Two superconducting states with broken time-reversal symmetry in FeSe1-xSx.

Iron-chalcogenide superconductors FeSe1-xSx possess unique electronic properties such as nonmagnetic nematic order and its quantum critical point. The nature of superconductivity with such nematicity is important for understanding the mechanism of unconventional superconductivity. A recent theory suggested the possible emergence of a fundamentally new class of superconductivity with the so-called Bogoliubov Fermi surfaces (BFSs) in this system. However, such an ultranodal pair state requires broken time-reversal symmetry (TRS) in the superconducting state, which has not been observed experimentally. Here, we report muon spin relaxation (µSR) measurements in FeSe1-xSx superconductors for 0 ≤ x ≤ 0.22 covering both orthorhombic (nematic) and tetragonal phases. We find that the zero-field muon relaxation rate is enhanced below the superconducting transition temperature Tc for all compositions, indicating that the superconducting state breaks TRS both in the nematic and tetragonal phases. Moreover, the transverse-field µSR measurements reveal that the superfluid density shows an unexpected and substantial reduction in the tetragonal phase (x > 0.17). This implies that a significant fraction of electrons remain unpaired in the zero-temperature limit, which cannot be explained by the known unconventional superconducting states with point or line nodes. The TRS breaking and the suppressed superfluid density in the tetragonal phase, together with the reported enhanced zero-energy excitations, are consistent with the ultranodal pair state with BFSs. The present results reveal two different superconducting states with broken TRS separated by the nematic critical point in FeSe1-xSx, which calls for the theory of microscopic origins that account for the relation between nematicity and superconductivity.

Effects of suspended particular matters, excess PO43-, and salinity on phosphorus speciation in coastal river sediments.

Phosphorus (P) is an essential biogenic element in aquatic ecosystem, and its speciation in sediment may influence the water quality. The composition of P in suspended particular matters (SPM) and sediments were analyzed. Metal ions bonding PO43- and chelating organic P (OP) were explored by Visual MINTEQ simulation and infrared spectroscopy. Inorganic P (IP) mainly comprises orthophosphate and pyrophosphate in SPM. OP mainly includes α-glycerol phosphate, ß-Gly, monophosphate, and mononucleotides from aquatic plants in SPM. Cyclotella, Nitzschia, Amphiprore, and terrestrial C3 plants are the main source of aquatic plants in JH, while they are from Oscillatoria and Merismopedia in JL. These aquatic plants directly determine whether OP or IP is taken to surface sediments during the setting of SPM. The bonding between PO43- and Ca is more preferential than Al and Fe, so the excess PO43- makes Ca compounds bonding IP (Ca-IP) and Al/Fe/Mn (hydr) oxides associated IP (Al/Fe/Mn-IP) dominant, but limited PO43- preferentially contributes more Ca-IP. Metal ions in saline water can firmly cheat with OP via P-OH and/or P=O groups to promote the burial of OP.

Redox-dependent phosphorus burial and regeneration in an offshore sulfidic sediment core in North Yellow Sea, China.

Phosphorus (P) pollution can trigger severe marine eutrophication, which further leads to harmful algal blooms, and a deterioration of sea water quality. The P burial and regeneration in offshore sediments can directly affect the eutrophication levels of estuarine and coastal ecosystems. Although many researches on redox-dependent P burial and regeneration were studied, such process in the presence of silicate is still poorly understood, and the effects of pyrite formation on organic P (OP) burial and regeneration also remain unclear. In this study, a sulfidic sediment core was collected in the offshore of an estuary in the north Yellow Sea, China. Results indicated that indigenous biological input was found to be the primary source of organic matter in upper sediments. The regenerated P under reducing conditions was dominated by labile FeP and OP. The PO43- released from FeP and OP that could be captured by Al/Fe/Mn (oxyhydr) oxides in surface sediments and Ca minerals in deep sediments. CaP, AlP, unreactive Al/Fe-Si-P and some stable metal chelated OP were the main burial P fractions. Sulfate reduction and formation of insoluble metal sulfides including the pyrite promoted OP decomposition by anaerobic decomposition, removing metal ions from the "metal-OP" chelates and restoring the phosphatase activity.

Effects of macro metals on alkaline phosphatase activity under conditions of sulfide accumulation.

