Comparison of nutrients status in Liaodong Bay and Northern Yellow Sea, China: Controlling factors and nutrient budgets.

Under the dual stress of global warming and human interaction, Liaodong Bay (LDB) and northern Yellow Sea (NYS) are undergoing significant ecological changes. Little is known about the driving nutrients characteristics supporting fishery resource output in these areas. We carried out three field observations in 2019 to investigate nutrient status. Results showed that dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and dissolved silica (DSi) concentrations changed seasonally, with lowest values in spring, and highest values in autumn. High DIN, DIP, and DSi concentrations were detected in LDB and NYS's estuary areas. The Yellow Sea Cold Water Mass plays a role in the distribution and seasonal variation of nutrients. Exchanges across the sediment-water interface, SFGD, atmospheric deposition, and the adjacent sea input dominated DIN dynamics of these areas. DIP primarily came from the adjacent sea input and DSi mainly originated from sediment release and the adjacent sea input. NYS seawater invasion accounted for 13.8% of DIN, 63.4% of DIP, and 35.1% of DSi in LDB. These results provide new insights to better facilitate the formulation of nitrogen and phosphorus reduction and control policies in these marginal seas.

Response of microalgae size-class structure to nutrients differences in northern Yellow Sea, China.

Marine phytoplankton size-class structure affects ecological functions and shellfish culture. We use high-throughput sequencing and size-fractioned grading techniques to identify and analyze responses of phytoplankton differences in environmental variables at Donggang, northern Yellow Sea (high inorganic nitrogen (DIN)) and Changhai (low DIN) for 2021. The main environmental variables that correlate with differences in the proportional contributions of pico-, nano-, and microphytoplankton to the total phytoplankton community are inorganic phosphorus (DIP), nitrite to inorganic nitrogen ratio (NO2/dissolved inorganic nitrogen (DIN)), and ammonia nitrogen to inorganic nitrogen ratio (NH4/DIN), respectively. DIN, which contributes most to environmental differences, mainly positively correlates with changes in picophytoplankton biomass in high DIN waters. Nitrite (NO2) correlates mostly with changes in the proportional contribution of microphytoplankton in high DIN waters and nanophytoplankton in low DIN waters, and negatively correlates with changes in the biomass and proportional representation of microphytoplankton in low DIN waters. For near-shore phosphorus-limited waters, an increase in DIN may increase total microalgal biomass, but proportions of microphytoplankton may not increase; for high DIN waters, an increase in DIP may increase proportions of microphytoplankton, while for low DIN waters, an increase in DIP may preferentially increase proportions of picophytoplankton and nanophytoplankton. Picophytoplankton contributed little to the growth of two commercially cultured filter-feeding shellfish, Ruditapes philippinarum and Mizuhopecten yessoensis.

Sources and spatiotemporal variations of nitrogen and phosphorus in Liaodong Bay, China.

Excessive discharge of N and P pollutants results in deterioration of marine environment quality and reduction of sustainability and safety of marine ecology. Spatiotemporal variations characteristics and sources of N and P pollutants were determined based on the long-term monitoring data in Liaodong Bay. Results indicated that an evident spatiotemporal variation was investigated for nutrients. The highest concentrations of NH3-N, NO2-N, NO3-N and PO4-P were in spring (25.32 µg/L), summer (20.67 µg/L) and autumn (222.07 µg/L, 11.08 µg/L), respectively. The hot-spots of pollutants were mainly concentrated in estuarine and aquaculture areas. The hot spot of PO4-P gradually extended to the middle of Liaodong Bay in autumn. In addition, pollution sources in each marine functional zone were different, the main pollution source was aquaculture wastewater, river input, domestic sewage. This study provided reasonable suggestions for effectively reducing N and P pollution in Liaodong Bay, and elsewhere.

Oral Pycnogenol® Intake Benefits the Skin in Urban Chinese Outdoor Workers: A Randomized, Placebo-Controlled, Double-Blind, and Crossover Intervention Study.

