UV 30†fs laser pulse generation using a multi-pass cell.

Ultrashort ultraviolet (UV) pulses are pivotal for resolving ultrafast electron dynamics. However, their efficient generation is strongly impeded by material dispersion and two-photon absorption, in particular, if pulse durations around a few tens of femtoseconds or below are targeted. Here, we present a new (to our knowledge) approach to ultrashort UV pulse generation: using the fourth-harmonic generation output of a commercial ytterbium laser system delivering 220 fs UV pulses, we implement a multi-pass cell (MPC) providing 5.6 µJ pulses at 256 nm, compressed to 30.5 fs. Our results set a short-wavelength record for MPC post-compression while offering attractive options to navigate the trade-off between upconversion efficiency and acceptance bandwidth for UV pulse production.

Hypoperfusion of Amygdala in Chronic Migraine: An Exploratory Quantitative Perfusion Imaging Using 3D Pseudo-Continuous Arterial Spin Labeling.

BACKGROUND: Although the amygdala has structural and functional abnormalities in Chronic Migraine (CM), less is known about the altered perfusion of the amygdala in CM. OBJECTIVE: The current study aimed to assess amygdala perfusion in CM using a contrast agent-free and quantitative approach. METHODS: 15 Normal Controls (NC) and 13 patients with CM during the migraine interval were assessed for brain structure and subjected to 3D Pseudo- Continuous Arterial Spin Labeling (3D-PCASL) MR imaging. The Cerebral Blood Flow (CBF) value of the amygdala was automatically extracted based on the individual amygdala mask for all participants. The independent sample t-test, Receiver Operating Characteristic (ROC) curve, and correlation analysis were used to evaluate the perfusion changes in CM. RESULTS: Bilateral amygdala cerebral perfusion was lower in CM (left amygdala, 42.21±4.49 ml/100mg/min; right amygdala, 42.38±4.41 ml/100mg/min) than in NC (left amygdala, 48.31±6.92 ml/100mg/min; right amygdala, 47.88±6.53 ml/100mg/min) (left, p = 0.01; right, p = 0.02). There was no significant correlation between the perfusion of bilateral amygdalas and the clinical variables. Also, there was no significant difference in the volume of bilateral amygdalas between the two groups. The Area Under the Curve (AUC) of the CBF values of the left and right amygdala was 0.78 (95%CI: 0.58-0.91) and 0.75 (95%CI: 0.55-0.89), respectively. The cut-off value was 44.24 ml/100mg/min (left amygdala, with sensitivity 76.90% and specificity 78.70%) and 46.75 ml/100mg/min (right amygdala, with sensitivity 92.3% and specificity 58.80%), respectively. CONCLUSION: CM presented bilateral hypoperfusion in the amygdala, offering potential diagnostic value in distinguishing CM from NC. The 3D-PCASL could be regarded as a simple and efficient neuroimaging tool to assess the perfusion status in CM patients.

Mitochondria and NLRP3 inflammasome in cardiac hypertrophy.

Cardiac hypertrophy is the main adaptive response of the heart to chronic loads; however, prolonged or excessive hypertrophy promotes myocardial interstitial fibrosis, systolic dysfunction, and cardiomyocyte death, especially aseptic inflammation mediated by NLRP3 inflammasome, which can aggravate ventricular remodeling and myocardial damage, which is an important mechanism for the progression of heart failure. Various cardiac overloads can cause mitochondrial damage. In recent years, the mitochondria have been demonstrated to be involved in the inflammatory response during the development of cardiac hypertrophy in vitro and in vivo. As the NLRP3 inflammasome and mitochondria are regulators of inflammation and cardiac hypertrophy, we explored the potential functions of the NLRP3 inflammasome and mitochondrial dysfunction in cardiac hypertrophy. In particular, we proposed that the induction of mitochondrial dysfunction in cardiomyocytes may promote NLRP3-dependent inflammation during myocardial hypertrophy. Further in-depth studies could prompt valuable discoveries regarding the underlying molecular mechanisms of cardiac hypertrophy, reveal novel anti-inflammatory therapies for cardiac hypertrophy, and provide more desirable therapeutic outcomes for patients with cardiac hypertrophy.

High-efficiency supercontinuum generation in solid thin plates at 0.1 TW level.