Alkaline phosphatase (AP) is commonly found in aquatic ecosystems as an extracellular enzyme closely related to the biogeochemical cycling of phosphorus. Although the AP activity (APA) is conventionally thought to be a main response to PO43- starvation, significant effects of macro metal elements (Al, Fe, and Ca) and S on the APA were found in this study. The APA was reduced by Al primarily through the adsorption of the enzyme onto AlOOH colloids. Fe2+ inhibited the APA via a mechanism involving free radical oxidation. The main mechanism by which Ca2+ inhibited the APA was by competing with Mg2+ and Zn2+ for the active sites of the enzyme. Excessive S2- could reduce the APA by removing Zn2+ from the active sites of the enzyme. The inhibition of APA could be reversed if some metal ions (e.g., Fe2+) were precipitated by S2- under reducing conditions. Therefore, in anaerobic ecosystems, the effects of macro metals on APA under conditions of sulfide accumulation may have innovative implications for phosphorus management.

The biogeochemical characteristics of phosphorus in coastal sediments under high salinity and dredging conditions.

The geochemistry of phosphorus (P) can usually be related to prevailing environmental conditions. To investigate sedimentary P cycling mechanism and biogeochemical characteristics under high salinity and dredging conditions in polluted coastal sediments, thirty-three surface sediment samples were collected from the Jiehe River (JH), Jiaolai River (JL) and their estuarine and offshore areas in the Bohai Sea. Analyses included the Standards, Measurements and Testing method (SMT), Ivanoff organic P (OP) fractionation, and nuclear magnetic resonance (31P-NMR) of soluble P and indicated that HCl-P was the dominant fraction in sediments under high salinity stress. However, under dredging conditions in freshwater river sediments, NaOH-P was the dominant fraction. The potential activity of the OP fraction was reactive in freshwater river sediments, while it was unreactive under high salinity conditions. NaOH-P and HCl-P were found to be mainly derived from anthropogenic inputs, whereas both in-situ biological and anthropogenic inputs were important sources of the OP fractions. High salinity had the potential to increase NaOH-P content in acidic river sediments, resulting in the OP being relatively stable with a low risk level. Sediment dredging potentially increased the regeneration of P from HCl-P and OP and increased the potential activity of OP and IP. Seawater was found to induce removal of the NaOH-P and OP from offshore sediments, resulting in the regeneration of the remaining P at a low level.

In situ microbial remediation of crude oil-soaked marine sediments using zeolite carrier with a polymer coating.

Marine oil spill pollution is an important environmental problem in the world, especially crude oil-soaked marine sediments, because they are difficult to be remediated. In this study, in situ bioremediation of oil-soaked sediment was performed in the middle of the Bohai Sea. Oil-degrading bacteria were adsorbed on powdery zeolite (PZ)/granular zeolites (GZ) surfaces and then wrapped with poly-γ glutamic acid (γ-PGA). Settling column and wave flume experiments were conducted to model marine conditions and to select appropriate biological reagents. The optimal conditions were as follows: the average diameter of GZ 3 mm, mass ratio of GZ/PZ 2:1, and concentration of γ-PGA 7%. After bioremediation, over 50% of most oil-spilled pollutants n-alkanes (C12 to C27) and polycyclic aromatic hydrocarbons were degraded in 70 days. This work resulted in a successful trial of in situ bioremediation of oil-soaked marine sediments.

A novel dual-luciferase assay for anti-HIV drug screening based on the CCR5/CXCR4 promoters.

Acquired immunodeficiency syndrome (AIDS) is a serious worldwide disease caused by infection with the human immunodeficiency virus (HIV). C-C chemokine receptor 5 (CCR5) and C-X-C chemokine receptor 4 (CXCR4) are important coreceptors mediating HIV-1 cell entry. Many new anti-HIV drugs are currently in preclinical and clinical trials; however, drug development has proceeded slowly partly because of the lack of a high-throughput system to screen these drugs. Here, we describe the development of a novel dual-luciferase assay using a CCR5/CXCR4 promoter-driven firefly and Renilla luciferase vector (pGL4.10-RLUC-CCR5/CXCR4). Drugs were screened for the ability to regulate CCR5 and CXCR4 promoter activities. The CCR5 and CXCR4 promoters were inserted separately into the recombinant vector and transfected into the acute T lymphocyte leukemia cell line H9. Treatment of stable transfected cells with four traditional Chinese medicine compounds resulted in the dose-dependent inhibition of the CXCR4 and CCR5 promoter activities. The dual-luciferase reporter assay provides a rapid and direct method to screen anti-AIDS/HIV drugs.

