Tailoring Iron-Ion Release of Cellulose-Based Aerogel-Coated Iron Foam for Long-Term High-Power Microbial Fuel Cells

The presence of iron(Fe) has been found to favor power generation in microbial fuel cells(MFCs). To achieve long-term power production in MFCs, it is crucial to effectively tailor the release of Fe ions over extended operating periods. In this study, we developed a composite anode(A/IF) by coating iron foam with cellulose-based aerogel. The concentration of Fe ions in the anode solution of A/IF anode reaches 0.280 μg/mL(Fe^(2+) vs. Fe^(3+) = 61%:39%) after 720 h of aseptic primary cell operation. This value was significantly higher than that(0.198 μg/mL, Fe^(2+) vs. Fe^(3+) = 92%:8%) on uncoated iron foam(IF), indicating a continuous release of Fe ions over long-term operation. Notably, the resulting MFCs hybrid cell exhibited a 23% reduction in Fe ion concentration(compared to a 47% reduction for the IF anode) during the sixth testing cycle(600-720 h). It achieved a high-power density of 301 ± 55 mW/m^(2) at 720 h, which was 2.62 times higher than that of the IF anode during the same period. Furthermore, a sedimentary microbial fuel cell(SMFCs) was constructed in a marine environment, and the A/IF anode demonstrated a power density of 103 ± 3 mW/m^(2) at 3240 h, representing a 75% improvement over the IF anode. These findings elucidate the significant enhancement in long-term power production performance of MFCs achieved through effective tailoring of Fe ions release during operation.

Lattice Boltzmann simulation study of anode degradation in solid oxide fuel cells during the initial aging process

For present solid oxide fuel cells(SOFCs),rapid performance degradation is observed in the initial aging process,and the dis-cussion of the degradation mechanism necessitates quantitative analysis.Herein,focused ion beam-scanning electron microscopy was em-ployed to characterize and reconstruct the ceramic microstructures of SOFC anodes.The lattice Boltzmann method(LBM)simulation of multiphysical and electrochemical processes in the reconstructed models was performed.Two samples collected from industrial-size cells were characterized,including a reduced reference cell and a cell with an initial aging process.Statistical parameters of the reconstructed microstructures revealed a significant decrease in the active triple-phase boundary and Ni connectivity in the aged cell compared with the reference cell.The LBM simulation revealed that activity degradation is dominant compared with microstructural degradation during the initial aging process,and the electrochemical reactions spread to the support layer in the aged cell.The microstructural and activity de-gradations are attributed to Ni migration and coarsening.

Novel Role of Calcium-Sensitive Receptors in Chronic Hypoxia-Induced Proliferation of Pulmonary Vein Smooth Muscle Cells

Objective:Vascular remodeling due to chronic hypoxia(CH)occurs not only in the pulmonary arteries but also in the pulmonary veins.Pulmonary vascular remodeling arises from the proliferation of pulmonary vascular myocytes.However,the mechanism by which CH induces the proliferation of pulmonary vein smooth muscle cells(PVSMCs)is unknown.This study aimed to investigate the mechanism by which CH affects the proliferation of PVSMCs.Methods:PVSMCs were isolated from rat distal pulmonary veins and exposed to CH(4%O2,60h),and the expression of the calcium-sensitive receptor(CaSR)was detected by Western blotting and immunofluorescence.MTT assay was used to detect the proliferation viability of the cells,and the changes in the intracellular calcium concentration were detected by laser confocal scanning technique.Results:CaSR expression was present in rat distal PVSMCs,and CaSR protein expression was upregulated under hypoxia.The positive regulator spermine not only enhanced CH-induced CaSR upregulation but also enhanced CH-induced increase in cell viability and calcium ion concentration.The negative CaSR regulator NPS2143 not only attenuated CH-induced CaSR upregulation but also inhibited CH-induced cell viability and calcium ion concentration.Conclusion:CaSR-mediated hyperproliferation is a novel pathogenic mechanism for the development of proliferation in distal PVSMCs under CH conditions.

