Long-Term Nutrient Variations in the Bohai Sea Over the Past 40 Years

As China's only continental sea, the Bohai Sea is a relatively closed environment and is vulnerable to natural changes and human activities. In this paper, the long-term variations in nutrients in the Bohai Sea and the potential influencing factors were analyzed based on historical summer and winter data from 1978 to 2016. The results showed that the concentrations of dissolved inorganic nitrogen (DIN) in the Bohai Sea continuously increased from 1990 and rapidly increased after 2002, the phosphate (PO 4 -P) concentration exhibited a decreasing trend, and the silicate (SiO 3 -Si) concentration decreased from 1978 to 1987 and increased from 1987 to 2008. The nutrient concentrations were lower in summer than in winter, and the bottom concentrations were higher than the surface concentrations in summer, whereas the vertical differences were insignificant in winter. The dominant factor determining the long-term variations in DIN were atmospheric deposition and nonpoint sources due to various human activities; the primary factors affecting PO 4 -P were riverine inputs and nonpoint sources related to natural changes and human activities; the primary factors afftecting SiO 3 -Si were riverine inputs. The N/P ratio followed the DIN variation, the Si/P ratio followed the SiO 3 -Si variation, and the Si/N ratio decreased. The nutrient ratios were lower at the bottom than at the surface and were lower in winter than in summer. The nutrient limitation changed from nitrogen limitation to phosphorus and silicon limitations. The long-term nutrient variations in the Bohai Sea have potential ecological impacts on the local red tide features

SP1 enhances Zbtb7A gene expression via direct binding to GC box in HePG2 cells

<p>Abstract</p> <p>Background</p> <p>Zbtb7A is a proto-oncogenic transcriptional regulator that plays an important role in adipogenesis, osteogenesis and oncogenesis, but little is known about the regulation of Zbtb7A gene expression which is of importance in the function uncovering of this gene.</p> <p>Finding</p> <p>Here, a 5'-flanking region of the human Zbtb7A gene was cloned and characterized. It was found that the GC box within Zbtb7A promoter is necessary for the promoter activity. Furthermore, we identified that Sp1 acts as an activator in the regulation of Zbtb7A promoter activity and the physical interaction between Sp1 and GC box is responsible for the activation of Zbtb7A gene promoter.</p> <p>Conclusion</p> <p>Our results confirmed that Sp1 upregulates Zbtb7A gene expression via direct binding to GC box within the promoter.</p

Bursting patterns with complex structures in a parametrically and externally excited Jerk circuit system

This paper aims to report complex bursting patterns in a parametrically and externally excited Jerk circuit system. Typically, the common compound bursting with two clusters in each period can be observed in this system. By the fast-slow analysis, we find that the active states related to this type of bursting are created by supercritical Hopf bifurcations. Interestingly, with the increase of parametric excitation amplitude, the common bursting pattern evolves into the ones that display complex structures. We show that the parametric excitation amplitude plays a vital role in influencing the dynamical behaviors, which is apparent from the two-parameters analysis. Then, a rich variety of dynamical phenomena including period-doubling and inverse period-doubling cascades in orbits of period 2, 4, and 8 can be observed with the increase of parametric excitation amplitude, thereby leading to complex bursting patterns with multiple-periodically active states. Besides, as a result of the period-doubling cascades, chaotic attractors are eventually discovered, which can be corroborated by the maximal Lyapunov exponent. In particular, periodic windows with period-doubling and inverse period-doubling cascades also emerge in the chaotic region when the parametric excitation amplitude increases to higher values. These give rise to the complex bursting patterns with chaotically active states. Based on this, two types of bursting patterns with complex structures, i.e., bursting patterns with multiple-periodically active states and bursting patterns with chaotically active states are revealed. Our results enrich the routes to complex bursting and deepen the understanding of bursting patterns with complex structures

Research on the process and mechanism of preparing titanium-rich materials from complex ilmenite