Feasibility assessment: application of ecological floating beds for polluted tidal river remediation.

The remediation of polluted coastal rivers is a global challenge in the environmental field. The objective of this study was to investigate the remediation feasibility of a high-salinity river using water spinach (WS) and sticky rice (SR) in hydroponic floating-bed systems. In this study, the total nitrogen (TN) removal rates were 89.7, 92.3, 85.1, and 75.2% in the WS floating-bed system and 81.2 and 78.9% in the SR floating-bed system under different salinities (2-31 psu). Additionally, the total phosphorus (TP) removal rates were 94.4, 96.4, 93.5, and 75.2% in the WS floating-bed system and 75.7 and 80.0% in the SR floating-bed system under different salinities. The results indicate that WS and SR significantly contributed to the remediation of a polluted tidal river. Additionally, increased salinity suppressed the removal of ammonium and phosphate by WS and SR. The salt tolerance of WS was greater than that of SR, which indicated that WS was a more appropriate choice for treating river contamination.

Myricetin enhance chemosensitivity of 5-fluorouracil on esophageal carcinoma in vitro and in vivo.

BACKGROUND: Flavonoids are structurally heterogeneous, polyphenolic compounds present in high concentrations in fruits, vegetables, and other plant-derived foods. Currently, there is growing interest in the therapeutic applications of bioflavonoids for the treatment and prevention of diseases in humans. Myricetin is a naturally occurring flavonoid that is commonly found in tea, berries, fruits, vegetables, and medicinal herbs. Previous studies have shown that myricetin has antioxidant, anti-inflammatory and potent anticancer effects. It was interesting to investigate whether myricetin has the cooperative inhibitory effect combined with 5-fluorouracil on esophageal cancer cells. METHODS: EC9706 cells were treated with 5-fluorouracil combination with or without myricetin. Colony formation assays, CCK-8 assay and flow cytometry were used to evaluate the chemosensitization activity of myricetin combine with 5-fluorouracil on the cell growth and viability, cell proliferation and apoptosis in vitro. Western blot was engaged to detect changes of Survivin, Cyclin D, Bcl-2, Caspase-3 and P53 protein expression level, which were associated with cells proliferation and apoptosis. Nude mouse tumor xenograft model was built to assessed chemosensitization effect of myricetin combine with 5-fluorouracil in vivo. RESULTS: Compared with the 5-fluorouracil group without myricetin treatment, the groups treated with 5-fluorouracil combine with myricetin showed significantly suppressed cell survival fraction and proliferation, increased the cell apoptosis. Decreased Survivin, Cyclin D, Bcl-2, and increased Caspase-3, P53 expression level were aslo confirmed by western blot in 5-fluorouracil combine with myricetin groups in vitro. And in vivo assay, growth speed of tumor xenografts was significantly decreased in the mice treated with 5-fluorouracil + myricetin combiantion group. CONCLUSIONS: The study demonstrated both in vitro and in vivo evidence that combination of myricetin with 5-fluorouracil chemotherapy can enhance tumor chemosensitivity of esophageal cancer EC9706 cells, and myricetin could be a potential chemosensitizer for esophageal cancer therapy.

Astragalus saponins affect proliferation, invasion and apoptosis of gastric cancer BGC-823 cells.

BACKGROUND: Astragalus memebranaceus is a traditional Chinese herbal medicine used in treatment of common cold, diarrhea, fatigue, anorexia and cardiac diseases. Recently, there are growing evidences that Astragalus extract may be a potential anti-tumorigenic agent. Some research showed that the total saponins obtained from Astragalus membranaceus possess significant antitumorigenic activity. Gastric cancer is one of the most frequent cancers in the world, almost two-thirds of gastric cancer cases and deaths occur in less developed regions. But the effect of Astragalus membranaceus on proliferation, invasion and apoptosis of gastric cancer BGC-823 cells remains unclear. METHODS: Astragalus saponins were extracted. Cells proliferation was determined by CCK-8 assay. Cell cycle and apoptosis were detected by the flow cytometry. Boyden chamber was used to evaluate the invasion and metastasis capabilities of BGC-823 cells. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice. RESULTS: The results demonstrated that total Astragalus saponins could inhibit human gastric cancer cell growth both in vitro and in vivo, in additional, Astragalus saponins deceased the invasion ability and induced the apoptosis of gastric cancer BGC-823 cells. CONCLUSIONS: Total Astragalus saponins inhibited human gastric cancer cell growth, decreased the invasion ability and induced the apoptosis. This suggested the possibility of further developing Astragalus as an alternative treatment option, or perhaps using it as adjuvant chemotherapeutic agent in gastric cancer therapy.

