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We developed a dimethylsulfide (DMS) module coupled to an ecological dynamics model studying the annual DMS cycle of the Yellow and East China seas (YECS). The model results showed that surface DMS concentrations ([DMS]) peaked in August along the coast, and there exhibited several DMS peaks offshore annually. In addition, surface [DMS] were higher in the Yellow Sea than that in the East China Sea. The annual mean surface [DMS] of the YECS reached to 4.55 nmol/L, and oceanic DMS emissions from this sea area was 6.78 μmol/(m2 day). Several sensitivity experiments demonstrated that phytoplankton community and sea water temperature exerted crucial effects on seasonal variations of surface [DMS]; and phytoplankton community or temperature changed the timing of surface DMS peak while photolysis affected the magnitude of [DMS]. Moreover, the effect size of phytoplankton community or water temperature varied spatially.

Understanding the sources, compositions and degradation states of sedimentary organic matter (SOM) in estuarine regions can provide significant information about regional carbon and nitrogen cycles. Amino acids (AAs), amino sugars (ASs), total organic carbon (TOC), total nitrogen (TN) and stable carbon isotopic composition (δ13OC) were investigated in six sediment cores of the Changjiang Estuary. The concentrations of ASs ranged from 0.60 to 3.11 μmol g-1, and accounted for 1.7 ± 0.7% of TOC and 2.1 ± 0.9% of TN. The concentrations of AAs ranged from 5.18 to 11.66 μmol g-1 and accounted for 8.1 ± 1.7% of TOC and 17.4 ± 3.9% of TN. Relatively coarse and fresh SOM was mainly deposited in the nearshore (e.g., station B6), whereas fine and degraded SOM occurred in the offshore area (e.g., station A7-4). The relationships between median grain size and AA-C% and degradation index (DI) revealed that fine-grained particles adsorbed older SOM, but sandy sediments were correlated with relatively fresh SOM. Diatoms were the main contributor of marine SOM and high primary production increased the burial of fresh SOM. TOC and TN contents and their degradation states did not exhibit distinct trends with core depth, possibly due to frequent vertical disturbance. Additionally, bacterial OM contributed 0.4–23.7% to TOC and 0.6–30.6% to TN in the sediment cores. The hypoxia of the water might have further promoted the proportion of bacterial OM in the sediments.

An efficient approach to install deuterium into mono-fluorinated (hetero)arenes by a Ag2CO3/Sphos-mediated HIE protocol with D2O as the deuterium source has been disclosed. This method showed a specific site selectivity of deuteration at the α-position of the fluorine atom, which is complementary to the existing transition metal-catalyzed HIE process.

The spatial distributions, fluxes, and environmental effects of non-methane hydrocarbons (NMHCs) were investigated in the Yellow Sea (YS) and the East China Sea (ECS) in spring. The average concentrations of ethane, propane, i-/n-butane, ethylene, propylene and isoprene in the seawater were 18.1 ± 6.4, 15.4 ± 4.7, 6.8 ± 2.9, 6.4 ± 3.2, 67.1 ± 26.7, 20.5 ± 8.7 and 17.1 ± 11.1 pmol L−1, respectively. The alkenes in the surface seawater were more abundant than their saturated homologs and NMHCs concentrations (with the exception of isoprene) decreased with carbon number. The spatial variations of isoprene were consistent with the distributions of chlorophyll a (Chl-a) and Chaetoceros, Skeletonema, Nitzschia mainly contributed to the production of isoprene, while the others’ distributions might be related to their photochemical production. Observations in atmospheric NMHCs indicated alkanes in the marine atmosphere decreased from inshore to offshore due to influence of the continental emissions, while alkenes were largely derived from the oceanic source. In addition, no apparent diurnal discrepancy of atmospheric NMHCs (except for isoprene) were found between daytime and night. As the main sink of NMHCs in seawater, the average sea-to-air fluxes of ethane, propane, i-/n-butane, ethylene and propylene were 31.70, 29.75, 18.49, 15.89, 239.6, 67.94 and 52.41 nmol m−2 d−1, respectively. The average annual emissions of isoprene accounted for 0.1–1.3% of the global ocean emissions, which indicated that the coastal and shelf areas might be significant sources of isoprene. Furthermore, this study represents the first effort to estimate the environmental effects caused by NMHCs over the YS and the ECS and the results demonstrated contributions of alkanes to ozone and secondary organic aerosol (SOA) formation were lower than those of the alkenes and the largest contributor was isoprene.

Dimethylsulfoniopropionate (DMSP) is widespread in the oceans, and its biological metabolite, dimethyl sulfide (DMS), plays an important role in the atmosphere. The Antarctic region has become a hotspot in DMS studies due to the high spatial and temporal variability in DMS(P) concentration, but the level of bacterial DMS production remains unclear. In this study, a bacterium isolated from Antarctic floating ice, Rhodococcus sp. NJ-530, was found to metabolize DMSP into DMS, and the rate of DMS production was measured as 3.96 pmol·mg protein-1 ·h-1 . Rhodococcus sp. NJ-530 had a DddD-Rh enzyme containing two CaiB domains, which belonged to the CoA-transferase III superfamily. However, the DddD-Rh had a molecular weight of 73.21 kDa, which was very different from previously characterized DddD enzymes in sequence and evolution. In vitro assays showed that DddD-Rh was functional in the presence of acetyl-CoA. This was the first functional DddD from Gram-positive Actinobacteria. Moreover, a quantitative real-time polymerase chain reaction revealed that high temperature facilitated the expression of dddD-Rh, and changes of salinity had little effect on it. This study adds new evidence to the bacterial DMS production in the Southern Ocean and provides a basis for investigating the metabolic mechanism of DMSP in extreme environments.