A new process for the development and utilization of titanium-iron sand ore from Yunnan province is proposed. We provide a detailed analysis of the chemical composition and mineral structure of the raw material, and describe a pretreatment involving low-temperature oxidation and reduction, hydrofluoric acidolysis, and hydrochloric acid leaching to remove impurities and generate titanium-rich materials. Hydrofluoric acid was used to break down the complex titanite, silica-titanium, and calcium-titanium mixture in the starting mineral into simple oxides. The results have indicated that the thermal reduction process should not be conducted at elevated temperatures. Optimal process conditions are established for the leaching process: leaching temperature of 80 °C; leaching time of 240 min; hydrofluoric acid concentration of 3%; liquid–solid ratio of 6 m l/g. Under these conditions, the extent of TFe leaching reached 96%, while the leaching of Ca and Mg reached 94%. The TiO _2 grade of the final titanium-rich material was 89.95%, with a CaO content of 0.39%, a MgO content of 0.15%, and a TFe content of 7.5%. This material can serve as raw material for subsequent chlorination

Comparison of growth of photosynthetic bacteria in axenic cultures and in co-cultures

The growth of photosynthetic bacteria (PSB) in axenic and co-cultures was studied. The abundance of PSB co-cultured with PSB strains or with heterotrophic bacteria strains was higher than that in axenic culture. The study of the interaction between PSB and heterotrophic bacteria strains revealed the relationship of synergism and/or commensalism

Antiproliferative activities of the second-generation antipsychotic drug sertindole against breast cancers with a potential application for treatment of breast-to-brain metastases

Abstract Epidemiological observations have shown that schizophrenia patients after long-term drug treatment exhibited reduced tumor incidences. The potential anticancer effects of antipsychotic drugs are subsequently demonstrated. These drugs are of great interest as agents against untreatable brain metastases because of their ability to traverse the blood-brain barrier (BBB). Most drugs tested thus far are the first-generation antipsychotics (FGAs). But their clinical application may be limited due to high risks of deaths in elderly patients. There is an urgent need to find additional BBB-traversing anticancer agents with lower risks of deaths. In this work, we investigated antitumor activities of eight second-generation-antipsychotic (SGA) drugs, since they exhibit lower mortality rates than FGAs. We discovered that sertindole showed broad antiproliferative activities against seven cancer types including 29 cell-lines and exhibited potent effects toward breast cancer cell-lines, with half maximal concentration to inhibit proliferation by 50% (IC50) as low as 800 nM. We further found that sertindole caused cell death through autophagy-associated apoptosis and its directly-binding inhibition of 5-HT6 involved in this process. In xenotransplant mice, sertindole administration approaching maximal therapeutic dose attenuated breast-tumor growth by 22.7%. Therefore, our study reveals promising anticancer potentials of sertindole against breast cancers, with probable applications for breast-to-brain metastases

Development of a GFP expression vector for Cucurbit chlorotic yellows virus

Abstract Background Cucurbit chlorotic yellows virus (CCYV), a bipartite crinivirus, causes chlorotic leaf spots and yellowing symptoms on cucurbit leaves. We previously developed an infectious clone of CCYV. Limited work has been conducted on the construction of a crinivirus green fluorescence protein (GFP) expression vector to date. Finding We constructed a CCYV GFP expression vector using the “add a gene” strategy based on CCYV RNA2 cDNA constrcut. Three resultant clones, pCCYVGFPSGC, pCCYVGFPCGC, and pCCYVGFPCGS, were constructed with different promoters used to initiate GFP and CP expression. At 25 dpi GFP fluorescence was detectable not only in leaf veins but also in the surrounding cells. pCCYVGFPCGC-infected cucumber leaves exhibited cell spread at 25 dpi, whereas pCCYVGFPSGC and pCCYVGFPCGS were mainly found in single cells. Further observation of pCCYVGFPCGC GFP expression at 30 dpi, 40 dpi, and 50 dpi showed phloem-limited localization in the systemic leaves. Conclusions We developed of a CCYV GFP expression vector that will be useful for further study of CCYV movement in cucurbits