFT technology a major step closer to practical application.

Anions↗

PubMed2002

Dechlorination of chloroacetanilide herbicides by thiosulfate salts.

Halogenated organic compounds (XOCs) are among the most widely used synthetic chemicals. Many XOCs are recalcitrant to natural degradation and have become prominent environmental contaminants. One group of such XOCs are the heavily used chloroacetanilide herbicides. We have found that chloroacetanilide herbicides are rapidly dechlorinated in water, sand, and soil by thiosulfate salts under ambient conditions. Structural and kinetics analysis suggests that the reaction occurred by S(N)2 nucleophilic substitution, in which the chlorine was replaced by thiosulfate and the herbicide was detoxified. Laboratory studies showed that this reaction could be used for removing residues of chloroacetanilide herbicides in water, soil, and sand. Our findings also suggest that some other XOCs may be subject to this reaction. Because common thiosulfate salts are innocuous products (e.g., fertilizers) and the reaction selectively detoxifies XOCs at low thiosulfate levels, this discovery may lead to a new way for safe removal of certain XOCs from the environment.

Acetamides↗

PubMed2002

Oxidation of diazinon by anodic Fenton treatment.

Anodic Fenton treatment (AFT) is a new technology that has several advantages over classic Fenton treatment and electrochemical Fenton treatment. The oxidation of diazinon by AFT using different electrolytes has been investigated. NaCl, KCl and Na2SO4 show similar effects on the extent and rate of oxidation, and the data can be fitted quite well by the AFT kinetics model. Use of NaNO3 as the electrolyte causes low-efficiency electrolysis and a subsequent low oxidation rate for diazinon. The NaCl concentration level in the anodic half-cell and the concentration ratio between the two half-cells is optimized at 0.04M and 4:1 (cathodic/anodic), respectively. The activation energy of diazinon oxidation by anodic Fenton treatment is estimated to be 12.6 +/- 0.6 kJ mol(-1), which is less than half of that for aqueous chlorine treatment. Diazoxon is the intermediary oxidation product. The oxidation of diazinon as a formulated product has also been investigated. Its dissipation kinetics can also be fitted quite well by the AFT model. Compared with the oxidation of pure diazinon, the oxidation rate of formulated diazinon is much lower, an indication that many formulation ingredients compete with diazinon for reaction with the hydroxyl radical.

Diazinon↗

PubMedDate not supplied

Kinetic effect of humic acid on alachlor degradation by anodic Fenton treatment.

Contamination of water often results from the heavy use of agricultural chemicals, and the disposal of aqueous pesticide waste is a concern. Anodic Fenton treatment (AFT) has been shown to be a successful remediation method for pesticides in solution, but the effect of soil on the degradation kinetics of pesticides using this method has not been determined. The purpose of this study was to study the effect of humic acid, as a soil surrogate, on the degradation kinetics of alachlor [2-chloro-N-(2,6-diethylphenyl-N-(methoxymethyl) acetamide], a heavily used herbicide that has been studied in pure aqueous solution by AFT. The AFT consists of a controlled constant delivery of Fenton reagents, using an electrochemical half-cell to deliver ferrous iron. Alachlor was quickly degraded by AFT, and the kinetics were found to obey the previously developed AFT model well. Degradation of alachlor by AFT in humic acid slurry showed that when the amount of humic acid was increased, alachlor degradation was significantly slowed down and the degradation kinetics were shifted from the AFT model to a first-order model. Further experimentation indicated that humic acid not only competes with alachlor for hydroxyl radicals, reducing the degradation rate of the target compound, but also buffers the slurry at near neutral pH, blocking regeneration of ferrous ion from ferric ion and subsequently shifting the kinetics to first order. Degradation of several other pesticides in humic acid slurry also followed first-order kinetics. These results imply that higher concentrations of Fenton reagents will be required for soil remediation.

Acetamides↗