High yielded Co-C derived from polyester-Cobalt carbothermal reduction for efficient activation of peroxymonosulfate to degrade levofloxacin

A kind of high yield and recyclable Cobalt-Carbon composite (Zn₁Co₅/P_nC) was prepared by carbothermal reduction process, in which the cobalt acetate and zinc acetate were considered as Zn and Co precursors, and the polyester waste was evolved as the carbon precursor. The morphology, structure and composition of the composite were characterized using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Results showed that evaporation of zinc contributed to the formation of porous carbon structure, and the Co nanoparticles were wrapped and protected by the porous carbon matrix. The Zn₁Co₅/P_nC activated peroxymonosulfate (PMS) system (Zn₁Co₅/P_nC/PMS) was constructed to degrade the levofloxacin (LEV). The activity and mechanism of LEV degradation was understood. The LEV degradation efficiency was high to 96.60% within 90 min in the presence of Zn₁Co₅/P₄C. Moreover, the Zn₁Co₅/P₄C still maintained favorable PMS activation performance after five-cycle runs. The results show that the Zn₁Co₅/P₄C played positive role in activating the PMS, it may be due to the facts that the polyester derived carbon could supported the Co while the evaporated Zn could increase the surface area of Zn₁Co₅/P₄C, leading to the increased activity. The possible degradation pathways were proposed by identifying the intermediate products through liquid chromatography-mass spectrometry analysis. This study put forward a promising method to use polyester waste to synthesize high yield cobalt-carbon composite for degrading the antibiotic in wastewater.

Phosphate enhanced uranium stable immobilization on biochar supported nano zero valent iron

Uranium (U) immobilization from wastewater by zero valent iron (ZVI) was widely concerned through reduction and surface adsorption. Releasing of U due to re-oxidation of U(IV) into U(VI) limited the application of ZVI in U decontamination. In this work, a kind of biochar supported nano zero valent iron (Fe/BC(900)) was obtained by carbothermal reduction of starch mixed with ferric nitrate at 900 °C. U immobilization behavior by Fe/BC(900) in the presence of phosphate (P) was investigated. The U immobilization reaction was adjusted by controlling the sequence of U, Fe/BC(900) and P. U immobilization efficiency was enhanced to 99.9% in the presence of P. Reaction sequence of U, Fe/BC(900) and P influenced the U immobilization efficiency, which followed the order of (U-P)+Fe/BC(900)>(U- Fe/BC(900))+P>U+Fe/BC(900)>(P-Fe/BC(900))+U. P and nZVI both contributed to enhancing U immobilization through precipitation of uranyl-P and reductive co-precipitate (U(IV)) in a wide pH range. The released Fe ions could precipitate with uranyl and phosphate. Consumption of P and nZVI in the (P-Fe/BC(900))+U system limited U immobilization ability. The precipitate is highly dependent on U, P and Fe elements. U desorption in (U-P)+Fe/BC(900) system was not observed with stability.

Removal of levofloxacin through adsorption and peroxymonosulfate activation using carbothermal reduction synthesized nZVI/carbon fiber

Nano zero-valent iron (nZVI) is widely used for decontamination. The main issues associated with nZVI are agglomeration and oxidation in the long term. In this study, the carbothermal reduction of cotton fiber was conducted for the synthesis of nZVI supported on cotton carbon fiber (nZVI/CF) to address the agglomeration and oxidation of nZVI. Synergistic adsorption and peroxymonosulfate (PMS) activation using nZVI/CF for removing levofloxacin (LEV) are reported herein. The nZVI concentration and morphology were conveniently adjusted by soaking cotton fiber in ferric nitrate solutions of various Fe³⁺ concentrations. The carbothermal reduction of the cotton fiber at 900 °C contributed to the reduction of Fe³⁺ into nZVI. A nZVI/CF-900-0.3 system was obtained through the carbothermal reduction of cotton fiber soaked in 0.3 M ferric nitrate. Favorable adsorption of nZVI/CF-900-0.3 to LEV facilitated LEV degradation under PMS activation. Approximately 93.83% of LEV (C₀ = 20 ppm) was removed within 60 min with 0.2 g/L of the catalyst and 1 mM PMS. It was preferable to use nZVI + CF-900 to activate PMS for degrading LEV, thus confirming the favorable effect of LEV adsorption on further degradation. The nZVI/CF-900-0.3 exhibited excellent long-term stability given that it was able to activate PMS after it was stored for 6 months. ·SO₄^- played an important role in LEV degradation in the presence of PMS.