Concentrations and diurnal variations of inorganic nutrients (dissolved inorganic nitrogen (DIN), phosphate (PO4-P) and silicate (SiO3-Si)), as well as chlorophyll a (Chl-a) were determined in the subsurface water (SSW) and surface microlayer (SML) of the Bohai and Yellow Seas in summer 2015. The concentrations of DIN, SiO3-Si and Chl-a (except for PO4-P) in the SML were respectively correlated with their concentrations in the SSW, indicating that a major source of substances in the SML could be transported from the SSW. The enrichment factor (EF) was defined as the ratio of the concentration in the SML to that in the corresponding SSW. There was little difference in concentrations of PO4-P between the SML and the SSW samples by nonparametric difference test (P > 0.05). DIN, SiO3-Si and Chl-a (except for PO4-P) were found to be enriched in the SML relative to the SSW, with average EFs of 2.45, 1.18 and 2.37, respectively. No connection was identified between nutrients EFs and wind speed for our entire data. DIN, SiO3-Si, PO4-P and Chl-a concentrations in the SSW and the SML exhibited strong diurnal variations at an anchor station.

The spatial distribution, chemical composition and ecological risk of 16 phthalate esters (PAEs) were investigated in the sea-surface microlayer (SML), seawater and sediment samples of the Bohai Sea (BS) and the Yellow Sea (YS). The concentration levels of the ΣPAEs spanned a range of 449–13441 ng L−1 in the SML, 453–5108 ng L−1 in seawater, and 1.24–15.8 mg kg−1 in the sediment samples, respectively, with diisobutyl phthalate (DiBP), di-n-butyl phthalate (DBP) and di-ethylhexyl phthalate (DEHP) as the dominant PAEs in both the water and sediment samples. The concentrations of ΣPAEs in the BS were higher than those in the YS. The vertical distribution of ΣPAEs in the water column showed that the concentrations were higher in the surface waters, but decreased slightly with depth, and started to increase at the bottom. Additionally, PAEs were significantly enriched in the SML, with an average enrichment factor of 1.46. The ecological risk of the PAEs was evaluated by the risk quotient (RQ) method, which indicated that DEHP posed a high risk to aquatic organisms in the whole water-phase, while the RQ values of DBP and DiBP reached a high risk levels in sedimentary environment.

Spatiotemporal variability in seawater, spatial variation in sediment, pollution characteristics, and risks related to 16 phthalate esters (PAEs) were investigated in the Yangtze River estuary and its adjacent East China Sea. The total concentrations of ΣPAEs in surface water were 0.588–17.7 μg L−1 in summer, 2.63–22.9 μg L−1 in winter, and 1.93–20.7 μg L−1 in spring, with average values of 2.05, 10.2, and 4.89 μg L−1, respectively. PAE concentrations exhibited notable seasonal variations with the highest value in winter and the lowest value in summer. The seasonal variation in PAE concentrations may be influenced by runoff and diluted water from the Yangtze River. The chemical composition of PAEs showed that di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and di(2-ethylhexyl) phthalate (DEHP) had significantly higher (p

Marine isoprene concentrations in the East China Sea were measured during two oceanographic cruises: one from October 10, 2013 to November 21, 2013 and another from May 16, 2014 to June 13, 2014. Mean (range) isoprene concentrations in the surface water in the study area were 32.85 (16.31–108.2) pmol L−1 in late spring and 26.83 (11.22–42.13) pmol L−1 in autumn. The isoprene concentrations showed seasonal variation and were higher in late spring, which could be attributable to terrigenous diluted water and seasonal variations of phytoplankton structure. Isoprene and chlorophyll a (Chl-a) concentrations were significantly correlated in late spring and autumn even under complex hydrographic conditions. Isoprene and Chl-a concentrations also exhibited similar variations during a 25 h period and remained high during daytime. Analysis of depth profiles indicated that isoprene concentrations in the water column peaked at the surface layer and gradually decreased with increasing depth. The atmospheric concentration of isoprene (average: 53.4 ppt; range: 14.8–141 ppt) was high in the onshore area but low in the offshore area in late spring. The mean sea-to-air fluxes of isoprene in the East China Sea were 36.12 (late spring) and 48.34 (autumn) nmol m−2 d−1. Results revealed the substantial isoprene emission from surface seawater, which was also a net source of atmospheric isoprene during the study period.

Distributions and variations of biogenic sulfur compounds including dimethylsulfide (DMS), dissolved and total dimethylsulfoniopropionate (DMSPd and DMSPt) and acrylic acid (AA) were investigated in coastal waters off Qingdao, China during the late-bloom and after-bloom periods of the Ulva prolifera bloom of 2015. DMSPd, DMS and AA concentrations after the bloom were significantly higher than during the late-bloom, but DMSPt concentrations in surface waters began to decrease. High concentrations of these compounds in the surface layer were associated with the bloom, with the exception of increased concentrations of DMSPt in the middle layer as decaying U. prolifera debris settled. The sea-to-air fluxes of DMS were estimated to be 18.08 and 24.24 μmol m−2 d−1 during the late-bloom and after-bloom, and about three times higher than the reported average fluxes of the Yellow Sea, which highlighted the impacts of U. prolifera blooms on DMS emissions.

The structural and photophysical properties of tetradentate Pt(ppzOppz), Pt(ppzOpopy), Pt(ppzOczpy), and Pt(czpyOczpy) have been experimentally and theoretically explored. Single-crystal diffraction measurements provided accurate structural information. Electrochemical and photophysical characterizations revealed internal electronic energy levels in ground and excited states. (Time-dependent) Density functional theory calculation revealed electron distributions in transition processes of S0 → S1 and S1 → T1 → S0. Electronic transition study indicated that Pt(ppzOppz) demonstrated mixed MLCT/LC states and Pt(czpyOczpy) showed MLCT-dominated states in S1 and T1. Both Pt(ppzOpopy) and Pt(ppzOczpy) presented strong delocalized spin transition (DST) during intersystem crossing. Upon frame modification of Pt(ppzOczpy), we found that their S1 and T1 can be independently manipulated. These blue emitters showed a tunable and narrow emission band (the narrowest fwhm was 19 nm) with luminescence efficiency as high a...