Isolation of Protoplast and Ion Channel Recording in Plasma Membrane of Suspension Cells of Populus euphratica

The authors used suspension cells of Populus euphratica to isolate protoplast in the present study. Protoplasts were successfully obtained after 4 hours incubation in enzyme solution containing 1 0% cellulase “onozuka” R\|10, 0\^01% pectolyase Y\|23,0\^15% macerozyme R\|10 and 0\^1% hemicellulase at 25℃. Outward and inward single channels in plasma membrane were observed using cell\|attached recording of patch\|clamp technique. In this study, single channel records showed that more than one species of channel were obtained. These attempts in protoplast isolation and ion channel recording offers the opportunity to characterize cellular mechanisms of salt tolerance in tree species.

Ti/(Ti,Cr)N/CrN multilayer coated 316L stainless steel by arc ion plating as bipolar plates for proton exchange membrane fuel cells

Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Interfacial contact resistance (ICR) between the coated sample and carbon paper is 4.9 m Omega cm(2) under 150 N/cm(2), which is much lower than that of the SS316L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 mu A/cm(2). Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316L bipolar plate, presenting a great potential for PEMFC application. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

Simulated Microgravity Conditions and Carbon Ion Irradiation Induce Spermatogenic Cell Apoptosis and Sperm DNA Damage

Objective To investigate the effect of simulated microgravity and carbon ion irradiation （CIR） on spermatogenic cell apoptosis and sperm DNA damage to the testis of male Swiss Webster mice, and assess the risk associated with space environment. Methods Sperm DNA damage indicated by DNA fragmentation index （DFI） and high DNA stainability （HDS） was measured by sperm chromatin structure assay （SCSA）. Apoptosis of spermatogenic cells was detected by annexin V-propidium iodide assay. Bax （the expression levels of p53） and proliferating cell nuclear antigen （PCNAI were measured by immunoblotting; p53 and PCNA were located by immunohistology. Results HDS, DFI, apoptosis index, and the expression levels of p53 and Bax were detected to be significantly higher in the experimental groups （P〈0.05） compared with those in the control group, however, the PCNA expression varied to a certain degree, p53- and PCNA- positive expression were detected in each group, mainly in relation to the spermatogonic cells and spermatocytes. Conclusion The findings of the present study demonstrated that simulated microgravity and CIR can induce spermatogenic cell apoptosis and sperm DNA damage. Sperm DNA damage may be one of the underlying mechanisms behind male fertility decline under space environment. These findings may provide a scientific basis for protectint~ astronauts and space traveler＇s health and safety.

Ion migration in halide perovskite solar cells:Mechanism,characterization,impact and suppression

Metal halide perovskites are emerging as the most promising candidate for the next-generation Photovoltaics(PV)materials,due to their superior optoelectronic properties and low cost.However,the resulting Perovskite solar cells(PSCs)suffer from poor stability.In particular,the temperature and light activated ionic defects within the perovskite lattice,as well as electric-field-induced migration of ionic defects,make the PSCs unstable at operating condition,even with device encapsulation.There is no doubt that the investigation of ion migration is crucial for the development of PSCs with high intrinsic stability.In this review,we first briefly introduce the origin and pathways of ion migration,and also the essential characterization methods to identify ion migration.Next,we discuss the impact of ion migration on the perovskite films and cells with respect to photoelectric properties and stability.Then,several representative strategies to suppress ion migration are systematically summarized in the context of composition engineering,additive engineering and interface engineering,with an in-depth understanding on the underlying mechanisms which may provide more clues for further fabrication of PSCs with improved stability.Finally,a perspective with some suggestion on future research directions and chemical approaches are provided to alleviate ion migration in perovskite materials and the entire devices.