Supercontinuum generation in a solid-state medium was investigated experimentally. A continuum covering 460 to 950 nm was obtained when 0.8 mJ/30 fs Ti:sapphire laser pulses were applied to seven thin fused silica plates at a 1 kHz repetition rate. The primary processes responsible for spectral broadening were self-phase modulation (SPM) and self-steepening, while SPM and self-focusing were balanced to optimize the spectral broadening and suppress the multiphoton process. The output was compressed to a 5.4 fs and a 0.68 mJ pulse, corresponding to two optical cycles and 0.13 TW of peak power.

Hydrological regulation drives regime shifts: evidence from paleolimnology and ecosystem modeling of a large shallow Chinese lake.

Quantitative evidence of sudden shifts in ecological structure and function in large shallow lakes is rare, even though they provide essential benefits to society. Such 'regime shifts' can be driven by human activities which degrade ecological stability including water level control (WLC) and nutrient loading. Interactions between WLC and nutrient loading on the long-term dynamics of shallow lake ecosystems are, however, often overlooked and largely underestimated, which has hampered the effectiveness of lake management. Here, we focus on a large shallow lake (Lake Chaohu) located in one of the most densely populated areas in China, the lower Yangtze River floodplain, which has undergone both WLC and increasing nutrient loading over the last several decades. We applied a novel methodology that combines consistent evidence from both paleolimnological records and ecosystem modeling to overcome the hurdle of data insufficiency and to unravel the drivers and underlying mechanisms in ecosystem dynamics. We identified the occurrence of two regime shifts: one in 1963, characterized by the abrupt disappearance of submerged vegetation, and another around 1980, with strong algal blooms being observed thereafter. Using model scenarios, we further disentangled the roles of WLC and nutrient loading, showing that the 1963 shift was predominantly triggered by WLC, whereas the shift ca. 1980 was attributed to aggravated nutrient loading. Our analysis also shows interactions between these two stressors. Compared to the dynamics driven by nutrient loading alone, WLC reduced the critical P loading and resulted in earlier disappearance of submerged vegetation and emergence of algal blooms by approximately 26 and 10 years, respectively. Overall, our study reveals the significant role of hydrological regulation in driving shallow lake ecosystem dynamics, and it highlights the urgency of using multi-objective management criteria that includes ecological sustainability perspectives when implementing hydrological regulation for aquatic ecosystems around the globe.

Current status and historical variations of phthalate ester (PAE) contamination in the sediments from a large Chinese lake (Lake Chaohu).

The residual levels of phthalate esters (PAEs) in the surface and two core sediments from Lake Chaohu were measured with a gas chromatograph-mass spectrometer (GC-MS). The temporal-spatial distributions, compositions of PAEs, and their effecting factors were investigated. The results indicated that di-n-butyl phthalate (DnBP), diisobutyl phthalate (DIBP), and di(2-ethylhexyl) phthalate (DEHP) were three dominant PAE components in both the surface and core sediments. The residual level of total detected PAEs (∑PAEs) in the surface sediments (2.146 ± 2.255 µg/g dw) was lower than that in the western core sediments (10.615 ± 9.733 µg/g) and in the eastern core sediments (5.109 ± 4.741 µg/g). The average content of ∑PAEs in the surface sediments from the inflow rivers (4.128 ± 1.738 µg/g dw) was an order of magnitude higher than those from the lake (0.323 ± 0.093 µg/g dw), and there were similar PAE compositions between the lake and inflow rivers. This finding means that there were important effects of PAE input from the inflow rivers on the compositions and distributions of PAEs in the surface sediments. An increasing trend was found for the residual levels of ΣPAEs, DnBP, and DIBP from the bottom to the surface in both the western and eastern core sediments. Increasing PAE usage with the population growth, urbanization, and industrial and agricultural development in Lake Chaohu watershed would result in the increasing production of PAEs and their resulting presence in the sediments. The significant positive relationships were also found between the PAE contents and the percentage of sand particles, as well as TOC contents in the sediment cores.

Toxic Effects of Ethyl Cinnamate on the Photosynthesis and Physiological Characteristics of Chlorella vulgaris Based on Chlorophyll Fluorescence and Flow Cytometry Analysis.