The absorption coefficient and fluorescent components of chromophoric dissolved organic matter (CDOM) in the Bohai Sea (BS), Yellow Sea (YS), and East China Sea (ECS) in spring and autumn were analyzed in this study. Excitation–emission matrices (EEMs) combined with parallel factor analysis (PARAFAC) identified three components, namely, humic-like C1, tyrosine-like C2 and tryptophan-like C3. The seasonal variations in the vertical patterns of the CDOM absorption coefficient (aCDOM(355)) and fluorescent components were influenced by the seasonal water mass except for the terrestrial input. The relationship between aCDOM(355) and dissolved organic matter (DOC) was attributed to their own mixing behavior. The correlation of the fluorescent components with DOC was disturbed by other non-conservative processes during the export of CDOM to the open ocean. The different chemical compositions and origins of DOC and CDOM led to variability in carbon-specific CDOM absorption (a*CDOM(355)) and fluorescent component ratios (ICn/IC1). The relationship between a*CDOM(355) and aCDOM(355) demonstrated that dissolved organic matter (DOM) in the BS, but not in the ECS, highly contributed non-absorbing DOC to the total DOC concentration. The photodegradation of dominant terrestrially derived CDOM in the ECS contributed to the positive relationship between a*CDOM(355) and ICn/IC1. By contrast, the abundant autochthonous CDOM in the YS was negatively correlated with ICn/IC1 in autumn. Our established box models showed that water exchange is a potentially important source of the aromatic components in the BS, YS, and ECS. Hence, the seasonal variations in water exchange might contribute to the variability of CDOM chemical composition in the BS, YS, and ECS, and significantly influence the structure and function of their ecosystems.

The distributions and fluxes of the climatically-active gases dimethylsulfide (DMS), isoprene, methyl bromide (CH 3 Br), and methyl iodide (CH 3 I) were measured in the surface waters of the central basin (CB) of the South China Sea (SCS) in July 2014; the possible production pathways of the gases are discussed to evaluate their biological sources and relative contribution to the global climate. The mean concentrations of DMS, isoprene, CH 3 Br, and CH 3 I were 1.76 ± 1.35 nmol L −1 , 6.92 ± 2.68 pmol L −1 , 0.82 ± 0.23 pmol L −1 , and 2.72 ± 0.72 pmol L −1 , respectively. The vertical profiles of the trace gases were similar to that of chlorophyll- a (Chl- a ). The maxima appeared in the euphotic zone and approximately agreed with the Chl- a maximum layer, whereas the concentrations were below the detection limits beneath the euphotic zone. A significant positive correlation (R = 0.590, p a while no correlations occurred between the other gases and Chl- a . The seawater temperature was also an important factor affecting the isoprene and CH 3 I distributions in the study area. The sea-to-air fluxes of DMS, isoprene, and CH 3 I were estimated at 4.36 ± 3.94 μmol m −2 d −1 , 12.38 ± 6.80 nmol m −2 d −1 , and 8.70 ± 4.79 nmol m −2 d −1 , respectively, suggesting that the CB of the SCS was a substantial source of these trace gases to the atmosphere. In contrast, the study area was a net sink of CH 3 Br and its air-to-sea flux was estimated at 1.97 ± 1.44 nmol m −2 d −1 .

Total organic carbon (TOC), total N (TN) and amino acids (AAs, including the bacterial biomarker D-AAs) were determined in sediment cores from the mud belt of the East China Sea (ECS). The concentration of total hydrolyzable AAs (THAAs) ranged from 3.35 to 13.44 µmol/g dry wt (dw) of the sedimentary organic matter (SOM), exhibiting a decreasing trend downcore. Major constituents of the THAAs were glycine (Gly), L-serine (L-Ser), L-alanine (L-Ala), L-glutamic acid (L-Glu) and L-aspartic acid (L-Asp), whereas the D-aspartic acid (D-Asp), D-glutamic acid (D-Glu), D-serine (D-Ser) and D-alanine (D-Ala), along with non-protein AAs (γ-aminobutyric acid and β-alanine) together accounted for ca. 7% of the THAA pool. Given the C/N ratio values, the OM in three cores was predominantly of marine origin. Based on D-Ala yield, bacterial OM represented on average 18% of TOC and ca. 30% of TN. C-normalized THAAss (THAA-C%) was a sensitive indicator of SOM diagenetic alteration in the upper 40 cm of sediment. However, the degradation index (DI) and reactivity index (RI) values for the cores did not exhibit any definite trend, which may indicate that these two indicators were not sensitive in the early stage of sediment degradation. Negative correlation between the D/L ratio of Ala and THAA-C% suggested a close coupling between the extent of degradation and the accumulation and/or selective preservation of bacterial material in the sediments. In addition, correlation between clay content and THAA-C% suggested that fine grained particles played an important role in affecting the quality of SOM.

A novel class of ortho, para-alternating linked polyarenes is synthesized via catalyst-transfer Suzuki coupling polymerization with Pd2(dba)3/t-Bu3P/p-BrC6H4COPh as initiator. Through a series of kinetic studies and MALDI-TOF analysis, the polymerization is shown to proceed in a chain-growth manner. The optical and thermal properties for the ortho, para-alternating linked polyarenes exhibit unusual molecular weight dependence. Thus, the polymer with lower molecular weight (Mn = 6300 g mol−1) emits green fluorescence whereas the one with higher molecular weight (Mn = 13 800 g mol−1) emits blue fluorescence under UV (λ = 360 nm) irradiation. Furthermore, an all-conjugated block copolymer containing a polyfluorene block and the ortho, para-alternating linked block is also successfully prepared, in a one-pot procedure. These results can provide a pathway to obtain polyarenes with precisely controlled structures, hence, desirable properties.

Endogenous hydrogen sulfide (H2S), mainly synthesized by cystathionine β-synthase (CBS) and cystathionine γ-lyase (CTH), has been implicated in regulating placental angiogenesis; however, the underlying mechanisms are unknown. This study was to test a hypothesis that trophoblasts synthesize H2S to promote placental angiogenesis. Human choriocarcinoma-derived BeWo cells expressed both CBS and CTH proteins, while the first trimester villous trophoblast-originated HTR-8/SVneo cells expressed CTH protein only. The H2S producing ability of BeWo cells was significantly inhibited by either inhibitors of CBS (carboxymethyl hydroxylamine hemihydrochloride, CHH) or CTH (β-cyano-L-alanine, BCA) and that in HTR-8/SVneo cells was inhibited by CHH only. H2S donors stimulated cell proliferation, migration, and tube formation in ovine placental artery endothelial cells (oFPAECs) as effectively as vascular endothelial growth factor. Co-culture with BeWo and HTR-8/SVneo cells stimulated oFPAEC migration, which was inhibited by CHH or BCA in BeWo but CHH only in HTR-8/SVneo cells. Primary human villous trophoblasts (HVT) were more potent than trophoblast cell lines in stimulating oFPAEC migration that was inhibited by CHH and CHH/BCA combination in accordance with its H2S synthesizing activity linked to CBS and CTH expression patterns. H2S donors activated endothelial nitric oxide synthase (NOS3), v-AKT murine thymoma viral oncogene homolog 1 (AKT1), and extracellular signal-activated kinase 1/2 (mitogen-activated protein kinase 3/1, MAPK3/1) in oFPAECs. H2S donor-induced NOS3 activation was blocked by AKT1 but not MAPK3/1 inhibition. In keeping with our previous studies showing a crucial role of AKT1, MAPK3/1, and NOS3/NO in placental angiogenesis, these data show that trophoblast-derived endogenous H2S stimulates placental angiogenesis, involving activation of AKT1, NOS3/NO, and MAPK3/1.