Two outward potassium current types are expressed during the neural differentiation of neural stem cells

The electrophysiological properties of potassium ion channels are regarded as a basic index for determining the functional differentiation of neural stem cells. In this study, neural stem cells from the hippocampus of newborn rats were induced to differentiate with neurotrophic growth factor, and the electrophysiological properties of the voltage-gated potassium ion channels were observed. Immunofluorescence staining showed that the rapidly proliferating neural stem cells formed spheres in vitro that expressed high levels of nestin. The differentiated neurons were shown to express neuron-specific enolase. Flow cytometric analysis revealed that the neural stem cells were actively dividing and the percentage of cells in the S ＋ G2/M phase was high. However, the ratio of cells in the S ＋ G2/M phase decreased obviously as differentiation proceeded. Whole-cell patch-clamp re- cordings revealed apparent changes in potassium ion currents as the neurons differentiated. The potassium ion currents consisted of one transient outward potassium ion current and one delayed rectifier potassium ion current, which were blocked by 4-aminopyridine and tetraethylammonium, respectively. The experimental findings indicate that neural stem cells from newborn rat hippo- campus could be cultured and induced to differentiate into functional neurons under defined condi- tions in vitro. The differentiated neurons expressed two types of outward potassium ion cur＇ents similar to those of mature neurons in vivo.

Identification and Function of Acid-sensing Ion Channels in RAW 264.7 Macrophage Cells

Activation of acid-sensing ion channels （ASICs） plays an important role in neuroinflammation. Macrophage recruitment to the sites of inflammation is an essential step in host defense. ASIC1 and ASIC3 have been reported to mediate the endocytosis and maturation of bone marrow derived macrophages. However, the expression and inflammation-related functions of ASICs in RAW 264.7 cells, another common macrophage, are still elusive. In the present study, we first demonstrated the presence of ASIC 1, ASIC2a and ASIC3 in RAW 264.7 macrophage cell line by using reverse transcriptase polymerase chain reaction （RT-PCR）, Western blotting and immunofluorescence experiments. The non-specific ASICs inhibitor amiloride and specific homomeric ASICla blocker PcTxl reduced the production of iNOS and COX-2 by LPS-induced activating RAW 264.7 cells. Furthermore, not only amiloride but also PcTxl inhibited the migration and LPS-induced apoptosis of RAW 264.7 cells. Taken together, our findings suggest that ASICs promote the inflammatory response and apoptosis of RAW 264.7 cells, and ASICs may serve as a potential novel target for immunological disease therapy.

REDUCTION OF FERRIC IRON IN THE TITANIUM SULFATE SOLUTION BY THE ION EXCHANGE MEMBRANE PRIMARY CELL METHOD

In the production process of titanium dioxide with sulfuric acid, the contamination of the titanium sulfate solution (the ilmenite leaching solution) in the Fe 3+ reduction stage by iron scraps is a practical problem because it is difficult to guarantee the quality of the iron scraps. In this research, a new method, called the ion exchange membrane primary cell method, for reduction of Fe 3+ in the titanium sulfate solution has been advanced. The positive compartment of the primary cell consists of lead (copper) electrode and the titanium sulfate solution, and the negative compartment consists of iron electrode and acidic FeSO 4 solution. The anion ion exchange membrane is used as the diaphragm between two compartments. Fe 3+ in the titanium sulfate solution is reduced by the electric discharge of the primary cell. The effects of temperature, stirring strength of the solution and membrane area on the reduction rate have been investigated. The experimental result shows that the optimum current density can be higher than 100 A/m 2.

Effects of operating conditions on the performance degradation and anode microstructure evolution of anode-supported solid oxide fuel cells

Performance degradation shortens the life of solid oxide fuel cells in practical applications.Revealing the degradation mechanism is crucial for the continuous improvement of cell durability.In this work,the effects of cell operating conditions on the terminal voltage and anode microstructure of a Ni-yttria-stabilized zirconia anode-supported single cell were investigated.The microstructure of the anode active area near the electrolyte was characterized by laser optical microscopy and focused ion beam-scanning electron microscopy.Ni depletion at the anode/electrolyte interface region was observed after 100 h discharge tests.In addition,the long-term stability of the single cell was evaluated at 700℃for 3000 h.After an initial decline,the anode-supported single cell exhibits good durability with a voltage decay rate of 0.72%/kh and an electrode polarization resistance decay rate of 0.17%/kh.The main performance loss of the cell originates from the initial degradation.