The toxic effects of ethyl cinnamate on the photosynthetic and physiological characteristics of Chlorella vulgaris were studied based on chlorophyll fluorescence and flow cytometry analysis. Parameters, including biomass, F(v)/F(m) (maximal photochemical efficiency of PSII), Ф(PSII) (actual photochemical efficiency of PSII in the light), FDA, and PI staining fluorescence, were measured. The results showed the following: (1) The inhibition on biomass increased as the exposure concentration increased. 1 mg/L ethyl cinnamate was sufficient to reduce the total biomass of C. vulgaris. The 48-h and 72-h EC50 values were 2.07 mg/L (1.94-2.20) and 1.89 mg/L (1.82-1.97). (2) After 24 h of exposure to 2-4 mg/L ethyl cinnamate, the photosynthesis of C. vulgaris almost ceased, manifesting in Ф(PSII) being close to zero. After 72 h of exposure to 4 mg/L ethyl cinnamate, the Fv /Fm of C. vulgaris dropped to zero. (3) Ethyl cinnamate also affected the cellular physiology of C. vulgaris, but these effects resulted in the inhibition of cell yield rather than cell death. Exposure to ethyl cinnamate resulted in decreased esterase activities in C. vulgaris, increased average cell size, and altered intensities of chlorophyll a fluorescence. Overall, esterase activity was the most sensitive variable.

Distribution, partitioning and sources of polycyclic aromatic hydrocarbons in the water-SPM-sediment system of Lake Chaohu, China.

The residual levels of polycyclic aromatic hydrocarbons (PAHs) in the water, suspended particular matter (SPM) and sediment from Lake Chaohu were measured with a gas chromatograph-mass spectrometer (GC-MS). The spatial-temporal distributions and the SPM-water partition of PAHs and their influencing factors were investigated. The potential sources and contributions of PAHs in the sediment were estimated by positive matrix factorization (PMF) and probabilistic stable isotopic analysis (PSIA). The results showed that the average residual levels of total PAHs (PAH16) in the water, SPM and sediment were 170.7 ± 70.8 ng/L, 210.7 ± 160.7 ng/L and 908.5 ± 1878.1 ng/g dry weight, respectively. The same spatial distribution trend of PAH16 in the water, SPM and sediment was found from high to low: river inflows>western lake>eastern lake>water source area. There was an obvious seasonal trend of PAH16 in the water, while no obvious seasonal trend was found in the SPM. The residues and distributions of PAHs in the water, SPM and sediment relied heavily on carbon content. Significant Pearson correlations were found between LogKoc and LogKow as well as some hydro-meteorological factors. Three major sources of PAHs including coal and biomass combustions, and vehicle emissions were identified.

Atmospheric PBDEs at rural and urban sites in central China from 2010 to 2013: residual levels, potential sources and human exposure.

Atmospheric polybrominated diphenyl ethers (PBDEs) were monitored monthly from 2010 to 2013 at rural and urban sites near a large shallow Chinese lake (Lake Chaohu). The urban areas had higher air PBDEs than the rural areas because of endogenic pollution. The highest and lowest concentrations of Σ13BDEs were observed in the winter and in the summer, respectively. A weak temperature dependence and significant positive correlations between certain PBDE congeners and the PM10 (p < 0.01) suggest transport with particulate matter. Using air-mass back-trajectories, we determined that the main sources of the PBDEs were the areas to the north, such as Shandong Province, and to the east, such as Zhejiang Province. PBDEs did not pose an appreciable risk to human health based on the inhalation exposure assessment. The residents in urban areas were exposed to higher levels of PBDEs, and wintertime exposures posed the greatest human health risk.

Organochlorine pesticides in the dust fall around Lake Chaohu, the fifth largest lake in China.

The residual levels of organochlorine pesticides (OCPs) in the dust fall around Lake Chaohu were measured using gas chromatography mass spectrometry from April 2010 to March 2011. The fluxes, components, temporal-spatial variations, and sources of OCPs were also analyzed. Twenty-one types of OCPs were detected in the dust fall samples around Lake Chaohu, with a total concentration of 51.54 ± 36.31 ng/g and a total flux of 10.01 ± 13.69 ng/(m(2) day). Aldrin (35.3 %), endosulfan (39.1 %), dichlorodiphenyltrichloroethanes (DDTs) (49.8 %), and isodrin (37.1 %) were the major OCPs in the spring, summer, autumn, and winter, respectively. Both the residual level and the flux were higher in the spring than in other seasons and higher at the outer lake sampling sites than inner lake sampling site. The potential source of the hexachlorcyclohexanes in the dust fall may be recent lindane usage. The DDTs mainly came from historical dicofol usage, and a significant input of DDT was found during April and June. The presence of endosulfan may be due to the present use of technical endosulfan. The aldrin in the dust might be due to its occasional usage, and isodrin may be a result of long-distance transport from other countries.