Phthalic acid esters (PAEs), as the most important plasticizers, are widely used in the production of plastic products. The accurate analysis of PAEs in seawater and sediment would be of great significance in studying the transformation of PAEs and their ecological effects in marine environment. In this study, the method of gas chromatography-mass spectrum detector coupled with solid-phase microextraction was established to analyze the concentration of PAEs in seawater and sediment, and the experimental conditions, such as extraction time and extraction temperature, were optimized. Under the optimum conditions, the precision of this method was less than 10.0%, and the limits of detection were 0.04–0.32 ng L −1 and 0.12–1.6 μg kg −1 . Except dimethyl phthalate, the recovery of PAEs in seawater and sediment ranged from 68.0% to 114.0% and 76.4% to 105.0%, respectively. Moreover, the concentrations of PAEs measured by the method were 0.270–1.39 μg L −1 and 0.79–34.8 μg kg −1 in seawater and sediment samples of Changjiang River Estuary and its adjacent area, respectively. In conclusion, the analytical method is easy to operate and reduces the extraction volume of seawater. Thus, this method meets the requirements of the analysis of PAEs in coastal seawater and sediment.

The spatial distributions of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), DMSP-lyase activity (DLA) and their controlling factors including nutrients, phytoplankton community and bacterial abundance were investigated in the East China Sea (ECS) during fall from October 19 to November 2, 2015. Diatoms and dinoflagellates dominated the phytoplankton community, while other taxonomic groups were rare and mainly found in the oligotrophic open sea. Affected by the high nutrients concentrations, Chl a, DMS, DMSP and DLA showed high values in eutrophic inshore waters, and decreased from the costal zones to the open sea. Statistical analysis suggested that diatoms and dinoflagellates were the main controlling factors of DMS, DMSP, and DLA in ECS. For size-fractionated samples, a reduced contribution of the microplankton from inshore stations to offshore stations affected by the trophic conditions was noted. Meanwhile, this decrease in microplankton led to an increase in the ratio of DLA contributed by picoplankton and free-living bacteria from the estuary area to the offshore region. The DMS sea-to-air flux was calculated using the equation of Nightingale et al. (Glob Biogeochem Cy 14(1):373–387, 2000), and approximately 2.88 × 10−2 Tg of sulfur was transferred from the sea into the atmosphere in the form of DMS in ECS during fall.

Endogenous hydrogen sulfide (H2S) synthesized via metabolizing L-cysteine by cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CSE) is a potent vasodilator and angiogenic factor. The objectives of this study were to determine if human uterine artery (UA) H2S production increases with augmented expression and/or activity of CBS and/or CSE during the menstrual cycle and pregnancy and whether exogenous H2S dilates UA. Uterine arteries from nonpregnant (NP) premenopausal proliferative (pPRM) and secretory (sPRM) phases of the menstrual cycle and pregnant (P) women were studied. H2S production was measured by the methylene blue assay. CBS and CSE mRNAs were assessed by quantitative real-time PCR, and proteins were assessed by immunoblotting and semiquantitative immunofluorescence microscopy. Effects of H2S on rat UA relaxation were determined by wire myography ex vivo. H2S production was greater in NP pPRM and P than NP sPRM UAs and inhibited by the specific CBS but not CSE inhibitor. CBS but not CSE mRNA and protein were greater in NP pPRM and P than NP sPRM UAs. CBS protein was localized to endothelium and smooth muscle and its levels were in a quantitative order of P >NP UAs of pPRM>sPRM. CSE protein was localized in UA endothelium and smooth muscle with no difference among groups. A H2S donor relaxed P > NP UAs but not mesentery artery. Thus, human UA H2S production is augmented with endothelium and smooth muscle CBS upregulation, contributing to UA vasodilation in the estrogen-dominant physiological states in the proliferative phase of the menstrual cycle and pregnancy.

Dimethylsulfide (DMS), a climatically important gas generated by dimethylsulfoniopropionate (DMSP) degradation, plays an important role in the global sulfur cycle and affects the global climate. Marine bacteria are the primary mediators of DMSP degradation and DMS production. Here, we present the complete genome sequence of Rhodococcus sp. NJ-530, isolated from Antarctic sea ice, which utilizes DMSP as a sole carbon and energy source, degrading DMSP into DMS. The genome of strain NJ-530 consists of 7371 protein-coding sequences (CDSs) with 54 tRNA genes and 15 rRNA operons as 5S-16S-23S rRNA. The strain has one circular chromosome of 6,408,544 bp with 6331 CDSs and 62.41% GC content. Genomic annotation revealed that Rhodococcus sp. NJ-530 may have a DMSP cleavage gene cluster, including dddD, dddB and dddC, suggesting the existence of the DddD-type DMSP cleavage pathway. The complete genome sequence of Rhodococcus sp. NJ-530 will provide useful information for better understanding of the molecular mechanism underlying marine DMSP degradation and Antarctic DMS production.