BACKGROUND: Oral supplementation with a standardized extract from the bark of the French pine (Pycnogenol®) has been reported to benefit the skin. It might thus represent an easy-to-use strategy to improve the skin health of individuals who are exposed to considerable environmental stress in large urban areas. OBJECTIVE: We investigated if oral intake of Pycnogenol® can benefit the skin of Han Chinese working outdoors in Beijing, China. METHODS: In a monocentre, double-blind, randomized, placebo-controlled, and crossover study, the effects of Pycnogenol® intake (2 × 50 mg/day for a total of 12 weeks) on a variety of skin physiological parameters was studied in Chinese subjects (n = 76), from spring to autumn, who were working outdoors in Beijing, China. RESULTS: During the intervention period, study subjects were constantly exposed to increased levels of particulate matter (PM)2.5 as well as seasonal changes in humidity and temperature. Despite this environmental stress, Pycnogenol® intake prevented (i) a decrease in the skin hydration, (ii) transepidermal water loss (TEWL), and (iii) skin darkening during the dry autumn season. In addition, Pycnogenol® intake improved (iv) viscoelastic skin properties such as gross elasticity and elastic recovery irrespective of the season. These beneficial effects were not observed if the same subjects were supplemented with placebo. CONCLUSION: Oral intake of Pycnogenol® benefits the skin in Han Chinese, who are working outdoors under considerable environmental stress.

Protective effect of curcumin against irinotecan­induced intestinal mucosal injury via attenuation of NF­κB activation, oxidative stress and endoplasmic reticulum stress.

Irinotecan (CPT­11) is a DNA topoisomerase I inhibitor which is widely used in clinical chemotherapy, particularly for colorectal cancer treatment. However, late­onset diarrhea is one of the severe side­effects of this drug and this restricts its clinical application. The present study aimed to investigate the protective effects of curcumin treatment on CPT­11­induced intestinal mucosal injury both in vitro and in vivo and to elucidate the related mechanisms involved in these effects. For this purpose, mice were intraperitoneally injected with CPT­11 (75 mg/kg) for 4 days to establish a model of late­onset diarrhea. Curcumin (100 mg/kg) was intragastrically administered 8 days before the injection of CPT­11. Injury to small intestinal tissues was examined by H&E staining. The protein expression of prolyl 4­hydroxylase subunit beta (P4HB) and peroxiredoxin 4 (PRDX4) was detected by immunohistochemistry, as well as western blot analysis. IEC­6 cell viability was detected by MTT assay. Flow cytometry was performed to examine the cell apoptotic rate, mitochondrial membrane potential and reactive oxygen species (ROS) generation. Immunofluorescence was used to observe the localization of nuclear factor (NF)­κB. The levels of cleaved caspase­3, glucose­regulated protein, 78 kDa (GRP78), P4HB, PRDX4 and CHOP were detected by western blot analysis. The results revealed that in vivo, curcumin effectively attenuated the symptoms of diarrhea and abnormal intestinal mucosa structure induced by CPT­11 in nude mice. Treatment with curcumin also increased the expression of P4HB and PRDX4 in the tissue of the small intestine. In vitro, curcumin, exhibited little cytotoxicity when used at concentrations <2.5 µg/ml for 24 h in IEC­6 cells. At this concentration, curcumin also improved cell morphology, inhibited apoptosis, maintained mitochondrial membrane potential and reduced the elevated levels of ROS induced by CPT­11 (20 µg/ml). Furthermore, curcumin abolished NF­κB signal transduction and protected the cells from CPT­11­induced apoptosis by upregulating the expression of molecular chaperones, such as GRP78, P4HB and PRDX4, and suppressing the levels of the apoptosis­related proteins, CHOP and cleaved caspase­3. On the whole, our data indicate that curcumin exerted protective effects against CPT­11­induced intestinal mucosa injury. The protective effects of curcumin are mediated by inhibiting the activation of NF­κB, and suppressing oxidative stress and endoplasmic reticulum stress.