Water quality benchmarking (WQB) and priority control screening (PCS) of persistent toxic substances (PTSs) in China: necessity, method and a case study.

The priority control screening (PCS) and water quality benchmarking (WQB) of toxic chemicals in water are key steps to ensure the safety of drinking water and aquatic ecosystem that is the crucial goal of water environment management. Owing to the different levels of social-economic development in different countries and regions, the PCS and WQB of toxic chemicals must be determined in accordance with their specific water environment situations. However, in China, the PCS and WQB of toxic chemicals in water were mainly introduced from the other countries. A method for the PCS and WQB of toxic chemicals in water based on the ecological risks was proposed, and a platform named Bayesian Matbugs Calculator (BMC) was developed. As a case study, the WQB and PCS of sixty-nine PTSs based their ecological risks were performed on the basis of one-year monthly monitoring in Lake Chaohu. The results showed that the current national water quality criteria (WQC) would underestimate the toxicological risk to organisms in this aquatic ecosystem. It appears necessary to develop new WQC for the protection of aquatic organisms in Lake Chaohu. Four grades of priority control chemicals (PCCs) in Lake Chaohu were proposed. The highest priority was assigned to organonitrogen-phosphorus pesticides, including parathion, dichlorvos, malathion, omethoate, and di-n-butyl phthalate. However, the national "blacklist" of toxic compounds only covered 7 of 20 PCCs, indicating that the other 13 PCCs would not be controlled efficiently. Because the pollution pattern of PTSs in various water bodies might be quite different, we appealed to the governments to screen the regional PPC lists or develop a more comprehensive national list for aquatic ecosystem protection in China.

Polybrominated diphenyl ethers (PBDEs) in the surface sediments and suspended particulate matter (SPM) from Lake Chaohu, a large shallow Chinese lake.

Suspended particulate matter (SPM) and surface sediment samples were collected from Lake Chaohu to investigate the residues, congener profile, and spatial distribution of polybrominated diphenyl ethers (PBDEs) in a large shadow lake in the middle of the Yangtze River Basin. The concentration of Σ13BDEs (defined as the sum of 13 target congeners excluding BDE 209) and the concentration of BDE 209 ranged from 236.7 to 1373.4 pg/g dry weight (dw) and from 4.2 to 691.2 pg/g dw in the surface sediments, respectively, which were 2-3 orders of magnitude smaller than those found in the SPM. The congener composition was dominated by BDE 47 (50.8%) and BDE 209 (21.3%) in the sediment, while the proportion of BDE 47 to Σ14BDEs in the SPM was slightly higher than that in the sediment. The concentration of Σ14BDEs in the sediment from the drinking water source (WR) area in the eastern part of the lake was very low, with a mean value of 514.8 pg/g, whereas the mean concentration was 102.4 ng/g in the SPM. A cluster analysis (CA) was conducted to further illustrate the dominance of each congener and the similarity of each sampling site. Many factors, including resuspension, photodecomposition, microbial oxidation, local discharge, and dredging, influenced the distribution in the sediment and SPM for the PBDE congeners as well as the spatial distribution of PBDEs. A formula for the PBDE concentrations in the surface sediment and SPM was constructed to understand the potential relationship between sediment and SPM concentrations. Although the formula did not accurately predict specific PBDE congener concentrations in the sediment, it remains a practical and useful way to assess the overall pollution of PBDE in sediment in Lake Chaohu, as it depends only on the concentrations of PBDEs in the SPM.

Spatio-temporal distributions and the ecological and health risks of phthalate esters (PAEs) in the surface water of a large, shallow Chinese lake.