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The spatial and temporal distribution, congener profiles and ecological risk of phthalic acid esters (PAEs) were investigated in the seawater and sediment samples from the East China Sea in spring and autumn. The average concentrations of ΣPAEs in water samples were 3.16 ± 2.16 μg L−1 in autumn and 1.63 ± 1.20 μg L−1 in spring. The ΣPAEs in sediment was much higher than that in seawater, with an average value of 7.36 ± 6.70 mg kg−1 (dw). PAEs levels in the sea-surface microlayer (SML) in spring were 3.61 ± 3.36 μg L−1, indicating that the PAEs were noticeably concentrated in the SML, with an average enrichment factor of 2.10. Among the 16 PAE congeners, di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and di(2-ethylhexyl) phthalate (DEHP) were the preponderant PAEs in both sediment and seawater samples. Additionally, PAE concentrations in autumn were higher than those in spring, and this difference resulted mainly from the terrigenous input and marine transportation. The horizontal distributions of PAEs showed an opposite distribution pattern to salinity and temperature, a pattern which might be influenced by the inputs of fresh water. The vertical distributions of ΣPAEs were characterized by high concentrations in the surface waters, with a slight decrease with depth, and then an increase close to the seabed. The results of ecological risk in the water-phase showed that the level of potential risk followed the order of DEHP > DiBP and DnBP > DMP and DEP, which posed a high (DEHP), medium (DiBP and DnBP) and low (DMP and DEP) risk to the sensitive organisms, respectively. For the sediment-phase, DiBP and DnBP represented a high risk to the sensitive organisms, whereas DMP, DEP and DEHP had only a low risk.

The sorption behavior of phosphorus onto sediment was investigated with the addition of BC derived from incomplete biomass combustion (PC). The sorption kinetic curves of phosphorus onto PC and sediment could be described by a two-compartment first order equation, and the sorption isotherms fit the Freundlich model well. With increasing amounts of PC added, the sorption capacity increased while the HI did not change much. The distribution of phosphorus forms showed that CaP (ACa-P plus DAP) constituted the highest fraction in the sediment samples. Throughout the sorption process, CaP and OP changed very little, but the Ex-P and FeP increased obviously, and the presence of PC made this increase more significantly. The high specific area and the presence of iron and aluminum, as well as the modification of the sediments surface properties, make the addition of PC be favorable for the sorption of phosphorus onto sediments.

Amino acids (AAs) and amino sugars (ASs), compounds ubiquitous to living organisms, can provide information regarding degradation states and bacterial contributions to sedimentary organic matter (SOM). However, very few studies have utilized the combination of AAs and ASs as a proxy to assess the influence of bacterial degradation on SOM in the Yellow Sea (YS). In this study, surface sediments from the YS were analyzed for AAs, ASs, total organic carbon (TOC), total nitrogen (TN), stable carbon isotope (δ13C), and grain size. The concentrations of AAs and ASs ranged from 3.29 to 26.65 μmol g−1 and from 0.50 to 9.11 μmol g−1, respectively, and together contributed 13.1% to TOC and 27.5% to TN. The concentrations of AAs and ASs were both positively correlated with the relative abundance of clay (

Marine-derived reactive gases constitute a substantial fraction of volatile organic compounds and directly impact atmospheric chemistry and the global climate. Light alkene emissions from marginal seas are limited, and their contribution to atmospheric concentrations is likely underestimated. We surveyed oceanic emissions of ethylene, propylene, and isoprene, as well as their potential controlling factors in the marginal seas of China during the cruises in 2014-2015. Significant temporal-spatial variations in ethylene, propylene, and isoprene concentrations were observed, with the highest occurring in summer near the coastal regions. Isoprene concentrations were primarily controlled by phytoplankton biomass (i.e., Chl-a) in coastal regions, while the elevated concentrations of ethylene and propylene were attributed to photochemical reactions with the high levels of dissolved organic matter (DOM). Additionally, the vertical distributions of ethylene and propylene mirrored light penetration, with exponential decrease in concentrations with depth. However, there were high values of ethylene and propylene observed at deep chlorophyll maximum, suggesting the existence of non-photochemical production pathways, most likely biological origin. Emissions of ethylene, propylene, and isoprene from the marginal seas of China were estimated to be 0.022, 0.024, and 0.011 Tg C yr-1, respectively, indicating they are important contributors to global non-methane hydrocarbons. Due to the scarcity of alkene emission data for marginal seas, current global emissions have been underestimated to some extent. It is essential to incorporate the contributions from marginal seas to accurately estimate alkene budgets on global scales.

A practical and efficient H/D exchange method for selective deuteration of terminal alkynes was disclosed. The reaction was simply performed with CF3COOAg as catalyst at room temperature, affording products with high level of deuterium incorporation. The excellent site-selectivity and promising functional group tolerance of this protocol enabled deuteration of pharmaceuticals and nature product derivatives.

t-Bu3P-coordinated 2-phenylaniline-based palladacycle complex (1) as the unique source of Pd(0)/t-Bu3P to form efficient initiators with ArBr for controlled Suzuki cross-coupling polymerizations of AB-type monomers was described. The in situ generated initiators were demonstrated to be robust initiator systems for controlled Suzuki cross-coupling polymerization, affording polymers with unprecedentedly narrow PDIs and well-controlled functional end groups. 31P NMR study suggested that the fast and efficient generation of ArPd(t-Bu3P)Br complexes from precatalyst 1 and ArBr might be the reason for better control of polymerization with precatalyst 1/ArBr as initiators. Our study provided a family of unprecedented, highly efficient initiators for controlled Suzuki cross-coupling polymerizations and a direct route to access conjugated polymers with a variety of heterobisfunctional chain end groups.

Temporal distributions of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) were studied in the southern Yellow Sea (SYS) during April and September 2010. The mean concentrations (range) of DMS, dissolved and particulate DMSP (DMSPd and DMSPp) in the surface waters in spring are 1.69 (0.48-4.92), 3.18 (0.68-6.75) and 15.81 (2.82-52.33) nmol/L, respectively, and those in autumn are 2.80 (1.33-5.10), 5.45 (2.19-11.30) and 30.63 (6.24-137.87) nmol/L. On the whole, the distributions of DMS and DMSP in spring are completely different from those in autumn. In the central part of the SYS, the concentrations of DMS and DMSP in spring are obviously higher than those in autumn, but the opposite situation is found on the south of 34 degrees N, which can be attributed to the differences in nutrients and phytoplankton biomass and composition between spring and autumn. Besides, the seasonal variations of water column stability and the Changjiang diluted water also have significant impact on the distributions of DMS and DMSP in spring and autumn on the south of 34 degrees N. DMS and DMSPp concentrations coincide well with chlorophyll a (Chl a) levels in the spring cruise, suggesting that phytoplankton biomass may play an important role in controlling the distributions of DMS and DMSPp in the study area. Annual DMS emission rates range from 0.015 to 0.033 Tg/a (calculated by S), respectively, using the equations of Liss and Merlivat (1986) and Wanninkhof (1992). This result implies a significant relative contribution of the SYS to the global oceanic DMS fluxes.