Advanced treatment of dye wastewater using a novel integrative Fenton-like/MnO2-filled upward flow biological filter bed system equipped with modified ceramsite

The deposal of residual hydrogen peroxide (H₂O₂) in Fenton-like system and the requirement of oxygen in bioreactor are essential parts for the treatment of integrative Fenton-like/bioreactor. A novel low-cost integrative Fenton-like and MnO₂-filled upward flow biological filter bed (Fenton-like/MBFB) equipped with the modified ceramsite was constructed to evaluate the main properties and catalytic activity of modified ceramsite, and the optimal conditions of integrative system and compare integrative and traditional systems. In this study, the Fenton-like reactor with modified ceramsite had higher catalytic ability whose Acid Orange 7 (AO7) degradation efficiency reached to 79.3% due to large surface area and high porosity, compared with that with raw ceramsite (44.3%). Furthermore, total utilization efficiency of H₂O₂ in integrative system (from 32.41% to 53.51%) and removal efficiencies of COD and AO7 were remarkably improved, which would effectively decrease the waste of H₂O₂ and the setting of regulation pool and aeration tank. Thus, the integrative system can save 0.51 CNY/m³ in construction cost and 0.21 CNY/m³ in operating cost. The average COD removal efficiency, AO7 degradation efficiency and effluent DO concentration were achieved to 64.8%, 79.5% and 9.3 mg/L respectively in integrative system were achieved in integrative system during sixty successive runs. Also, the potential degradation pathway of contaminants was also proposed according to the OH-enhanced at Fenton-like reactor due to catalyst and adsorption of modified ceramsite and the removal of microorganisms and modified ceramsite for contaminants at MBFB. This study demonstrated the feasibility of integrative Fenton-like/MBFB filled with modified ceramsite for simultaneously decreasing operational cost and complexity and enhancing removal efficiency, thus provided a one-step alternative for refractory dye wastewater.

Uranium extraction using hydroxyapatite recovered from phosphorus containing wastewater

A considerable amount of uranium (U(VI))-containing industrial wastewater is generated from both uranium mining and processing, and nuclear electrical power generation. Discharge of U(VI) containing wastewater causes severe damage to the environment and leads to a loss of resources. Uranium sorption on hydroxyapatite (HAP) has been studied extensively to address the abovementioned issues. In the present study, BC-HAP was recovered through phosphate sorption from wastewater, which was first reused as a potential sorbent for extracting uranium from aqueous solutions comparing to commercially available nano-HAP. The sorption behavior of uranium and its transformation on the recovered BC-HAP were investigated by conducting batch experiments as well as Fourier-transform infrared, scanning electron microscopy, and x-ray diffraction analyses. BC-HAP had superior sorption ability for uranium extraction. Autunite precipitant at nano-scale is observed after uranium sorption. Partial desorption of uranium was observed in the presence of Na₂CO₃ and NaHCO₃. Surface complexation and phosphate dissolution precipitation contributed to the favorable uranium sorption. Thus, recovered BC-HAP can be widely used as a promising and cost-effective adsorbent to extract uranium from aqueous solution.