The spatio-temporal distributions and the ecological and health risks of PAEs in surface water of Lake Chaohu, the fifth largest lake in China, were studied based on the monthly monitoring of six PAE congeners from May 2010 to April 2011. The annual total concentration of the six PAE congeners (Σ6PAE) in the surface water ranged from 0.467 to 17.953 µg L(-1), with the average value of 4.042±3.929 µg L(-1). The di-n-butyl phthalate (DnBP) that dominated the Σ6PAE at 65.8% was found at its highest and lowest levels in the western lake (TX) and eastern drinking water source area (JC), respectively. The temporal distributions of Σ6PAE showed that the highest and lowest levels were observed in September 2010 and June 2010, respectively. The different relationships between the runoff and the PAEs with low and high levels of carbon might suggest their different sources. The DnBP had much greater ecological risks than the other studied PAE congeners as indicated by its potential affected fractions (PAFs) and the margin of safety (MOS10). The PAE congeners studied posed little health risk to the nearby male and female citizens.

Silver-zwitterion organic-inorganic nanocomposite with antimicrobial and antiadhesive capabilities.

In this work, we demonstrate a convenient, efficient, and environmentally benign strategy to achieving antimicrobial and antiadhesive purposes using a silver-zwitterion nanocomposite. The synthesis of the nanocomposite relies on loading zwitterionic polymer brushes with Ag(+) precursor ions, followed by their in situ reduction to Ag nanoparticle by ultraviolet (UV) irradiation. Both poly(sulfobetaine methacrylate) (pSBMA) and poly(carboxybetaine methacrylate) (pCBMA) have been studied as matrices for the embedding of silver. Well-dispersed silver nanoparticles are embedded into pCBMA matrices. The obtained pCBMA-silver hybrid (CB-Ag) is capable of killing bacteria upon contact and releasing dead bacteria under wet conditions. Results suggest the feasibility of using this nanocomposite system as a robust and reliable antimicrobial and antiadhesive platform for the prevention of microbial colonization.

Differentiation of BMMSCs into odontoblast-like cells induced by natural dentine matrix.

OBJECTIVE: To assess the odontogenic potential of bone marrow mesenchymal stem cells (BMMSCs) to differentiate into odontoblast-like cells under the morphogenetic influence of dentine matrix as a possible basis for new stem cell-mediated therapeutic approaches to pulp diseases. DESIGN: BMMSCs were harvested from the whole bone marrow and cells at passages 3-5 were used for subsequent experiments. For in vitro studies, 1×10(4) cells were seeded on the surface of dentine slabs and co-cultured for 2 weeks in 24-well plates, then fixed, decalcified, embedded in paraffin and serial sections were processed for analyses. Haematoxylin-eosin (HE) staining was used for the morphological analysis of BMMSCs on the dentine slabs. The protein expression of dentine sialoprotein (DSP) in co-cultured BMMSCs was detected by immunohistochemical (IHC) staining. For in vivo studies, 5×10(6) cells were collected as cell pellets, seeded onto dentine slices and transplanted into renal capsules for 6 weeks. Histological analyses of harvested tissues were performed as described for the in vitro studies. Total RNA and protein were extracted from harvested tissues and Dspp/DSP expression was investigated by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. RESULTS: After 2 weeks of co-culture with dentine slabs, BMMSCs demonstrated good viability in terms of morphological appearance and some showed polarization and extension of their cytoplasmic processes into dentine tubules with DSP expression. In vivo study demonstrated similar morphological changes and DSP expression in cells adjacent to dentine. RT-PCR and Western blot also demonstrated that the expression of Dspp/DSP in the co-cultured BMMSCs groups was higher than in the control groups. CONCLUSION: Dentine matrix can signal morphogenic induction of differentiation of BMMSCs into odontoblast-like cells in vivo and in vitro.

Water-gas exchange of organochlorine pesticides at Lake Chaohu, a large Chinese lake.

Organochlorine pesticides (OCPs), a potential threat to ecosystems and human health, are still widely residual in the environment. The residual levels of OCPs in the water and gas phase were monitored in Lake Chaohu, a large Chinese lake, from March 2010 to February 2011. Nineteen types of OCPs were detected in the water with a total concentration of 7.27 ± 3.32 ng/l. Aldrin, DDTs and HCHs were the major OCPs in the water, accounting for 38.3%, 28.9% and 23.6% of the total, respectively. The highest mean concentration (12.32 ng/l) in the water was found in September, while the lowest (1.74 ng/l) was found in November. Twenty types of gaseous OCPs were detected in the atmosphere with a total concentration of 542.0 ± 636.5 pg/m(3). Endosulfan, DDTs and chlordane were the major gaseous OCPs in the atmosphere, accounting for 48.9%, 22.5% and 14.4% of the total, respectively. The mean concentration of gaseous OCPs was significantly higher in summer than in winter. o,p'-DDE was the main metabolite of DDT in both the water and gas phase. Of the HCHs, 52.3% existed as ß-HCH in the water, while α-HCH (37.9%) and γ-HCH (30.9%) were dominant isomers in the gas phase. The average fluxes were -21.11, -3.30, -152.41, -35.50 and -1314.15 ng/(m(2) day) for α-HCH, γ-HCH, HCB, DDT and DDE, respectively. The water-gas exchanges of the five types of OCPs indicate that water was the main potential source of gaseous OCPs in the atmosphere. A sensitivity analysis indicated that the water-gas flux of α-HCH, γ-HCH and DDT is more vulnerable than that of HCB and DDE to the variation of the parameters. The possible source of the HCHs in the water was from the historical usage of lindane; however, that in the air was mainly from the recent usage of lindane. The technical DDT and dicofol might be the source of DDTs in the water and air.