The biogeochemical cycle of biogenic dimethylated sulfur compounds in oceans has received significant attention because of their critical role in the global climatic and atmospheric processes. The behavior of biogenic dimethylated sulfur compounds including dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) was measured in the waters of the Changjiang River Estuary and the coastal East China Sea during two cruises from 7 to 20 March 2016 and from 4 to 16 July 2016. The concentrations of DMS, particulate DMSP (DMSPp), dissolved DMSP (DMSPd), particulate DMSO (DMSOp) and dissolved DMSO (DMSOd) in the study area showed significant spatial and seasonal variation, with higher values in summer. DMS displayed significant relationships with DMSPp, DMSPd and DMSOp, and the dimethylated sulfur compound distributions showed similar patterns with that of chlorophyll a (Chl-a). The seasonal variation in DMSOd was inconspicuous compared to other sulfur compounds and its concentration inside the estuary was relatively high, suggesting an impact by anthropogenic activities and riverine inputs. Phytoplankton biomass and water mass mixing (upwelling and the Changjiang diluted water) played an important role in controlling the distributions of dimethylated sulfur compounds in the Changjiang River Estuary and the coastal East China Sea. The mean sea-to-air fluxes of DMS in this study area were 3.21 and 20.73 μmol m−2 d−1 in spring and summer, respectively. The study area was a net source for atmospheric DMS.

A mesocosm experiment was conducted in Wuyuan Bay (Xiamen), China to investigate the effects of elevated pCO2 on phytoplankton species and production of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) as well as four halocarbon compounds (CHBrCl2, CH3Br, CH2Br2, and CH3I). Over a period of 5 weeks, P. tricornutum outcompeted T. weissflogii and E. huxleyi, comprising more than 99 % of the final biomass. During the logarithmic growth phase (phase I), DMS concentrations in high pCO2 mesocosms (1000 µatm) were 28.2 % lower than those in low pCO2 mesocosms (400 µatm). Elevated pCO2 led to a delay in DMSP-consuming bacteria attached to T. weissflogii and P. tricornutum and finally resulted in the delay of DMS concentration in the HC treatment. Unlike DMS, the elevated pCO2 did not affect DMSP production ability of T. weissflogii or P. tricornutum throughout the 5 week culture. A positive relationship was detected between CH3I and T. weissflogii and P. tricornutum during the experiment, and there was a 40.2 % reduction in mean CH3I concentrations in the HC mesocosms. CHBrCl2, CH3Br, and CH2Br2 concentrations did not increase with elevated chlorophyll a (Chl a) concentrations compared with DMS(P) and CH3I, and there were no major peak in the HC or LC mesocosms. In addition, no effect of elevated pCO2 was identified for any of the three bromocarbons.

Ocean acidification (OA) affects marine primary productivity and community structure, and therefore may influence the biogeochemical cycles of volatile biogenic dimethyl sulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) and photochemical oxidation product dimethyl sulfoxide (DMSO). A 23-day incubation experiment on board was conducted to investigate the short-term response of biogenic sulfur compounds production and cycling to OA in the Changjiang River Estuary and further understand its effects on biogenic sulfur compounds. Result showed that phytoplankton abundance and species presented remarkable differences under three different pH levels in the late stage of the experiment. A significant reduction in chlorophyll a (Chl-a), DMS, particulate DMSP (DMSPp), and dissolved DMSO (DMSOd) concentrations was identified under high CO2 levels. Moreover, minimal change was observed in the production of dissolved DMSP (DMSPd) and particulate DMSO (DMSOp) among treatments. The ratios of DMS, total DMSP (DMSPt), and total DMSO (DMSOt) to Chl-a were also not affected by a change in pH. In addition, DMS and DMSOd were highly related to mean bacterial abundance under three pH levels. Additional incubation experiments on light and temperature showed that the influence of pH on productions of dimethylated sulfur compounds also depended on solar radiation and temperature conditions. DMS photodegradation rate increased with decreasing pH under full-spectrum natural light and UVB light. Thus, OA may lead to decreasing DMS concentrations in the surface seawater. Light and temperature conditions also play an important role in the production and cycling of biogenic sulfur compounds.

The total suspended particulate (TSP) samples over the Bohai Sea and the Yellow Sea were collected during two cruises in spring and autumn in 2012. Concentrations of water-soluble ions {Na+, K+, NH4+, Mg2+, Ca2+, Cl−, NO3 −, SO42−, and CH3SO3 − [methanesulfonic acid (MSA)]} and trace metals (Al, Pb, Zn, Cd, Cu, and V) were measured. Mass concentrations of TSP samples ranged from 65.2 to 136 μg m−3 in spring and from 15.9 to 70.3 μg m−3 in autumn, with average values of 100 ± 22.4 and 40.2 ± 17.8 μg m−3, respectively. The aerosol was acidic throughout the sampling periods according to calculation of equivalent concentrations of the cations (NH4+, nss-Ca2+, and nss-K+) and anions (nss-SO42− and NO3 −). Correlation analysis and enrichment factors revealed that the aerosol composition in the coastal marine atmosphere had a feature of a mixture of air masses: that is, crustal, marine, and anthropogenic emissions. Trace metals were enriched by a wide range of 1–103, and enrichment factors for crustal source (EFc) were relatively higher in spring. Species like Cd, Zn, and Pb had an overwhelming contribution from anthropogenic sources. In addition, the concentrations of MSA varied from 0.0075 to 0.17 and from 0.0019 to 0.018 μg m−3 during the spring and autumn cruises, respectively, with means of 0.061 and 0.012 μg m−3, respectively. Based on the observed MSA and nss-SO42− concentrations in spring and autumn, the relative biogenic sulfur contributions to nss-SO42− were estimated to be 8.0% and 3.5% on average, respectively, implying that anthropogenic sources had a dominant contribution to the sulfur budget over the observational area.

