¹²⁹I and its species in the East China Sea: level, distribution, sources and tracing water masses exchange and movement

Anthropogenic I-129 as a long-lived radioisotope of iodine has been considered as an ideal oceanographic tracer due to its high residence time and conservative property in the ocean. Surface water samples collected from the East China Sea (ECS) in August 2013 were analyzed for I-129, I-127 and their inorganic chemical species in the first time. The measured I-129/I-127 ratio is 1-3 orders of magnitude higher than the pre-nuclear level, indicating its dominantly anthropogenic sources. Relatively high I-129 levels were observed in the Yangtze River and its estuary, as well as in the southern Yellow Sea, and I-129 level in seawater declines towards the ECS shelf. In the open sea, I-129 and I-127 in surface water exists mainly as iodate, while in Yangtze River estuary and some locations, iodide is dominated. The results indicate that the Fukushima nuclear accident has no detectable effects in the ECS until August 2013. The obtained results are used for investigation of interaction of various water masses and water circulation in the ECS, as well as the marine environment in this region. Meanwhile this work provides essential data for evaluation of the possible influence of the increasing NPPs along the coast of the ECS in the future

Fingerprinting Sediment Transport in River-Dominated Margins Using Combined Mineral Magnetic and Radionuclide Methods

Both magnetic properties and radionuclides are widely used to trace sediment transport in aquatic environments; however, these methods have not been used in combination. In this study, the East China Sea (ECS), a typical river-dominated margin, was chosen to demonstrate the advantages of combining these two methods to track sediment movements on a seasonal to annual timescale. The ratios between saturation isothermal remnant magnetization and anhysteretic remnant magnetization (χARM/SIRM) and 7Be/210Pbex activity ratios as well as mass balance of 7Be provide information on the seasonal transport of sediment from the Changjiang Estuary to the neighboring shelf. Both 210Pb budget and SIRM distribution in the inner shelf of the ECS show that a small fraction (at most 14% of annual Changjiang sediment discharge) of particles could be transported offshore. Most of 7Be activities in inner shelf sediments of the ECS were below detection limit due to relatively lower residence times and dilution by the older sediment. The observation that radionuclide activities exhibit a better correlation with χARM/SIRM ratios than with grain size suggests that iron oxides are the primary carriers of 7Be, 210Pb, and 234Th. The absorption of radionuclides onto magnetic minerals further reinforces the reliability of this combined approach in tracing sediment transport. Our study indicates that radionuclides, with different half-lives, can be utilized for quantifying sediment dynamics, whereas magnetic properties can yield more detailed information on sediment transport directions. The combined analysis of magnetic parameters and radionuclides offers a better understanding of sediment transport in river-dominated areas

Insulin resistance predicts progression of de novo atherosclerotic plaques in patients with coronary heart disease: a one-year follow-up study

BACKGROUND: The aim of our study was to explore and evaluate the relationship between insulin resistance and progression of coronary atherosclerotic plaques. With the great burden coronary heart disease is imposing on individuals, healthcare professionals have already embarked on determining its potential modifiable risk factors in the light of preventive medicine. Insulin resistance has been generally recognized as a novel risk factor based on epidemiological studies; however, few researches have focused on its effect on coronary atherosclerotic plaque progression. METHODS: From June 7, 2007 to December 30, 2011, 366 patients received their index coronary angiogram and were subsequently found to have coronary atherosclerotic plaques or normal angiograms were consecutively enrolled in the study by the department of cardiology at the Ruijin Hospital, which is affiliated to the Shanghai Jiaotong University School of Medicine. All patients had follow-up angiograms after the 1-year period for evaluating the progression of the coronary lesions. The modified Gensini score was adopted for assessing coronary lesions while the HOMA-IR method was utilized for determining the state of their insulin resistance. Baseline characteristics and laboratory test results were described and the binomial regression analysis was conducted to investigate the relationship between insulin resistance and coronary atherosclerotic plaque progression. RESULTS: Index and follow-up Gensini scores were similar between the higher insulin lower insulin resistant groups (9.09 ± 14.33 vs 9.44 ± 12.88, p = 0.813 and 17.21 ± 18.46 vs 14.09 ± 14.18, p =0.358). However the Gensini score assessing coronary lesion progression between both visits was significantly elevated in the higher insulin resistant group (8.13 ± 11.83 versus 4.65 ± 7.58, p = 0.019). Multivariate logistic binomial regression analysis revealed that insulin resistance (HOMA-IR > 3.4583) was an independent predictor for coronary arterial plaque progression (OR = 4.969, p = 0.011). We also divided all the participants into a diabetic (n = 136) and a non-diabetic group (n = 230), and HOMA-IR remained an independent predictor for atherosclerosis plaque progression. CONCLUSIONS: Insulin resistance is an independent predictor of atherosclerosis plaque progression in patients with coronary heart disease in both the diabetic and non-diabetic population

Detection of Linkage Between Solar and Lunar Cycles and Runoff of the World\u27s Large Rivers