Levels, temporal-spatial variations, and sources of organochlorine pesticides in ambient air of Lake Chaohu, China.

The residual levels of OCPs in the gas phase and particle phase in Lake Chaohu, China, were measured using GC-MS from March 2010 to February 2011. The temporal-spatial variations and sources of OCPs were also analyzed. Twenty types of OCPs were detected in the gas phase with a total concentration of 484.8 ± 550.4 pg/m³. Endosulfan, DDTs and chlordane were the primary OCPs in the gas phase. The mean concentration of OCPs in the gas phase was significantly higher in the summer than in the winter. Seventeen types of OCPs were detected in the particle phase with a total concentration of 18.3 ± 26.1 pg/m³. DDTs were major OCPs in the particle phase. The mean concentration of OCPs in the particle phase decreased at first and then increased during the period. The potential source of the HCHs in ambient air of Lake Chaohu might come from recent lindane usage. DDTs mainly came from historical dicofol usage, and an input of DDT was observed in the spring, which may result from the present use of marine paint that contains technical DDT. Endosulfan and chlordane in the air may be due to the present use of technical endosulfan and chlordane.

Residues, distributions, sources, and ecological risks of OCPs in the water from Lake Chaohu, China.

The levels of 18 organochlorine pesticides (OCPs) in the water from Lake Chaohu were measured by a solid phase extraction-gas chromatography-mass spectrometer detector. The spatial and temporal distribution, possible sources, and potential ecological risks of the OCPs were analyzed. The annual mean concentration for the OCPs in Lake Chaohu was 6.99 ng/L. Aldrin, HCHs, and DDTs accounted for large proportions of the OCPs. The spatial pollution followed the order of Central Lakes > Western Lakes > Eastern Lakes and water area. The sources of the HCHs were mainly from the historical usage of lindane. DDTs were degraded under aerobic conditions, and the main sources were from the use of technical DDTs. The ecological risks of 5 OCPs were assessed by the species sensitivity distribution (SSD) method in the order of heptachlor > γ-HCH > p,p'-DDT > aldrin > endrin. The combining risks of all sampling sites were MS > JC > ZM > TX, and those of different species were crustaceans > fish > insects and spiders. Overall, the ecological risks of OCP contaminants on aquatic animals were very low.

Simulation of the fate and seasonal variations of α-hexachlorocyclohexane in Lake Chaohu using a dynamic fugacity model.

Fate and seasonal variations of α-hexachlorocyclohexane (α-HCH) were simulated using a dynamic fugacity model in Lake Chaohu, China. Sensitivity analyses were performed to identify influential parameters and Monte Carlo simulation was conducted to assess model uncertainty. The calculated and measured values of the model were in good agreement except for suspended solids, which might be due to disregarding the plankton in water. The major source of α-HCH was an input from atmospheric advection, while the major environmental outputs were atmospheric advection and sediment degradation. The net annual input and output of α-HCH were approximately 0.294 t and 0.412 t, respectively. Sediment was an important sink for α-HCH. Seasonal patterns in various media were successfully modeled and factors leading to this seasonality were discussed. Sensitivity analysis found that parameters of source and degradation were more important than the other parameters. The sediment was influenced more by various parameters than air and water were. Temperature variation had a greater impact on the dynamics of the model output than other dynamic parameters. Uncertainty analysis showed that the model uncertainty was relatively low but significantly increased in the second half of the simulation period due to the increase in the gas-water diffusion flux variability.