Institute of Oceanography

BACKGROUND: Pharmaceuticals are known to contaminate tap water worldwide, but the relevant human health risks have not been assessed in China. OBJECTIVES: We monitored 32 pharmaceuticals in Chinese tap water and evaluated the life-long human health risks of exposure in order to provide information for future prioritization and risk management. METHODS: We analyzed samples (n = 113) from 13 cities and compared detected concentrations with existing or newly-derived safety levels for assessing risk quotients (RQs) at different life stages, excluding the prenatal stage. RESULTS: We detected 17 pharmaceuticals in 89% of samples, with most detectable concentrations (92%) at < 50 ng/L. Caffeine (median-maximum, nanograms per liter: 24.4-564), metronidazole (1.8-19.3), salicylic acid (16.6-41.2), clofibric acid (1.2-3.3), carbamazepine (1.3-6.7), and dimetridazole (6.9-14.7) were found in ≥ 20% of samples. Cities within the Yangtze River region and Guangzhou were regarded as contamination hot spots because of elevated levels and frequent positive detections. Of the 17 pharmaceuticals detected, 13 showed very low risk levels, but 4 (i.e., dimetridazole, thiamphenicol, sulfamethazine, and clarithromycin) were found to have at least one life-stage RQ ≥ 0.01, especially for the infant and child life stages, and should be considered of high priority for management. We propose an indicator-based monitoring framework for providing information for source identification, water treatment effectiveness, and water safety management in China. CONCLUSION: Chinese tap water is an additional route of human exposure to pharmaceuticals, particularly for dimetridazole, although the risk to human health is low based on current toxicity data. Pharmaceutical detection and application of the proposed monitoring framework can be used for water source protection and risk management in China and elsewhere.

Abstract: Selenium nanoparticles (SeNPs), as a special form of selenium (Se) supplement, have attracted worldwide attention due to their favorable properties and unique bioactivities. Herein, an eco-friendly and economic way to prepare stable SeNPs is introduced. SeNPs were synthesized in aqueous chitosan (CTS) and then embedded into CTS microspheres by spray-drying, forming selenium nanoparticles-loaded chitosan microspheres (SeNPs-M). The physicochemical properties including morphology, elemental state, size distribution and surface potential were investigated. Institute of Cancer Research mice were used as model animal to evaluate the bioactivities of SeNPs-M. Trigonal-phase SeNPs of ~35 nm were synthesized, and SeNPs-M physically embedding those SeNPs were successfully prepared. Amazingly, acute toxicity test indicated that SeNPs-M were much safer than selenite in terms of Se dose, with a LD 50 of around 18-fold of that of selenite. In addition, SeNPs-M possessed powerful antioxidant activities, as evidenced by a dramatic increase of both Se retention and the levels of glutathione peroxidase, superoxide dismutase and catalase. The design of SeNPs-M can offer a new way for further development of SeNPs with a higher efficacy and better biosafety. Thus, SeNPs-M may be a potential candidate for further evaluation as an Se supplement with antioxidant properties and be used against Se deficiency in animals and human beings. Keywords: selenium, nano, microsphere, chitosan, antioxidant

High phytoplankton biomass often occurs in plumes near river mouths or in eutrophic coastal waters for short time periods. However, we observed an increased phytoplankton biomass in a narrow jet-shaped protrusion into the western South China Sea (SCS) using satellite chlorophyll a (chl a) data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and concurrent ship measurements in 1999. In June, regional phytoplankton biomass appeared as a large jet shape extending from the coastal waters of Vietnam eastward towards the SCS, about 200 km northeast of the mouth of the Mekong River; this feature intensified in the form of a large jet or gyre from July to September, decayed in October, and disappeared entirely in November. The gyre was about 400 km in diameter with chl a concentrations from 0.5 to 2 mg m -3 . Data on sea surface temperature (SST), winds, and sea surface height anomalies indicated a strong offshore upwelling during a period of strong southwesterly winds alongshore. The upwelling coincided with the regional increase in phytoplankton biomass in terms of shape, timing, and location. We observed this phenomenon during every southwesterly monsoon season from 1997 to 2002 using chl a images from 3 satellite ocean color sensors -SeaWiFS, Ocean Color and Temperature Scanner (OCTS), and Ocean Color Imager (OCI) -and it appeared to be related to the cross-shelf upwelling that delivers nutrients to surface waters. The phytoplankton then flowed with a large anticyclonic gyre into the western SCS.