Thinner powder layers are beneficial to three-dimensional printing (3DP) parts in many aspects, such as accuracy, surface quality and densification. However, counter-rolling (CR) layering (belonging to dry-powder layering method) and slurry-based layering, which are both conventional layering methods, either cannot achieve ultra-thin layering due to the considerable layering defects (including the cavity defect and part-shifting defect) or must involve complicated processes. Therefore, to keep the convenience of dry-powder layering and avoid the excessive layering defects, a feasibility study of the double-smoothing (DS) method for ultra-thin layering was conducted on a self-developed 3DP machine in this work. Furthermore, with optical monitoring, layering defects were first investigated experimentally. It is proved that DS layering method is capable of dispensing dry powder into intact ultra-thin (55 μm) layers: the cavity defects were well restricted, the layer-location deviations of the printed green parts were within 100 μm per 218 layers, the green densities exceeded 70%, and the uniform structures within the printed specimens were also realized. Combining a modified Mohr–Coulomb failure theory (Jenike yield theory) and the solution of in-powder stress fields induced during powder layering, a theoretical framework was established to primarily interpret the restriction of layering defects benefiting from the DS layering, whereby this theoretical framework as a reference tool for future 3DP design works was also implied.

Estrogens dramatically dilate numerous vascular beds with the greatest response in the uterus. Endogenous hydrogen sulfide (H2S) is a potent vasodilator and proangiogenic second messenger, which is synthesized from L-cysteine by cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE). We hypothesized that estrogen replacement therapy (ERT) selectively stimulates H2S biosynthesis in uterine artery (UA) and other systemic arteries. Intact and endothelium-denuded UA, mesenteric artery (MA), and carotid artery (CA) were obtained from ovariectomized nonpregnant ewes (n = 5/group) receiving vehicle or estradiol-17β replacement therapy (ERT). Total RNA and protein were extracted for measuring CBS and CSE, and H2S production was determined by the methylene blue assay. Paraffin-embedded UA rings were used to localize CBS and CSE proteins by immunofluorescence microscopy. ERT significantly stimulated CBS mRNA and protein without altering CSE mRNA or protein in intact and denuded UA. Quantitative immunofluorescence microscopic analyses showed CBS and CSE protein localization in endothelium and smooth muscle and confirmed that ERT stimulated CBS but not CSE protein expression in UA endothelium and smooth muscle. ERT also stimulated CBS, but not CSE, mRNA and protein expression in intact and denuded MA but not CA in ovariectomized ewes. Concomitantly, ERT stimulated UA and MA but not CA H2S production. ERT-stimulated UA H2S production was completely blocked by a specific CBS but not CSE inhibitor. Thus, ERT selectively stimulates UA and MA but not CA H2S biosynthesis by specifically up-regulating CBS expression, implicating a role of H2S in estrogen-induced vasodilation and postmenopausal women's health.

The distributions of dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) in surface water of the Yellow Sea and the Bohai Sea were studied during June 2011. The mean concentrations and ranges of DMS, dissolved DMSP (DMSPd), and particulate DMSP (DMSPp) in surface waters were 6.85 (1.60-12.36), 7.25 (2.28-19.05) and 61.87 (6.28-224.01) nmol/L, respectively. There were strong correlations between DMSPp and chlorophyll a in the Bohai Sea and the North Yellow Sea, respectively, and concentrations of DMS and DMSP were high, with a relatively high proportion of dinoflagellates, in the region of the South Yellow Sea Cold Water Mass. Results show that phytoplankton biomass and species composition were important factors that controlled the distribution of DMS and DMSP. Complex environmental factors, including nutrients, transparency, and terrestrial runoff, might also influence the variability in DMS and DMSP. Biological production and consumption rates of DMS in the Bohai Sea were higher than those in the Yellow Sea. DMS production rates were closely correlated with DMSPd concentrations. DMS and DMSP exhibited obvious diel variations, with high concentrations occurring in the late afternoon (16:00-19:00) and low concentrations occurring during the night, implying that the intensity of solar radiation had a significant influence on these variations. Size distributions of chlorophyll a and DMSPp were also investigated and large nanoplankton (5-20 mu m), mainly diatoms, contributed significantly to chlorophyll a and DMSPp at most stations. The average sea-to-air flux of DMS in the study area was estimated to be 11.07 mu mol/(m(2)center dot d) during the summer.

Gas chromatography with mass spectrum detector (GC-MSD) coupled with purge-and-trap system was developed to analyze the concentration of isoprene in natural waters. The experimental conditions were optimized, including purge gas flow rate (50 mL min −1 ), purge time (15 min), capillary column (Rt-Alumina BOND/KCl) and its appropriate temperature programming. The precision was less than 4% ( n = 6), the detection limit was 0.5 pM, and the recovery was 91%–102%. The analytical results of preservative experiments showed that no obvious variation was observed in the concentrations of isoprene within 60 days under the preservation conditions. The concentrations of isoprene measured with the method ranged from 60.8 pM to 278.7 pM in the Jiaozhou Bay and its adjacent river estuaries, and from 44.7 pM to 77.2 pM in the Yellow River estuary, respectively, which were in good accord with those reported in literatures in other coastal waters. In conclusion, the analytical method meets completely the requirements of the analysis of concentration of isoprene in natural waters.