Ultrasound assisted zero valent iron corrosion for peroxymonosulfate activation for Rhodamine-B degradation

In this work, ultrasound (US) irradiation assisted powder zero valent iron (ZVI) corrosion was conducted for peroxymonosulfate (PMS) activation. PMS activation activity was evaluated by Rhodamine-B (Rh B) degradation efficiency. The other US/PMS, ZVI/PMS, Fe²⁺/PMS and US/PMS/Fe²⁺ systems were performed to investigate the synergistic effects of US and ZVI on PMS activation activity. US/PMS/ZVI system performed the highest activity of Rh B degradation. 99.76% of Rh B was removed within 12 min under the optimum condition (pH = 4.5, ZVI dosage = 1 g/L, PMS = 1 mM, US power = 50 W). A comparison of US/PMS/ZVI system with PMS/ZVI and homogeneous US/PMS/Fe²⁺ systems for Rh B degradation was conducted, indicating that ultrasound irradiation contributed to acceleration of ZVI corrosion and removal of passive films. Besides, the electrons transformation from Fe⁰ to PMS made main contribution to the generation of sulfate radical, which resulted in the ability of degradation of Rh B. ZVI could be reused for five cycles with efficient activity of PMS activation. Exhaustion of ZVI led to the decrease in PMS activation at the sixth recycle. Thus, this work presents important information on understanding reuse of iron fillings for PMS/PS activation in practical application of pollution remediation.

Co-cultivation of Rhodotorula glutinis and Chlorella pyrenoidosa to improve nutrient removal and protein content by their synergistic relationship

With the continuous development of the livestock breeding industry, the amount of piggery wastewater discharged increases year by year, and the pressure of controlling environmental pollution continuously increases. A novel method using a co-culture of Chlorella pyrenoidosa and Rhodotorula glutinis in piggery wastewater was proposed in this study, which was aimed at treating piggery wastewater and producing useful products. The results showed that the optimal inoculum ratio of algae to yeast was 3 : 1 in the wastewater, which achieved the removal efficiencies of 58.53%, 36.07%, 33.20% and 56.25% for ammoniacal nitrogen (NH₃-N), total nitrogen (TN), total protein (TP) and chemical oxygen demand (COD), respectively, after 6 d. The synergistic relationship of C. pyrenoidosa and R. glutinis was preliminarily validated using the oxygen/carbon dioxide exchange balance and scanning electron microscopy images. The co-cultivation system gained 59.8% (w/w) protein within 5 d which can be used as a feed additive, and produces aquatic animals with better growth and quality. Thus, the 1000 litre pilot scale bioreactor was used indoors and removed 82.65% of TN, 53.51% of TP, 93.48% of NH₃-N and 85.44% of COD in 21 d which gave a better performance for TN (p < 0.05) than the bench scale results. This system improves the nutrition removal and protein production efficiencies, and is a promising method for piggery wastewater treatment and the pig breeding industry.

Aiming at treating piggery wastewater and producing useful products, a novel method using a co-culture of Chlorella pyrenoidosa and Rhodotorula glutinis in piggery wastewater was proposed in this study to improve nutrient removal and the protein content in the feed produced.

Recovery of phosphorus rich krill shell biowaste for uranium immobilization: A study of sorption behavior, surface reaction, and phase transformation

Increased generation of shrimp shell from exploitation of krill results in emerging biowaste pollution, in addition, uranium pollution has drawn public concern due to the rapid development of nuclear power, uranium mining, and nuclear fuel processing. In this study, krill shells were recovered and used as a potential natural biosorbent for uranium immobilization, thereby enabling both uranium decontamination and krill shell reutilization. Interaction of uranium with krill shell surface and their transformation were investigated by using batch sorption experiments, scanning electron microscopy, and transmission electron microscopy. Krill shell had high uranium sorption ability. Uranium was transformed into a nano-scale precipitate. The mapping of phosphorus and uranium was related to the nano-scale precipitate, indicating that sorption of uranium was dependent on phosphorus. Surface chemisorption between phosphate in krill shell and uranium as well as the formation of the nano-scale precipitate were interpreted as the mechanism of uranium immobilization. Thus, natural krill shell waste has potential for extensive use as a promising and cost-effective sorbent for uranium immobilization and krill shell reutilization.