Realization of conformal doping on multicrystalline silicon solar cells and black silicon solar cells by plasma immersion ion implantation

Emitted multi-crystalline silicon and black silicon solar cells are conformal doped by ion implantation using the plasma immersion ion implantation （PⅢ） technique. The non-uniformity of emitter doping is lower than 5 %. The secondary ion mass spectrometer profile indicates that the PⅢ technique obtained 100-rim shallow emitter and the emitter depth could be impelled by furnace annealing to 220 nm and 330 nm at 850 ℃ with one and two hours, respectively. Furnace annealing at 850 ℃ could effectively electrically activate the dopants in the silicon. The efficiency of the black silicon solar cell is 14.84% higher than that of the mc-silicon solar cell due to more incident light being absorbed.

Copper Ions Stimulate the Proliferation of Hepatic Stellate Cells via Oxygen Stress in vitro

This study examined the effect of copper ions on the proliferation of hepatic stellate cells （HSCs） and the role of oxidative stress in this process in order to gain insight into the mechanism of he- patic fibrosis in Wilson＇s disease. LX-2 cells, a cell line of human HSCs, were cultured in vitro and treated with different agents including copper sulfate, N-acetyl cysteine （NAC） and buthionine sulfoxi- mine （BSO） for different time. The proliferation of LX-2 cells was measured by non-radioactive cell proliferation assay. Real-time PCR and Westem blotting were used to detect the mRNA and protein ex- pression of platelet-derived growth factor receptor 13 subunit （PDGFI3R）, ELISA to determine the level of glutathione （GSH） and oxidized glutathione （GSSG）, dichlorofluorescein assay to measure the level of reactive oxygen species （ROS）, and lipid hydroperoxide assay to quantify the level of lipid peroxide （LPO）. The results showed that copper sulfate over a certain concentration range could promote the pro- liferation of LX-2 cells in a time- and dose-dependent manner. The effect was most manifest when LX-2 cells were treated with copper sulfate at a concentration of 100 ~tmol/L for 24 h. Additionally, copper sulfate could dose-dependently increase the levels of ROS and LPO, and decrease the ratio of GSH/GSSG in LX-2 cells. The copper-induced increase in mRNA and protein expression of PDGF^R was significantly inhibited in LX-2 cells pre-treated with NAC, a precursor of GSH, and this phenome- non could be reversed by the intervention of BSO, an inhibitor of NAC. It was concluded that copper ions may directly stimulate the proliferation of HSCs via oxidative stress. Anti-oxidative stress therapies may help suppress the copper-induced activation and proliferation of HSCs.

Carbon ion irradiation-induced DNA damage evokes cell cycle arrest and apoptosis via the pRb/E2F1/c-Myc signaling pathway in p53-deficient prostate cancer PC-3 cells

Carbon ion radiotherapy has the advantages of better therapeutic effect and fewer side effects compared with those of X-rays in many kinds of tumors,including prostate cancer,and thus is an attractive treatment approach for prostate cancer.However,the biological effects and underlying mechanisms of carbon ion irradiation in prostate cancer are not yet fully understood.Therefore,this study systematically compared the effects of carbon ion irradiation with those of X-ray irradiation on DNA damage response and found that carbon ion irradiation was more effective than X-ray irradiation.Carbon ion irradiation can induce a high level of DNA double-strand break damage,reflected by the number of y-H2 A histone family member X foci,as well as by the foci lasting time and size.Moreover,carbon ion irradiation exhibited strong and long-lasting inhibitory effect on cell survival capability,induced prolonged cell cycle arrest,and increased apoptosis in PC-3 cells.As an underlying mechanism,we speculated that carbon ion irradiation-induced DNA damage evokes cell cycle arrest and apoptosis via the pRb/E2 F1/c-Myc signaling pathway to enhance the radiosensitivity of p53-deficient prostate cancer PC-3 cells.Collectively,the present study suggests that carbon ion irradiation is more efficient than X-ray irradiation and may help to understand the effects of different radiation qualities on the survival potential of p53-deficient prostate cancer cells.