Harmful algal blooms (HABs) in the southeastern Vietnamese coastal waters have caused large economic losses in aquacultured and wild fisheries in recent years; however, there have been few oceanographic studies on these HAB events. The present study reports an extensive HAB off southeastern Vietnamese waters during late June to July 2002 with in situ observations and analyzes the oceanographic conditions using satellite remote sensing data. The HAB had high chlorophyll a (Chl a ) concentrations (up to 4.5 mg m −3 ) occurring ∼200 km off the coast and ∼200 km northeast of the Mekong River mouth for a period of ∼6 weeks. The bloom was dominated by the harmful algae haptophyte Phaeocystis cf. globosa and caused a very significant mortality of aquacultured fish and other marine life. In the same period, sea surface temperature (SST) imagery showed a cold water plume extending from the coast to the open sea, and QuikScat data showed strong southwesterly winds blowing parallel to the coastline. This study indicated that the HAB was induced and supported by offshore upwelling that brings nutrients from the deep ocean to the surface and from coastal water to offshore water and that the upwelling was driven by strong wind through Ekman transport when winds were parallel to the coastline. This study demonstrated the possibility of utilizing a combination of satellite data of Chl a , SST, and wind velocity together with coastal bathymetric information and in situ observations to give a better understanding of the biological oceanography of HABs.

The electrocatalytic reduction of naturally abundant N2 to NH3 is an attractive approach to replace the Haber-Bosch nitrogen-fixation process that causes enormous energy consumption and greenhouse gas emissions. However, designing high-performance catalysts toward the electrocatalytic N2 reduction reaction (eNRR) remains one of the greatest challenges in this area. Herein, high-throughput screening of catalysts for the NRR among a series of transition metal atoms supported on a defective hexagonal boron nitride (h-BN) nanosheet is performed through spin-polarized density functional theory (DFT) computations. Strikingly, among the 18 candidates, the V/Tc atom anchored on a defective h-BN monolayer (V@BN and Tc@BN) showed good NRR activity with relatively low onset potentials. Particularly, V@BN was found to exhibit outstanding catalytic activity for the NRR via an enzymatic pathway with an extremely low overpotential of 0.25 V. The value is significantly lower than that on the Ru (0001) stepped surface that has the best NRR catalytic performance among bulk metal catalysts. The novel NRR activity of V@BN is attributed to the enhanced electrical conductivity due to V-doping, the "donation-backdonation" process for N2 activation, and the highly centralized spin-polarization on the V atom. This work not only provides a quite promising catalyst for the NRR but also provides new insights for the rational design of single-atom NRR catalysts.

Measurements of aerosol bulk composition, optical depth, size distribution and the incoming solar radiation flux were carried out over the coastal waters of India, the Arabian sea and the tropical Indian Ocean during a cruise conducted in January 1996. Aerosol concentrations were relatively high throughout much of the cruise, even when the ship was at considerable distances from land. In this paper, we link the observed spatial variations and meridional gradients in the measurements to monsoonal and inter-hemispheric transport across the ITCZ using a high resolution global reanalysis that highlights the winter monsoon. We show that the northeast monsoonal low level flow can transport sulfates, mineral dust and other aerosols from the Indian sub-continent to the ITCZ within 6–7 days. These transports result in an increase the aerosol optical depth (AOD) at the equator by as much as 0.2 and a decrease in the solar radiative forcing at the sea surface by about 10–20 Wm-2. The high concentrations of continental aerosols are a result of three factors: strong (about 6–10 m/s) near-surface northerly flow; a shallow boundary layer of about 400 to 800 m thick, which traps the pollutants; subsidence, associated with the northeast monsoon, which suppresses rainfall over most of the Arabian sea and thus minimizes the wet removal process. In addition dust can be transported in the middle troposphere from the Arabian desert to the cruise region 4000 km away with a transit time of 2–3 days. There is strong evidence of interhemispheric transports effected by eddies that wrap around the ITCZ. These eddies bring clean southern hemisphere air to about 10°N in the Indian Ocean and carry polluted continental air into the southern-hemisphere. In this manner, substantial amounts of aerosols and other pollutants can be routinely transported to the southern-hemisphere Indian Ocean during the northeast monsoon. Thus, in order to understand the connection between continental emissions and impacts over the Indian Ocean, it is necessary to focus on the róle of the northeast monsoon in the large-scale atmospheric circulation over this region.