Accelerated phosphorus recovery from aqueous solution onto decorated sewage sludge carbon

In search of efficient phosphorus resource recovery and pollution remediation should be highly concerned due to the view of phosphorus nonrenewable and eutrophication. This work presented a new insight into conversion of sewage sludge into favorable carbonaceous adsorbent for accelerated removing and recovering phosphorus from aqueous solution, what addressed the issues of phosphorus recovery and pollution remediation as well as sludge disposal. Ca and water hyacinth were evolved to decorate sludge derived carbon. Effect of mass ratio of sludge, water hyacinth and calcium carbonate on the morphologies and adsorption kinetics was investigated. The adsorbents (SW-Ca-112) resulted from sludge in the presence of water hyacinth and CaCO₃ in a mass ratio of 1:1:2 had the highest adsorption capacity of 49.50 mg/g P and adsorption rate. Decoration of Ca favored adsorption ability and the presence of water hyacinth accelerated the adsorption rate due to the enhanced porosity. Formation of acicular Ca₅(PO₄)₃OH nanoparticles contributed to the favorable adsorption process. Thus, the contribution of decorated Ca and water hyacinth to the adsorption ability and rate to phosphorus was understand, providing important information on resource utilization of sewage sludge as efficient adsorbent for immobilizing phosphorus from aqueous solution.

Synthesis of FC-supported Fe through a carbothermal process for immobilizing uranium

The abundant generation of uranium (U), a radioactive nuclide, engenders a severe hazard to the environment. Iron based materials were used to immobilize U from water, however, the immobilization is limited by the agglomeration of nanoparticle Fe. In this study, a novel carbothermal process was proposed to synthesize flour carbon (FC) supported nano-flake Fe (Fe-FC). Scanning electron microscopy (SEM) and nitrogen isotherm adsorption-desorption analysis were conducted to characterize Fe-FC. The immobilization characteristics were investigated through batch sorption experiments. Results indicated that nano-flake was appropriately dispersed on the surface. The sorption capacity reached 19.12 mg/g when the initial concentration of U and the dosage of Fe-FC were 20 mg/L and 1 g/L, respectively. Langmuir isotherm sorption and pseudo-second-order models were fitted well to sorption experimental data. The sorption mechanism is ascribed to surface chemisorptions between U(VI) and Fe-FC. Subsequently, X-ray diffraction (XRD) analysis validated that formation of Fe₂UO₃ contributed to the favorable immobilization of U and that Fe₂UO₃ was the fate of U.

Adsorption of phosphorus by calcium-flour biochar: Isotherm, kinetic and transformation studies

Discharging phosphorus (P)-contaminated water directly into the aquatic environment leads to resource loss and eutrophication. Thus, removing P from waste streams is imperative. In this study, calcium-decorated biochar (Ca-BC) in different mass ratios of Ca to BC was designed to effectively adsorb P from solution. Ca-BC was characterized through X-ray diffraction (XRD) analysis, followed by isotherm and kinetic adsorption experiments. The decorated Ca on the BC surface was found to have preferred P adsorption ability. A design of calcium hydroxide (Ca(OH)₂) to flour in a mass ratio of 2:1 was found to have a maximum adsorption capacity of 314.22 mg g^-1 for P. The Langmuir and pseudo-second-order models fit the sorption process adequately. XRD analysis indicated that the preferable adsorption ability to P was due to the reaction of Ca(OH)₂ and PO₄^3-, forming the hydroxylapatite (Ca₅(PO₄)₃(OH)) crystal. The P in solution was transformed to the crystal. Thus, Ca-BC is an environmental friendly and low-cost sorbent for P removal.

Nano-rod Ca-decorated sludge derived carbon for removal of phosphorus

Recovering phosphorus (P) from waste streams takes the unique advantage in simultaneously addressing the crisis of eutrophication and the shortage of P resource. A novel calcium decorated sludge carbon (Ca-SC) was developed from dyeing industry wastewater treatment sludge by decorating calcium (Ca) to effectively adsorb phosphorus from solution. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques were used to characterize the Ca-SCs, followed by isotherm and kinetic sorption experiments. A preferred design with CaCO₃ to sludge mass ratio of 1:2 was found to have a sorption capacity of 116.82 mg/g for phosphorus. This work reveals the crucial role of well-dispersed nano-rod calcium on the Ca-SC surface for the sorption of phosphorus. Moreover, the decoration of nano-rod calcium was found to further promote the uptake of phosphorus through the formation of hydroxylapatite (Ca₅(PO₄)₃(OH)). Thus, the development of decorated Ca-SC for sorption of phosphorus is very important in solving the P pollution and resource loss.