Pt Deposition on Anode Enhances the Performance of Dye-Sensitized Solar Cell with Non-Cross-Linked Gel Electrolyte

We fabricated dye-sensitized solar cells with non-cross-linked fluorinated gel electrolyte. The application of fluorinated gel to electrolyte is a challenging issue at present. The gelation of the electrolyte is of importance in order to solve the problem in the durability of the cell. We investigated, in this article, the effect of Pt deposition on the anode of the cell. The Pt was deposited by means of a DC sputtering technique. The studies showed that the deposition time strongly affected both open voltage and short-circuit current of the cell. The adaptive thickness of the Pt layer was determined to be 10 nm for the non-cross-linked fluorinated gel electrolyte cells.

Applications and functions of rare-earth ions in perovskite solar cells

The emerging perovskite solar cells have been recognized as one of the most promising new-generation photovoltaic technologies owing to their potential of high efficiency and low production cost. However, the current perovskite solar cells suffer from some obstacles such as non-radiative charge recombination, mismatched absorption, light induced degradation for the further improvement of the power conversion efficiency and operational stability towards practical application. The rare-earth elements have been recently employed to effectively overcome these drawbacks according to their unique photophysical properties. Herein, the recent progress of the application of rare-earth ions and their functions in perovskite solar cells were systematically reviewed. As it was revealed that the rare-earth ions can be coupled with both charge transport metal oxides and photosensitive perovskites to regulate the thin film formation, and the rare-earth ions are embedded either substitutionally into the crystal lattices to adjust the optoelectronic properties and phase structure, or interstitially at grain boundaries and surface for effective defect passivation. In addition, the reversible oxidation and reduction potential of rare-earth ions can prevent the reduction and oxidation of the targeted materials. Moreover, owing to the presence of numerous energetic transition orbits, the rare-earth elements can convert low-energy infrared photons or high-energy ultraviolet photons into perovskite responsive visible light, to extend spectral response range and avoid high-energy light damage. Therefore, the incorporation of rare-earth elements into the perovskite solar cells have demonstrated promising potentials to simultaneously boost the device efficiency and stability.

Dose optimization of intrathecal administration of human umbilical cord mesenchymal stem cells for the treatment of subacute incomplete spinal cord injury

Human umbilical cord mesenchymal stem cells(hUC-MSCs)are a promising candidate for spinal cord injury(SCI)repair owing to their advantages of low immunogenicity and easy accessibility over other MSC sources.However,modest clinical efficacy hampered the progression of these cells to clinical translation.This discrepancy may be due to many variables,such as cell source,timing of implantation,route of administration,and relevant efficacious cell dose,which are critical factors that affect the efficacy of treatment of patients with SCI.Previously,we have evaluated the safety and efficacy of 4×10^(6) hUC-MSCs/kg in the treatment of subacute SCI by intrathecal implantation in rat models.To search for a more accurate dose range for clinical translation,we compared the effects of three different doses of hUC-MSCs-low(0.25×10^(6) cells/kg),medium(1×10^(6) cells/kg)and high(4×10^(6) cells/kg)-on subacute SCI repair through an elaborate combination of behavioral analyses,anatomical analyses,magnetic resonance imaging-diffusion tensor imaging(MRI-DTI),biotinylated dextran amine(BDA)tracing,electrophysiology,and quantification of mRNA levels of ion channels and neurotransmitter receptors.Our study demonstrated that the medium dose,but not the low dose,is as efficient as the high dose in producing the desired therapeutic outcomes.Furthermore,partial restoration of theγ-aminobutyric acid type A(GABAA)receptor expression by the effective doses indicates that GABAA receptors are possible candidates for therapeutic targeting of dormant relay pathways in injured spinal cord.Overall,this study revealed that intrathecal implantation of 1×10^(6) hUC-MSCs/kg is an alternative approach for treating subacute SCI.