The synthesis of well-defined and functionalized conjugated polymers, which are essential in the development of efficient organic electronics, through Suzuki cross-coupling polymerizations has been a challenging task. We developed controlled Pd(0)/t-Bu3P-catalyzed Suzuki cross-coupling polymerizations of AB-type monomers via the chain-growth mechanism with a series of in situ generated ArPd(t-Bu3P)X (X = I, Br, Cl) complexes as initiators. Among them, the combinations of Pd2(dba)3/t-Bu3P/p-BrC6H4I, Pd2(dba)3/t-Bu3P/p-BrC6H4CH2OH and Pd2(dba)3/t-Bu3P/p-PhCOC6H4Br were identified as highly robust initiator systems, resulting in polymers with predictable molecular weight and narrow polydispersity (PDI~1.13-1.20). In addition, Pd2(dba)3/t-Bu3P/p-BrC6H4CH2OH and Pd2(dba)3/t-Bu3P/p-PhCOC6H4Br initiator systems afforded functional polymers with >95% fidelity. Our results paved the road to access well-defined conjugated polymers, including conjugated polymers with complex polymer architectures such as block copolymers and branch copolymers.

article i nfo Article history: Spatial distributions of biogenic sulfur compounds including dimethylsulfide (DMS), dissolved and particulate dimethylsulfoniopropionate (DMSPd and DMSPp) were investigated in the Bohai Sea (BS) and northern Yellow Sea (NYS) in November 2011. DMS and DMSPp concentrations were significantly correlated with chlorophyll a (Chl-a) in the surface water and larger nanoplankton (5-20 μm) was the most important producer of DMSPp in the study area. Silicate had statistically significant influence on the growth of phytoplankton and DMSP con- centration. The vertical profiles of DMS and DMSP were characterized by a maximum at the upper layer and the bottom concentrations were sometimes relatively higher compared with the overlying layer. The sea-to-air fluxes of DMS in the study area were estimated to be from 0.05 to 27.4 μmol m −2 d −1 ,w ith am ean of 4.21 μmol m −2 d −1 . The contribution of biogenic non-sea-salt SO4 2− (nss-SO4 2− ) to total nss-SO4 2− in the atmo- spheric aerosol over the study area varied from 0.46% to 5.49% with an average of 1.40%. Therefore, the contribu- tion of biogenic sulfur to nss-SO4 2− was not significant and anthropogenic source was dominant for atmospheric sulfate.

Since 2007, the green algal bloom occurred along the coast of Qingdao city every summer. In this study, we focused on how the carbonate system responded to the green algal bloom. Dissolved inorganic carbon (DIC), total alkalinity (TA) and pH were measured in two cruises during the green algal post-bloom period in summer 2008 in the southern Yellow Sea. Data showed that the average values of alkalinity calculated from DIC and pH were 2217 and 2241 μmol kg−1 during the first and second cruises, respectively. The alkalinity measured by Gran titration, however, was abnormal, with average values of 3333 and 3280 μmol kg−1. The abnormal measured TA values were probably due to both direct contribution of organic matter and its side reaction in determining TA using Gran titration. Another significant phenomenon was an increase of DIC and a decrease of pH after the bloom. The changes of DIC and pH during the two cruises were +87 μmol kg−1 and −0.18, respectively. Normalized DIC and TA showed that DIC was not conserved after the bloom while TA could be still conserved. In contrast to green algal bloom period, during the post-bloom period, pCO2 values were significantly raised in seawater, with average values of 596 and 981 μatm, resulting in CO2 outgassing from seawater. These results showed that carbonate system in seawater could be greatly altered by green algal bloom.

The concentrations of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and chlorophyll a (Chl-a) as well as the size distribution of particulate DMSP (DMSPp) were determined in the Yellow Sea (YS) and Bohai Sea (BS) during two cruises from 1 to 20 November 2012 and from 21 June to 11 July 2013. Besides, the biological production and consumption rates of DMS and the degradation rates of dissolved DMSP (DMSPd) were also measured. The concentrations of DMS and DMSP showed a significant seasonal variation with higher values in summer, which corresponded well with the seasonal change of Chl-a in the study area. Both DMS and DMSPp concentrations were significantly correlated with Chl-a levels, implying that phytoplankton biomass might play an important role in controlling the distributions of DMS and DMSP in the study area. The size-fractionation research showed that nanophytoplankton (5–20 μm) contributed to most of Chl-a and DMSPp in autumn and summer. The average biological production and consumption rates of DMS during summer were 13.35 and 9.80 nmol L−1 d−1, respectively, which were much higher than those during autumn. The degradation rates of DMSPd during summer ranged from 7.10 to 21.70 nmol L−1 d−1, with an average of 14.71 nmol L−1 d−1, which was nearly equal to the average biological production rate (13.35 nmol L−1 d−1) of DMS. The average sea-to-air flux of DMS in the YS and BS were 12.06 and 20.81 μmol m−2 d−1 in autumn and in summer, respectively, which were much higher than the values reported in the ocean.

Nitric oxide (NO) derived from endothelial NO synthase (eNOS) mediates vascular endothelial growth factor (VEGF)-stimulated endothelial cytoskeleton remodeling and migration; however, the underlying mechanisms are elusive. Covalent adduction of a NO moiety (NO(•)) to cysteines called S-nitrosylation (SNO) is a key NO signaling pathway. The small actin-binding protein cofilin-1 (CFL1) is essential for actin cytoskeleton remodeling. We investigated whether S-nitrosylation regulates CFL1 function and endothelial cytoskeleton remodeling and migration upon VEGF stimulation. VEGF rapidly stimulated S-nitrosylation of CFL1, which was blocked by NO Synthase inhibition and eNOS knockdown by specific eNOS-siRNA. Cys80 and Cys139 were identified as the major SNO-sites in CFL1 by LC-MS/MS. The actin severing activity of recombinant SNO-mimetic CFL1 (C80/139A DMA-CFL1), but not SNO-deficient CFL1 (C80/139S DMS-CFL1), was significantly greater than that of wild-type CFL1 (wt-CFL1). When wt-CFL1 and its mutants were overexpressed in endothelial cells, basal actin bound wt-CFL1 was undetectable but significantly increased by VEGF; basal actin bound DMA-CFL1 was readily high and basal actin bound DMS-CFL1 was detectable but low, and both were unresponsive to VEGF. Treatment with VEGF significantly increased filamentous (F-) actin and filopodium formation and cell migration in endothelial cells. Overexpression of wt-CFL1 inhibited VEGF-induced F-actin formation. Overexpression of DMA but not DMS CFL1 decreased basal but not VEGF-stimulated F-actin formation. Overexpression of DMA but not DMS CFL1 suppressed VEGF-stimulated filopodium formation and migration in endothelial cells. Thus, S-nitrosylation of CFL1 provides a novel signaling pathway post-NO biosynthesis via eNOS-derived NO for endothelial cytoskeleton remodeling and migration upon VEGF stimulation.