activation and conversion, while the PI-COFs not only act as a photosensitizer to generate charge carriers but also exert a promoting effect on the selectivity. The optimized PI-COF with a triazine ring exhibits excellent activity and selectivity. A possible intra- and inter-molecular charge-transfer mechanism was proposed, in which the photogenerated electrons in PI-COFs are efficiently separated from the central ring to the diimide linkage, and then transferred to the single Ni active sites, as evidenced by theoretical calculations.

Atmospheric concentrations of aluminium, an indicator of dust substances, have been determined in a set of high-volume aerosol particle samples collected at different locations over continental China and over the China Sea. High concentrations of dust were observed in northern continental China, and at certain locations such as Beijing dust may include an anthropogenic fraction. The mass particle-size distributions of dust varied depending on its distance from source regions, with the mass median diameter for Al of ~1.6-5.9 μm at Beijing in northern China and ~ 1.9 μm over off-shore areas of the East China Sea. Model-predicted mean dry deposition velocities of dust particles are from 1.4 to 4.8 cm s-1 over northern continental China and from 1.4 to 2.1 cm s-1 over the China Sea. Atmospheric deposition models have been applied to estimate the atmospheric fluxes and deposition of dust at different locations. The estimated atmospheric flux of dust at Xi’an of the Loess Plateau is 25 (4.9 to 44) g m-2 mo-1 which is the highest among the regions we studied. The estimated present-day dust flux is comparable to the late quaternary records of eolian dust accumulation at this site. The total atmospheric deposition of dust to the China Sea is 67 Tg yr-1, accounting for 14% of the total atmospheric deposition of dust to the entire North Pacific. With such a high deposition rate, Asian dust may play an important rôle in biogeochemical cycles of trace substances in the Asia/North Pacific region.

We infer global and regional emissions of five of the most abundant hydrofluorocarbons (HFCs) using atmospheric measurements from the Advanced Global Atmospheric Gases Experiment and the National Institute for Environmental Studies, Japan, networks. We find that the total CO2-equivalent emissions of the five HFCs from countries that are required to provide detailed, annual reports to the United Nations Framework Convention on Climate Change (UNFCCC) increased from 198 (175-221) Tg-CO2-eq ⋅ y(-1) in 2007 to 275 (246-304) Tg-CO2-eq ⋅ y(-1) in 2012. These global warming potential-weighted aggregated emissions agree well with those reported to the UNFCCC throughout this period and indicate that the gap between reported emissions and global HFC emissions derived from atmospheric trends is almost entirely due to emissions from nonreporting countries. However, our measurement-based estimates of individual HFC species suggest that emissions, from reporting countries, of the most abundant HFC, HFC-134a, were only 79% (63-95%) of the UNFCCC inventory total, while other HFC emissions were significantly greater than the reported values. These results suggest that there are inaccuracies in the reporting methods for individual HFCs, which appear to cancel when aggregated together.

The influence of the Mekong River (South China Sea) on N 2 fixation and phytoplankton distribution was investigated during the lowest‐ and highest‐discharge seasons (April 2007 and September 2008, respectively). The river plays an essential role in providing nutrients (nitrate, phosphate, silicate) for the adjacent sea and creates different salinity and nutrient gradients over different seasons. River water (salinity 0), mesohaline waters (salinity 14–32), a transition zone with salinities between 32 and 33.5, and marine waters (salinity above 33.5) were sampled at different spatial resolutions in both cruises. High N 2 fixation rates were measured during both seasons, with rates of up to 5.05 nmol N L −1 h −1 in surface waters under nitrogen‐replete conditions, increasing to 22.77 nmol N L −1 h −1 in nitrogen‐limited waters. Asymbiotic diatoms were found only close to the river mouth, and symbiotic diatoms, which potentially hosted diazotrophs, were most abundant in waters where N 2 fixation rates were highest, nitrate concentrations were at the detection limit, and phosphate and silicate were still available. Filamentous cyanobacteria like Trichodesmium were present only in marine waters with salinities above 33.5. Overall, N 2 fixation accounts for 1‐47% of the nitrogen demand of primary production.