Identification of key pathways and gene expression in the activation of mast cells via calcium flux using bioinformatics analysis

Mast cells are the main effector cells in IgE-associated allergic disorders,and we have reported that mucosal mast cells(MMCs)play a more important role in the development of food allergy(FA).IgE with antigen or calcium ionophore stimulation can lead to the activation of MMCs via a calcium-dependent pathway.The purpose of the present study was to identify gene signatures with IgE/antigen(dinitrophenyl-bovine serum albumin,DNP-BSA)or calcium ionophore(A23187)on the activation of MMCs.Differentially expressed genes between the two types of samples were identified with microarray analysis.Gene ontology functional and pathway enrichment analyses of differentially expressed genes were performed using the database for annotation,visualization,and integrated discovery software.The results showed that IgE/antigen and A23187 could induce degranulation,increase vacuoles,and elevate the cytosolic calcium concentration in MMCs.Furthermore,GeneChip analysis showed that the same 134 mRNAs were altered with IgE/DNP-BSA and A23187,suggesting that DNP-BSA/IgE and A23187 affect the same signal pathway partly in degranulation.KEGG analysis showed that the data were enriched in NF-κB,TNF,MAPK,transcription factor activity,DNA binding,and nucleic acid binding,suggesting that activation of MMCs is a complex process.The results provide new insights on MMCs activation.

Changes in Growth,Photosynthetic Pigments,Cell Viability,Lipid Peroxidation and Antioxidant Defense System in Two Varieties of Chickpea(Cicer arietinum L.)Subjected to Salinity Stress

Salinity is one of the most severe abiotic stresses for crop production.The present study investigates the salinityinduced modulation in growth indicators,morphology and movement of stomata,photosynthetic pigments,activity of carbonic anhydrase as well as nitrate reductase,and antioxidant systems in two varieties of chickpea(Pusa-BG5023,and Pusa-BGD72).On 20^(th) day of sowing,plants were treated with varying levels of NaCl(0,50,100,150 and 200 mM)followed by sampling on 45 days of sowing.Recorded observations on both the varieties reveal that salt stress leads to a significant decline in growth,dry biomass,leaf area,photosynthetic pigments,protein content,stomatal behavior,cell viability,activity of nitrate reductase and carbonic anhydrase with the rise in the concentration of salt.However,quantitatively these changes were less in Pusa-BG5023 as compared to Pusa-BGD72.Furthermore,salinity-induced oxidative stress enhanced malondialdehyde content,superoxide radicals,foliar proline content,and the enzymatic activities of superoxide dismutase,catalase,and peroxidase.The variety Pusa-BGD72 was found more sensitive than Pusa-BG5023 to salt stress.Out of different graded concentrations(50,100,150 and 200 mM)of sodium chloride,50 mM was least toxic,and 200 mM was most damaging.The differential behavior of these two varieties measured in terms of stomatal behavior,cell viability,photosynthetic pigments,and antioxidant defense system can be used as prospective indicators for selection of chickpea plants for salt tolerance and sensitivity.

S-doped porous carbon fibers with superior electrode behaviors in lithium ion batteries and fuel cells

The orientation construction of S-doped porous carbon fibers(SPCFs)is realized by the facile template-directed methodology using asphalt powder as carbon source.The unique fiber-like morphology without destruction can be well duplicated from the template by the developed methodology.MgSO4 fibers serve as both templates and S dopant,realizing the in-situ S doping into carbon frameworks.The effects of different reaction temperatures on the yield and S doping level of SPCFs are investigated.The S doping can not only significantly enhance the electrical conductivity,but also introduce more defects or disorders.As anode material for lithium ion batteries(LIBs),SPCFs electrode delivers better rate capability than undoped PCFs.And the capacity of SPCFs electrode retains around 90%after 300 cycles at 2 A g1,exhibiting good cycling stability.As the electrocatalysts for fuel cells,the onset potentials of SPCFs obtained at 800 and 900C are concentrated at 0.863 V,and the higher kinetic current densities at 0.4 V of them are larger than that of PCFs,demonstrating the superior electrocatalytic performance.Due to the synergistic effect of abundant pore channels and S doping,SPCFs electrode exhibits superior electrochemical performances as anode for LIBs and elecctrocatalyst for fuel cells,respectively.Additionally,the oriented conversion of asphalt powder into high-performance electrode material in this work provides a new way for the high value application of asphalt.