Search

The Ulva prolifera bloom is considered one of the most serious ecological disasters in the Yellow Sea in the past decade, forming a carbon sink in its source area within a short period but becoming a carbon source at its destination. To explore the effects of different environmental changes on seawater dissolved carbon pools faced by living U. prolifera in its originating area, U. prolifera were cultured in three sets with different light intensity (54, 108, and 162 μmol m−2 s−1), temperature (12, 20, and 28 °C) and nitrate concentration gradients (25, 50, and 100 μmol L−1). The results showed that moderate light (108 μmol m−2 s−1), temperature (20 °C), and continuous addition of exogenous nitrate significantly enhanced the absorption of dissolved inorganic carbon (DIC) in seawater by U. prolifera and most promoted its growth. Under the most suitable environment, the changes in the seawater carbonate system were mainly dominated by biological production and denitrification, with less influence from aerobic respiration. Facing different environmental changes, U. prolifera continuously changed its carbon fixation mode according to tissue δ13C results, with the changes in the concentrations of various components of DIC in seawater, especially the fluctuation of HCO 3 − and CO 2 concentrations. Enhanced light intensity of 108 μmol m−2 s−1 could shift the carbon fixation pathway of U. prolifera towards the C 4 pathway compared to temperature and nitrate stimulation. Environmental conditions at the origin determined the amount of dissolved carbon fixed by U. prolifera. Therefore, more attention should be paid to the changes in marine environmental conditions at the origin of U. prolifera , providing a basis for scientific management of U. prolifera. [Display omitted] • Moderate light, temperature and nitrate addition boost U. prolifera DIC absorption. • U. prolifera adapts carbon fixation modes to environmental changes. • Origin environmental conditions determine U. prolifera's carbon sink contribution. [ABSTRACT FROM AUTHOR]

• NOx in wetlands was mainly generated from vegetation-covered sediments. • Denitrifiers dominated NO production, showing sensitivity to environmental gradients. • NO emissions would be underestimated without considering tidal pulses. Intertidal wetland sediments are an important source of atmospheric nitrogen oxides (NO x), but their contribution to the global NO x budget remains unclear. In this work, we conducted year-round and diurnal observations in the intertidal wetland of Jiaozhou Bay to explore their regional source-sink patterns and influence factors on NO x emissions (initially in the form of nitric oxide) and used a dynamic soil reactor to further extend the mechanisms underlying the tidal pulse of nitric oxide (NO) observed in our investigations. The annual fluxes of NO x in the vegetated wetland were significantly higher than those in the wetland without vegetation. Their annual variations could be attributed to changes in temperature and the amount of organic carbon in the sediment, which was derived from vegetated plants and promoted the carbon-nitrogen cycle. Anaerobic denitrifiers had advantages in the intertidal wetland sediment and accounted for the major NO production (63.8 %) but were still limited by nitrite and nitrate concentrations in the sediment. Moreover, the tidal pulse was likely a primary driver of NO x emissions from intertidal wetlands over short periods, which was not considered in previous investigations. The annual NO exchange flux considering the tide pulse contribution (8.93 ± 1.72 × 10–2 kg N ha–1 yr–1) was significantly higher than that of the non-pulse period (4.14 ± 1.13 × 10–2 kg N ha–1 yr–1) in our modeling result for the fluxes over the last decade. Therefore, the current measurement of NO x fluxes underestimated the actual gas emission without considering the tidal pulse. [Display omitted] [ABSTRACT FROM AUTHOR]

The carbonate chemistry in river-dominated marginal seas is highly heterogeneous, and there is ongoing debate regarding the definition of atmospheric CO 2 source or sink. On this basis, we investigated the carbonate chemistry and air-sea CO 2 fluxes in a hotspot estuarine area: the Changjiang Estuary during winter and summer. The spatial characteristics of the carbonate system were influenced by water mixing of three end-members in winter, including the Changjiang freshwater with low total alkalinity (TA) concentration, the less saline Yellow Sea Surface Water with high TA, and the saline East China Sea (ECS) offshore water with moderate TA. While in summer with increased river discharge, the carbonate system was regulated by simplified two end-member mixing between the Changjiang freshwater and the ECS offshore water. By performing the end-member mixing model on DIC variations in the river plume region, significant biological addition of DIC was found in winter with an estimation of −120 ± 113 μmol kg−1 caused by wintertime organic matter remineralization from terrestrial source. While this biological addition of DIC shifted to DIC removal due to biological production in summer supported by the increased nutrient loading from Changjiang River. The p CO 2 dynamics in the river plume and the ECS offshore were both subjected to physical mixing of freshwater and seawater, whether in winter and summer. In the inner estuary without horizontal mixing, the p CO 2 dynamics were mainly influenced by biological uptake in winter and temperature in summer. The inner estuary, the river plume, and the ECS offshore were sources of atmospheric CO 2 , with their contributions varying seasonally. The Changjiang runoff enhanced the inner estuary's role as a CO 2 source in summer, while intensive biological uptake reduced the river plume's contribution. [Display omitted] • Mixing of end-members drove the variation of carbonate system among seasons. • Winter biological DIC addition and summer DIC removal occurred in the rive plume. • The important role of freshwater inputs in CO 2 emissions from the Changjiang estuary. [ABSTRACT FROM AUTHOR]

Abstract: In order to process large numbers of explicit knowledge documents such as patents in an organized manner, automatic document categorization and search are required. In this paper, we develop an intelligent retrieval system for patent analysis that helps companies manage patent documents more effectively. By composing both bibliographic coupling and text mining approaches, this paper proposes a hybrid structure for higher search accuracy. An experimental prototype called PRAP (Patent Retrieval and Analysis Platform) was developed. Testing indicates that the PRAP has significantly increased the accuracy of patent retrieval compared to traditional patent search methods. We believed that our works have provided a feasible architecture for an intelligent patent retrieval system. [Copyright &y& Elsevier]

Myocardial remodeling is the key step in the development of ischemic cardiomyopathy. We aimed to compare effects of renal denervation (RDN) with those of angiotensin receptor neprilysin inhibitors (ARNi) on cardiac remodeling after myocardial infarction (MI), and explore underlying mechanism. Sprague-Dawley rats (n = 40; male) were subjected to ligation of left anterior descending coronary artery to induce MI; six rats served as controls. ARNi was administered at a dose of 60 mg/kg/day for 4 weeks starting 1 week after MI. An RDN/Sham-RDN procedure was performed 1 week after MI. Rats in all groups were studied 5 weeks after MI. Echocardiography was used to evaluate cardiac function. Masson staining and TUNEL staining were used to determine the extent of cardiac remodeling. Indicators of oxidative stress in heart and brain were used to analyze the potential mechanisms involved. Five weeks after MI, both RDN and ARNi significantly improved cardiac function and cardiac remodeling; however, RDN was superior to ARNi at attenuating myocardial apoptosis. Compared to ARNi, RDN was also more effective at decreasing the abnormal oxidative stress caused by MI; this was especially true in case of the brain and was confirmed by evaluating the changes in reactive oxygen species (ROS) levels and other oxidative stress parameters following MI. RDN is not inferior to ARNi with respect to the improvement of cardiac remodeling in rats with ischemic cardiomyopathy. The effect of RDN might be associated with effective inhibition of oxidative stress in both the heart and brain. [ABSTRACT FROM AUTHOR]