This study is an attempt to produce an assessment of the impact of shrimp aquaculture in the Mekong Delta (Viet Nam) on mangrove ecosystems. For this exercise we selected two sub-areas (Ca Mau and Tra Vinh provinces) encompassing a variety of land uses and ecological conditions. Twenty stations in Tra Vinh and 15 stations in Ca Mau have been surveyed several times from September 2000 to March 2002. Field investigations included mangrove soils studies, measurements of pH and salinity of the water, analysis of mangrove flora, and density and structure of the vegetation. Four Syst@me Probatoire de l'Observation de la Terre (SPOT) scenes were used for the discrimination of mangrove types and for the delineation of landscape units. For the first time, five ecologically distinct landscape classes were identified and delineated. Their possible links with the farming and yields of high valued species of shrimps, especially the giant tiger shrimp (Penaeus monodon) destined for export markets, need further studies. Since 1965, about 30% of mangrove ecosystems have been lost in Ca Mau Province and more than 30% of present mangroves are replanted monospecific stands. To the best of our knowledge, this is the first study which demonstrates that, in spite of deep and ancient man interactions in the Mekong Delta, five ecologically distinct classes of land use can be defined. Satellite surveys confirm a clear distribution of landscape units with possible links with shrimp aquaculture potentialities.

Plankton metabarcoding is increasingly implemented in marine ecosystem assessments and is more cost-efficient and less time-consuming than monitoring based on microscopy (morphological). 18S rRNA gene is the most widely used marker for groups’ and species’ detection and classification within marine eukaryotic microorganisms. These datasets have commonly relied on the acquisition of organismal abundances directly from the number of DNA sequences (i.e. reads). Besides the inherent technical biases in metabarcoding, the largely varying 18S rRNA gene copy numbers (GCN) among marine protists (ranging from tens to thousands) is one of the most important biological biases for species quantification. In this work, we present a gene copy number correction factor (CF) for four marine planktonic groups: Bacillariophyta, Dinoflagellata, Ciliophora miscellaneous and flagellated cells. On the basis of the theoretical assumption that ‘1 read’ is equivalent to ‘1 GCN’, we used the GCN median values per plankton group to calculate the corrected cell number and biomass relative abundances. The species-specific absolute GCN per cell were obtained from various studies published in the literature. We contributed to the development of a species-specific 18S rRNA GCN database proposed by previous authors. To assess the efficiency of the correction factor we compared the metabarcoding, morphological and corrected relative abundances (in cell number and biomass) of 15 surface water samples collected in the Belgian Coastal Zone. Results showed that the application of the correction factor over metabarcoding results enables us to significantly improve the estimates of cell abundances for Dinoflagellata, Ciliophora and flagellated cells, but not for Bacillariophyta. This is likely to due to large biovolume plasticity in diatoms not corresponding to genome size and gene copy numbers. C-biomass relative abundance estimations directly from amplicon reads were only improved for Dinoflagellata and Ciliophora. The method is still facing biases related to the low number of species GCN assessed. Nevertheless, the increase of species in the GCN database may lead to the refinement of the proposed correction factor.

A new and general method for the synthesis of β-azidophosphonates has been achieved through Mn(OAc)3-mediated radical oxidative phosphonation-azidation of alkenes. The starting materials of P(O)-H compounds, alkenes, and azidotrimethylsilane are stable and cheap. This method can be easily adapted for large-scale preparation.

The general method for the tandem phosphination-decarboxylation-oxidation of alkynyl acids under aerobic conditions has been developed. In the presence of CuSO4·5H2O and TBHP, the reactions provide a novel access to β-ketophosphine oxides in good to excellent yields. This transformation allows the direct formation of a P-C bond and the construction of a keto group in one reaction.