Subsurface low dissolved oxygen occurred at fresh- and saline-water intersection of the Pearl River estuary during the summer period

Estuarine oxygen depletion is one of the worldwide problems, which is caused by the freshwater-input-derived severe stratification and high nutrients loading. In this study we presented the horizontal and vertical distributions of dissolved oxygen (DO) in the Pearl River estuary, together with temperature, salinity, chlorophyll a concentration and heterotrophic bacteria abundance obtained from two cruises during the summer (wet) and winter (dry) periods of 2015. In surface water, the DO level in the summer period was lower and varied greater, as compared to the winter period. The DO remained unsaturated in the summer period if salinity is <12 and saturated if salinity is >12; while in the winter period it remained saturated throughout the estuary. In subsurface (>5m) water, the DO level varied from 0.71 to 6.65mgL^-1 and from 6.58 to 8.20mgL^-1 in the summer and winter periods, respectively. Particularly, we observed an area of ~1500km² low DO zone in the subsurface water with a threshold of 4mgDOL^-1 during this summer period, that located at the fresh- and saline-water intersection where is characterized with severe stratification and high heterotrophic bacteria abundance. In addition, our results indicate that spatial DO variability in surface water was contributed differently by biological and physio-chemical variables in the summer and winter periods, respectively.

Nanocalorimeter platform for in situ specific heat measurements and x-ray diffraction at low temperature

Recent advances in electronics and nanofabrication have enabled membrane-based nanocalorimetry for measurements of the specific heat of microgram-sized samples. We have integrated a nanocalorimeter platform into a 4.5 T split-pair vertical-field magnet to allow for the simultaneous measurement of the specific heat and x-ray scattering in magnetic fields and at temperatures as low as 4 K. This multi-modal approach empowers researchers to directly correlate scattering experiments with insights from thermodynamic properties including structural, electronic, orbital, and magnetic phase transitions. The use of a nanocalorimeter sample platform enables numerous technical advantages: precise measurement and control of the sample temperature, quantification of beam heating effects, fast and precise positioning of the sample in the x-ray beam, and fast acquisition of x-ray scans over a wide temperature range without the need for time-consuming re-centering and re-alignment. Furthermore, on an YBa₂Cu₃O_7-δ crystal and a copper foil, we demonstrate a novel approach to x-ray absorption spectroscopy by monitoring the change in sample temperature as a function of incident photon energy. Finally, we illustrate the new insights that can be gained from in situ structural and thermodynamic measurements by investigating the superheated state occurring at the first-order magneto-elastic phase transition of Fe₂P, a material that is of interest for magnetocaloric applications.

Nanostructured Stealth Surfaces for Visible and Near-Infrared Light

So far, all previous attempts to apply nanostructures for perfect transmission have not achieved maximum transmittance beyond 99.5% due to the limited regularity of the nanoscale surface geometry: too low for many high-end applications. Here we demonstrate a nanostructured stealth surface, with minimal reflectance (<0.02%) and maximal transmittance (>99.8%) for a wavelength range, covering visible and near-infrared. Compared to multilayer thin film coatings for near-infrared applications our antireflective surfaces operate within a much broader wavelength range, are mechanical stable to resist human touch or contamination, show a 44% higher laser-induced damage threshold, and are suitable for bended interfaces such as microlenses as well.