A potential in vitro and in vivo anti-HIV drug screening system for Chinese herbal medicines.

Chinese herbal medicines are often applied as an alternative therapy for viral diseases. However, the development of anti-HIV herbal drugs has proceeded slowly, partly because of the lack of a high-throughput system for screening these drugs. The present study evaluated 16 herbal medicines for anti-HIV activities in vitro and in vivo. Herbal medicines were first screened for the ability to regulate C-X-C receptor 4 (CXCR4) and C-C receptor 5 (CCR5) promoter activities. A single-round pseudotyped HIV-luciferase reporter virus system (HIV-Luc) was used to identify potential anti-HIV mechanisms. CD4+ T cells from healthy volunteers were examined for changes in CXCR4 and CCR5 levels. HIV-1 replication was evaluated by ELISA. Spica Prunellae and Herba Andrographitis were found to down-regulate the activities of both the CXCR4 and CCR5 promoters. Also, Spica Prunellae and Herba Andrographitis (>1000 µM) inhibited HIV-1 in a dose-dependent manner. CXCR4 and CCR5 levels were reduced in CD4+ T cells from healthy volunteers (p<0.05). Spica Prunellae and Herba Andrographitis (EC50: 3.18 and 5.49 µg/mL, respectively) could suppress cell fusion and decrease p24 antigen. In conclusion, the data demonstrated that Spica Prunellae and Herba Andrographitis possessed anti-HIV-1 capabilities, perhaps through the inhibition of the CXCR4 and CCR5 promoters and HIV-1 replication.

[Effect and mechanism of Andrographitis Herba on human CD4+ T cell promoters CXCR4 and CCR5].

OBJECTIVE: Utilizing a gene reporter technique to study the effects of Andrographitis Herba on human CXCR4 and CCR5 promoters. METHOD: Inhibition of CXCR4 and CCR5 on T cells of healthy volunteers was analyzed by RT PCR, Western blot and flow cytometry. The human CXCR4 and CCR5 promoters driving a luciferase reporter in vectors pGLA. 17-CXCR4 and pGLA. 17-CCR5 were transfected into H9 stem cells. G418 was used for selecting stable cell lines. Rat sera thus medicated was collected and added to the transfected H9 cells, in which the expression of CXCR4 and CCR5 promoters was detected. RESULT: They showed that the mRNA and protein expression levels of CXCR4 and CCR5 in human CD4+ T cells decreased significantly after taking Andrographitis Herba (P<0.05). Furthermore human CXCR4 and CCR5 promoter activity was downregulated significantly by sera from rats medicated with Andrographitis Herba. CONCLUSION: Andrographitis Herba may have the effect of down-regulating CXCR4 and CCR5 promoters. It provides a feasible experimental platform for screening herbal medicine as the treatment of HIV/AIDS.

[Establishment and initial application of a medicine screening technique based on human promoter of CCR5].

This research ws carried out to construct a medicine screening system targeting at human promoter of CCR5. The gene Human promoter of CCR5 was inserted into the rebuilt vector pGL3-neo. The pGL3-neo-CCR5 plasmids were transfected into Jurkat cells (the cell line of acute T lymphocyte leukemia). The lasting transfected cells were screened by G418. After seven kinds of traditional Chinese medicine had acted separately on the lasting transfected cells for 16h, the expression levels of CCR5 promoter in the cells were detected. The results showed that the level of luciferase activity of Shuanghuanglian-injectio group was remarkably lower than that of control (P < 0.05), and the levels of luciferase activity of Chuanhuning group, Baical skullcap root group, and Milkvetch root group were remarkably higher than that of control (P < 0.01). Shuanghuanglian-injectio depressed the activity of the transfected CCR5 promoter in cells cultivated in vitro; Chuanhuning, Baical skullcap root and Milkvetch root boosted the activity of the transfected CCR5 promoter in cells cultivated in vitro. Thus a medicine screening system based on Human promoter of CCR5 was initially constructed.