Seahorses (Hippocampus spp) are heavily exploited in Vietnam, but conservation and management measures are currently limited by the ambiguous taxonomic definitions of the genus in the region. Seven species of seahorse are identified in this paper as inhabiting the coastal waters of Vietnam. We used morphometric and DNA sequence data (from the cytochrome b region of the mitochondrial genome) to delimit the species. Species descriptions are put forward and we provide illustrations and an identification key to the species. The species are provisionally assigned to Hippocampus spinosissimus Weber 1913, H. comes Cantor 1850, H. trimaculatus Leach 1814, H. kuda Bleeker 1852, H. kelbggi Jordan and Snyder 1902, H. mohnikei Bleeker 1854 and H. histrix Kaup 1856. The current level of confusion in seahorse nomenclature means that some of these distinct species in Vietnam (in particular H. spinosissimus, H. kuda, H. kelloggi and H. mohnikei) may have to be renamed once a comprehensive revision of the genus has been completed.

BACKGROUND/AIMS: Salvianolic acid B (Sal B), a major polyphenolic compound of Salvia miltiorrhiza Bunge, has been shown to possess potential antidiabetic activities. However, the action mechanism of SalB in type 2 diabetes has not been investigated extensively. The present study was designed to investigate the effects of Sal B on diabetes-related metabolic changes in a spontaneous model of type 2 diabetes, as well as its potential molecular mechanism. METHODS: Male C57BL/KsJ-db/db mice were orally treated with Sal B (50 and 100 mg/kg) or metformin (positive drug, 300 mg/kg) for 6 weeks. RESULTS: Both doses of Sal B significantly decreased fasting blood glucose, serum insulin, triglyceride and free fatty acid levels, reduced hepatic gluconeogenic gene expression and improved insulin intolerance in db/db mice. High dose Sal B also significantly improved glucose intolerance, increased hepatic glycolytic gene expression and muscle glycogen content, and ameliorated histopathological alterations of pancreas, similar to metformin. Sal B treatment resulted in increased phosphorylated AMP-activated protein kinase (p-AMPK) protein expression in skeletal muscle and liver, increased glucose transporter 4 (GLUT4) and glycogen synthase protein expressions in skeletal muscle, and increased peroxisome proliferator-activated receptor alpha (PPARα) and phosphorylated acetyl CoA carboxylase (p-ACC) protein expressions in liver. CONCLUSION: Our data suggest that Sal B displays beneficial effects in the prevention and treatment of type 2 diabetes at least in part via modulation of the AMPK pathway.

Variations in oxygen uptake with variations in temperature were measured on undisturbed salt‐marsh muds taken from Georgia, the Bay of Fundy, and the eastern shore of Nova Scotia. Mud temperatures were measured in the marsh. Natural temperature variations were about twice as great in Georgia as in Nova Scotia. Q 10 values for respiration determined in any one season varied from 1 to 4, tending to be lower in southern marshes and marshes located nearer low water level. In all marshes, seasonal changes of mud respiration were correlated with changes in energy supply and with temperature. Considering periods of days or weeks rather than months, the southern mud organisms show more stability under conditions of changing temperature than the northern ones. This may be due to better stirring by large animals and the absence of freezing in the south.

The U.S. Geological Survey, Multi Hazards Demonstration Project (MHDP) uses hazards science to improve resiliency of communities to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages emergency planners, businesses, universities, government agencies, and others in preparing for major natural disasters. The project also helps to set research goals and provides decision-making information for loss reduction and improved resiliency. The first public product of the MHDP was the ShakeOut Earthquake Scenario published in May 2008. This detailed depiction of a hypothetical magnitude 7.8 earthquake on the San Andreas Fault in southern California served as the centerpiece of the largest earthquake drill in United States history, involving over 5,000 emergency responders and the participation of over 5.5 million citizens.

In this work, novel thin-film nanocompostie NF membranes were developed through modification with maleic anhydride functionalized graphene oxide<italic>via</italic>interfacial polymerization, which showed the enhanced water flux with retaining high salt rejection.

A metal-free and K₂S₂O₈-mediated radical addition/cyclization of internal alkynes leading to benzo[<italic>b</italic>]phosphole oxides was developed, which eliminates residual heavy metal contamination in the product.