Optical racetrack resonator transduction of nanomechanical cantilevers

Optomechanical transduction has demonstrated its supremacy in probing nanomechanical displacements. In order to apply nano-optomechanical systems (NOMS) as force and mass sensors, knowledge about the transduction responsivity (i.e. the change in measured optical transmission with nanomechanical displacement) and its tradeoffs with system design is paramount. We compare the measured responsivities of NOMS devices with varying length, optomechanical coupling strength gom, and optical cavity properties. Cantilever beams 1.5 to 5 μm long are fabricated 70 to 160 nm from a racetrack resonator optical cavity and their thermomechanical (TM) noise signals are measured. We derive a generic expression for the transduction responsivity of the NOMS in terms of optical and mechanical system parameters such as finesse, optomechanical coupling constant, and interaction length. The form of the expression holds direct insight as to how these parameters affect the responsivity. With this expression, we obtain the optomechanical coupling constants using only measurements of the TM noise power spectra and optical cavity transmission slopes. All optical pump/probe operation is also demonstrated in our side-coupled cantilever-racetrack NOMS. Finally, to assess potential operation in a gas sensing environment, the TM noise signal of a device is measured at atmospheric pressure.

Degradation pathway of malachite green in a novel dual-tank photoelectrochemical catalytic reactor

A novel dual-tank photoelectrochemical catalytic reactor was designed to investigate the degradation pathway of malachite green. A thermally formed TiO₂/Ti thin film electrode was used as photoanode, graphite was used as cathode, and a saturated calomel electrode was employed as the reference electrode in the reactor. In the reactor, the anode and cathode tanks were connected by a cation exchange membrane. Results showed that the decolorization ratio of malachite green in the anode and cathode was 98.5 and 96.5% after 120 min, respectively. Malachite green in the two anode and cathode tanks was oxidized, achieving the bipolar double effect. Malachite green in both the anode and cathode tanks exhibited similar catalytic degradation pathways. The double bond of the malachite green molecule was attacked by strong oxidative hydroxyl radicals, after which the organic compound was degraded by the two pathways into 4,4-bis(dimethylamino) benzophenone, 4-(dimethylamino) benzophenone, 4-(dimethylamino) phenol, and other intermediate products. Eventually, malachite green was degraded into oxalic acid as a small molecular organic acid, which was degraded by processes such as demethylation, deamination, nitration, substitution, addition, and other reactions.

Silane-based coatings on the pyrite for remediation of acid mine drainage

Acid mine drainage (AMD) resulting from the oxidation of pyrite and other metal sulfides has caused significant environmental problems, including acidification of rivers and streams as well as leaching of toxic metals. With the goal of controlling AMD at the source, we evaluated the potential of tetraethylorthosilicate (TEOS) and n-propyltrimethoxysilane (NPS) coatings to suppress pyrite oxidation. The release of total Fe and SO4(-2) from uncoated and coated pyrite in the presence of a chemical oxidizing agent (H2O2) or iron-oxidizing bacteria (Acidithiobacillus ferrooxidans) was measured. Results showed that TEOS- and NPS-based coatings reduced chemical oxidation of pyrite by as much as 59 and 96% (based on Fe release), respectively, while biological oxidation of pyrite was reduced by 69 and 95%, respectively. These results were attributed to the formation of a dense network of Fe-O-Si and Si-O-Si bonds on the pyrite surface that limited permeation of oxygen, water, and bacteria. Compared with results for TEOS-coated pyrite, higher pH and lower concentrations of total Fe and SO4(-2) were observed for oxidation of NPS-coated pyrite, which was attributed to its crack-free morphology and the presence of hydrophobic groups on the NPS-based coating surface. The silane-based NPS coating was shown to be highly effective in suppressing pyrite oxidation, making it a promising alternative for remediation of AMD at its source.

miR-155* mediates suppressive effect of PTEN 3'-untranslated region on AP-1/NF-κB pathway in HTR-8/SVneo cells

Among miRNAs, miR-155 is a known regulator of immune system. Accumulating studies have revealed the connections between miR-155 and activator protein 1 (AP-1)/nuclear factor (NF)-κB. However, miR-155*, a miR-155 paralog, has so far been less studied. Here we demonstrated that miR-155*, induced by lipopolysaccharide (LPS) in an AP-1/NF-κB dependent manner, played a positive feedback role in AP-1/NF-κB pathway via targeting interleukin-1 receptor-associated kinase M (IRAKM) and NF-κB inhibitor interacting Ras-like 1 (NKIRAS1) in trophoblasts. Our study further proved that miR-155*-targeted PTEN 3'-untranslated region (3'UTR) increased IRAKM and NKIRAS1 expression by competing for miR-155* binding, thereby suppressing AP-1/NF-κB activation induced by LPS.