It is an ongoing concern that global hydrological cycle can be likely intensified under context of climate change and anthropogenic actions. Here, our results show that the solar and lunar periodic motions (SLPMs) have substantial impact on the runoff of the world\u27s large rivers. We estimate that SLPMs can produce a change of the world\u27s large rivers runoff by as much as 6.7%. Although climate models suggest that the increased frequency of extreme events is attributed to anthropogenic activities, it is out of our expectation that as much as 73% and 85% of the extreme flood and drought events (based on runoff discharged to the ocean) appear in resonance with SLPMs, respectively. A reevaluation of impacts of SLPMs on changes in the world\u27s river runoff is urgently needed, especially when extreme drought and flood events are on the rise

Static and Kinetic Studies of the Adsorption/Desorption of H and OH Ions on Alumina in Aqueous NaNO Solution

The adsorption/desorption of H + and OH − ions under static conditions on to alumina in aqueous NaNO 3 solution was studied at 30°C by potentiometric titration and calculations undertaken using the triple layer model (TLM). Intrinsic dissociation constants and intrinsic complexation constants at 30°C were used to calculate surface charge density, surface potential and surface species as a function of pH and ionic strength (I). Related adsorption/desorption studies of H + and OH − ions under dynamic conditions on to alumina in aqueous NaNO 3 solution were studied by means of the concentration-jump technique. Mechanistic information regarding H + and OH − ion adsorption/desorption on to alumina was discussed using the experimental data in conjunction with the TLM

Plutonium Isotopes Research in the Marine Environment: A synthesis

Plutonium (Pu) isotopes are one of most important artificial radionuclides. Recent advance in analytical methodology of Pu have made Pu play a vital role in tracing the transport of biogenic elements and pollutants, sediment deposition/resuspension and other marine process. The various atom ratios of Pu isotopes (238Pu, 239Pu, 240Pu and 241Pu) depending on the sources of Pu are useful to identify the contribution of different sources and these atom ratios can be utilized to indicate the marine process. The aim of this manuscript is to provide an overview of the application of Pu for various processes in the marine environment, such as determination of recent sedimentation rate, indicating sediment transport and deposition/resuspension, and water mass transport, etc, based on the knowledge of analytical methodology advance and geochemical behavior of Pu. Furthermore, it is expected to provide new insights into broadening the application of Pu in the marine environment and help to better understand the land-sea interaction and global climate change

Submarine groundwater discharge enhances primary productivity in the Yellow Sea, China: Insight from the separation of fresh and recirculated components

Submarine groundwater discharge (SGD) is being increasingly recognized as a significant source of nutrient into coastal waters, and generally comprises two components: submarine fresh groundwater discharge (SFGD) and recirculated saline groundwater discharge (RSGD). The separate evaluation of SFGD and RSGD is extremely limited as compared to the conventional estimation of total SGD and associated nutrient fluxes, especially in marginal-scale regions. In this study, new high-resolution radium isotopes data in seawater and coastal groundwater enabled an estimation of SGD flux in a typical marginal sea of the Yellow Sea. By establishing 226Ra and 228Ra mass balance models, we obtained the SGD-derived radium fluxes, and then estimated the SFGD and RSGD fluxes through a two end-member model. The results showed that the total SGD flux into the Yellow Sea was equivalent to approximately 6.6 times the total freshwater discharge of surrounding rivers, and the SFGD flux accounted for only 5.2%–8.8% of the total SGD. Considering the nutrient concentrations in coastal fresh and saline groundwater, we obtained the dissolved inorganic nutrient fluxes (mmol m−2 yr−1) to be 52–353 for nitrogen (DIN), 0.21–1.4 for phosphorus (DIP), 34–226 for silicon (DSi) via SFGD, and 69–262 for DIN, 1.0–3.9 for DIP, 70–368 for DSi via RSGD, with the sum of nutrient fluxes equaling to (1.8–9.3)-fold, (1.3–5.6)-fold and (2.0–9.5)-fold of the riverine inputs. Compared to the conventional estimation of the total SGD flux, the nutrient fluxes derived from the separation of SFGD and RSGD were (1.6–2.1), (1.6–1.8) and (4.0–4.9) times lower for DIN, DIP and DSi, respectively, indicating that the estimates by separating SFGD and RSGD could be conservative and representative results of the Yellow Sea. Furthermore, we suggested that SGD played an important role in nutrient sources among all the traditional nutrient inputs sources, providing 15%–48%, 33%–68% and 14%–43% of the total DIN, DIP and DSi input fluxes into the Yellow Sea, and the high nutrient stoichiometric ratios (i.e., DIN/DIP) in SGD probably contributed to the increasing ratios in the Yellow Sea. In addition delivering large amounts of nutrient into the Yellow Sea, SGD would create primary productivity of 10–49, 1.6–6.8 and 8.8–42 g C m−2 yr−1 based on N, P and Si, which were equivalent to 5.2%–27%, 0.9%–3.7% and 4.7%–23% of the total primary productivity, respectively. In particular, the SFGD-derived DIN flux can be converted to primary productivity of 4.2–28 g C m−2 yr−1 thus demonstrating the disproportionately large role of SFGD in ecological environment of the Yellow Sea relative to its flux. Therefore, we conclude that SGD, particularly SFGD, plays an important role as a nutrient source for the Yellow Sea, and not only affects nutrient budgets and structures but also enhances the primary productivity