Near-infrared characterization of gallium nitride photonic-crystal waveguides and cavities

We report the design and optical characterization of fully suspended wire waveguides and photonic crystal (PhC) membranes fabricated on a gallium nitride layer grown on silicon substrate operating at 1.5 μm. W1-type PhC waveguides are coupled with suspended wires and are investigated using a standard end-fire setup. The experimental and theoretical dispersion properties of the propagating modes in the wires and photonic-crystal waveguides are shown. Modified L3 cavities with quality factors of up to 2200 and heterostructure cavities with quality factors of up to 5400 are experimentally demonstrated.

MicroRNA-155 inhibits proliferation and migration of human extravillous trophoblast derived HTR-8/SVneo cells via down-regulating cyclin D1

MiR-155 is known to participate in various cellular processes by targeting gene expression. We previously revealed a link between miR-155 and perturbation of trophoblast invasion and differentiation. This study aimed to investigate the target molecule(s) of miR-155 on the influence on the proliferation and migration of trophoblast cells. Bioinformatics analysis showed that, at the 3' untranslated region (UTR) of cyclin D1, six bases are complementary to the seed region of miR-155. Luciferase assays and cyclin D1 3'UTR transfection assays validated that cyclin D1 3'UTR was the target of miR-155 in HTR-8/SVneo cells. Overexpression of miR-155 in HTR-8/SVneo cells reduced the level of cyclin D1 protein, decreased cell proliferation and invasion, and increased cell number at the G1 stage. Furthermore, the increased expression of miR-155 also regulated the protein levels of kinase inhibitory protein p27 and phosphorylated cytoskeletal protein filamin A. In conclusion, we found that cyclin D1 may be a target of miR-155 in HTR-8/SVneo cells, and demonstrated a negative regulatory role of miR-155 involved in cyclin D1/p27 pathway in proliferation and migration of the cells.

Visible light induced photocatalytic reduction of Cr(VI) over polymer-sensitized TiO2 and its synergism with phenol oxidation

In this study, both Cr(VI) reduction and phenol oxidation induced by polymer-sensitized TiO(2) were investigated under visible light. Study of the reaction mechanism indicated that poly(fluorene-co-thiophene) (PFT) acted as a semiconductor and was by itself able to reduce Cr(VI) under visible light irradiation. When coupled with TiO(2), PFT served not only as the electron donor for Cr(VI) reduction, but also as a sensitizer. Upon irradiation by visible light, electrons in the sensitizing PFT polymer are excited and are transferred to the conduction band of TiO(2). PFT-catalyzed reduction of Cr(VI) was significantly promoted by the presence of phenol, and synergism between Cr(VI) reduction and phenol degradation was demonstrated both by analysis of the FT-IR spectrum of PFT/TiO(2) and by measuring the effect of repeated use of PFT/TiO(2) on its photocatalytic efficiency. The results provide a cost-effective method to remove organic and inorganic pollutants simultaneously in the complex wastewater.

NUR77 inhibits the expression of TIMP2 and increases the migration and invasion of HTR-8/SVneo cells induced by CYR61

OBJECTIVE

To investigate the function and mechanism of CYR61 on the migration and invasion of the trophoblast cell line, HTR-8/SVneo cells.

STUDY DESIGN

The mRNA and protein levels of NUR77 in the placentas of normal and preeclampsia (PE) women were evaluated using real-time PCR and Western blot, respectively. Paraffin-embedded tissues were processed for localization of NUR77 protein in placental villus by immunohistochemistry. HTR-8/SVneo cells were cultured in the presence of CYR61, Ad-NUR77 or a small interfering RNA for NUR77 (Ad-sinur77). The expression of NUR77 in the HTR-8/SVneo cells was detected and the effects of CYR61 on the migration and invasion of HTR-8/SVneo cells were assessed in wound-healing and transwell experiments, respectively. Gelatin zymography was used to measure the MMP2 release in HTR-8/SVneo cells.

RESULTS

NUR77 is significantly decreased in the placenta of women with PE compared with the levels during a normal pregnancy. CYR61 can significantly increase the expression of NUR77 in HTR-8/SVneo cells. CYR61, as well as NUR77, can promote HTR-8/SVneo cells migration and invasion, which can be blocked by Ad-sinur77. Both CYR61 and Ad-nur77 reduced the mRNA expression of TIMP2 in HTR-8/SVneo cells.

CONCLUSIONS

CYR61 may promote HTR-8/SVneo cells migration and invasion through the upregulation of NUR77, leading to the increase of MMP2 release and the downregulation of TIMP2 expression.

Treatment of angiostrongyliasis using a combination of albendazole and dexamethasone: the results of a retrospective and comparative study

As the information available on the treatment of angiostrongyliasis with a combination of albendazole and dexamethasone is limited, the efficacy of such therapy was assessed using data collected during the 2006 outbreak of angiostrongyliasis in Beijing. In a retrospective and controlled study, 35 patients treated with albendazole-dexamethasone (given 20 mg albendazole/kg and 3 mg dexamethasone daily for 7 days) were compared with 34 controls who were treated only symptomatically (with acetaminophen or other drugs). Compared with the controls, the patients given the combination were less likely to have headaches after 7 days (P = 0·038), tended to have headaches that cleared quicker (P = 0·010), and received fewer doses of acetaminophen (P = 0·036). Since no serious adverse effects were observed, a 1-week treatment with a combination of albendazole and dexamethasone appears both safe and beneficial in the treatment of angiostrongyliasis.

Perpendicular spin torques in magnetic tunnel junctions

We quantitatively determine a perpendicular spin torque in magnetic tunnel junctions by measuring the room-temperature critical switching current at various magnetic fields and current pulse widths. We find that the magnitude of the torque is proportional to the product of the current density and the bias voltage, and the direction of the torque reverses as the polarity of the voltage changes. By taking into account the energy-dependent inelastic scattering of tunnel electrons, we formulate the bias dependence of the perpendicular spin torque which is in qualitative agreement with the experimental results.

Differential inactivation of Listeria monocytogenes by d- and l-lactic acid

AIMS

To determine inactivation of Listeria monocytogenes by the two lactic acid isomers.

METHODS AND RESULTS

The survival of four strains with varying sensitivity to acid was determined following treatment with L- or D-lactic acid at 100 mmol l(-1) (pH 3.7) or HCl at pH 3.37. There was some, but not complete, similarity in the relative sensitivity of the four strains to the two types of acid. All strains were most sensitive to D-lactic acid, which gave 0.6-2.2 log units greater reduction than L-lactic acid midway in the inactivation curves. Even very low concentrations of the two isomers had an immediate effect on pH(i) which was identical for the two isomers.

CONCLUSIONS

The results show that L. monocytogenes is more sensitive to D- than to L-lactic acid; however, this difference is less than the strain variation in L-lactic acid sensitivity.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work has implications for the application of lactic acid for food preservation as well as for the understanding of the antibacterial mechanisms of weak organic acids.

[Construction of a novel Bm NPV Bac to Bac system]

A Bi-Shuttle vector Bm-Bacmid was constructed by co-infecting Bm N cells with wild type genomic DNA from BmNPV and Ac-Bacmid DNA. It could not only replicate in E. coli cells as a large plasmid and but also remain infectious when induced into Bm N or Sf9 cells. Recombinant virus rBmHBe was obtained after transposition of a donor plasmid carrying Hepatitis Be antigen gene (HBeAg) into att Tn7, and was demonstrated by Southern blotting. SDS-PAGE analysis showed that HBeAg gene were highly expressed in Bm N cells. By ELISA testing, the highest antigenecity titer of HBeAg protein in cell cultural medium was up to a dilution of 1:32,000. Although HBeAg protein also presented in the Bm N cells the titer was only 1:2000. The HBcAg protein was much fewer than HBeAg (< 1:160) whatever in culture medium and in cells. The results showed that Bm N cells was able to recognize the signal peptide sequence and cut it correctly for HBeAg protein's excreting production.