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Microbial electrosynthesis (MES) presents a versatile approach for efficiently converting carbon dioxide (CO2) into valuable products. However, poor electron uptake by the microorganisms from the cathode severely limits the performance of MES. In this study, a graphitic carbon nitride (g-C3N4)-metal–organic framework (MOF) i.e. HKUST-1 composite was newly designed and synthesized as the cathode catalyst for MES operations. The physiochemical analysis such as X-ray diffraction, scanning electron microscopy (SEM), and X-ray fluorescence spectroscopy showed the successful synthesis of g-C3N4-HKUST-1, whereas electrochemical assessments revealed its enhanced kinetics for redox reactions. The g-C3N4-HKUST-1 composite displayed excellent biocompatibility to develop electroactive biohybrid catalyst for CO2 reduction. The MES with g-C3N4-HKUST-1 biohybrid demonstrated an excellent current uptake of 1.7 mA/cm2, which was noted higher as compared to the MES using g-C3N4 biohybrid (1.1 mA/cm2). Both the MESs could convert CO2 into acetic and isobutyric acid with a significantly higher yield of 0.46 g/L.d and 0.14 g/L.d respectively in MES with g-C3N4-HKUST-1 biohybrid and 0.27 g/L.d and 0.06 g/L.d, respectively in MES with g-C3N4 biohybrid. The findings of this study suggest that g-C3N4-HKUST-1 is a highly efficient catalytic material for biocathodes in MESs to significantly enhance the CO2 conversion. [ABSTRACT FROM AUTHOR]

IL-27 is an IL-12 family cytokine with immune regulatory properties, capable of modulating inflammatory responses, including autoimmunity. While extensive studies investigated the major target cells of IL-27 mediating its functions, the source of IL-27 especially during tissue specific autoimmune inflammation has not formally been examined. IL-27p28 subunit, also known as IL-30, was initially discovered as an IL-27-specific subunit, and it has thus been deemed as a surrogate marker to denote IL-27 expression. However, IL-30 can be secreted independently of Ebi3, a subunit that forms bioactive IL-27 with IL-30. Moreover, IL-30 itself may act as a negative regulator antagonizing IL-27. In this study, we exploited various cell type specific IL-30-deficient mouse models and examined the source of IL-30 in a T cell mediated autoimmune neuroinflammation. We found that IL-30 expressed by infiltrating and CNS resident APC subsets, infiltrating myeloid cells and microglia, is central in limiting the inflammation. However, dendritic cell-derived IL-30 was dispensable for the disease development. Unexpectedly, in cell type specific IL-30 deficient mice that develop severe EAE, IL-30 expression in the remaining wild-type APC subsets is disproportionately increased, suggesting that increased endogenous IL-30 production may be involved in the severe pathogenesis. In support, systemic recombinant IL-30 administration exacerbates EAE severity. Our results demonstrate that dysregulated endogenous IL-30 expression may interfere with immune regulatory functions of IL-27, promoting encephalitogenic inflammation in vivo. [ABSTRACT FROM AUTHOR]

Biogenic nanocrystals (NCs) were synthesized from Ginkgo biloba leaf extract (GLE) and applied as photocatalytic and antibacterial agents. XRD patterns revealed the formation of ZnO/CuO NCs with a crystalline quality and intra-granular coupling, and HRTEM images showed the globular morphology indicating a porous nature. The lower PL intensity of ZnO/CuO NCs specified the slower recombination rate of electrons and holes for enhanced photocatalytic and antibacterial activity. The maximum photocatalytic degradation efficiency of methylene blue dye was 99% with ZnO/CuO NCs after 60 min under ultraviolet A (UV-A) light, which is much higher than the as-prepared (bare) NCs (75% for ZnO and 36% for CuO). For methylene orange (MO), the photocatalysis with ZnO/CuO NCs resulted in 83% removal efficiency in comparison to the bare ZnO and CuO (31% and 52%), respectively. The dye degradation with ZnO/CuO NCs followed pseudo-first-order kinetics and also exhibited excellent recycling stability even after five cycles. The antibacterial studies shows that gram-negative bacteria are efficiently killed by the NCs due to the surface interaction of the NCs and evolution of reactive oxygen species over the cell wall membranes. The photocatalytic active species correlated with the photodegradation mechanism of ZnO/CuO NCs and reactive oxygen species-based antibacterial activity. This study suggests that biogenic NCs can be used as a promising alternative photocatalyst for dye degradation in wastewater and also as a sustainable antibacterial agent. [ABSTRACT FROM AUTHOR]

The performance of an air-cathode microbial fuel cell (MFC) with a cap arrangement was significantly affected by humidity conditions in the cathode. An MFC at a relative humidity (RH) of 88% produced a highest cell voltage of 0.42 V (600 Ω) compared to other operations at 50% (0.34 V) and 30% (0.29 V) RHs. During polarization analysis, MFC operation at 88% RH produced a maximum power density of 0.377 W/m2 (a current density of 1.5 A/m2), which was 1.8 and 2.9 times higher than with 50% and 30% RHs, respectively. Cyclic voltammogram analysis revealed a higher reduction current of − 0.073 A with 88% RH. Furthermore, no increase in dissolved oxygen concentration in the anode chamber was observed with 88% RH. This result suggests that control of humidity conditions in cathode chamber could maximize power generation from an air-cathode MFC. [ABSTRACT FROM AUTHOR]

The performance of a single chamber microbial fuel cell (MFC) with a low-cost polypropylene separator was investigated at various electrode interspaces in a separator electrode assembly (SEA). The lag period was shortened (3.74-0.17 days) and voltage generation was enhanced (0.2-0.5 V) as electrode spacing was increased from 0 to 9 mm. Power density was increased from 220 to 370 mW/m with increased spacing. The highest power density of 488 mW/m was obtained in polarization analysis with 6 mm. The oxygen mass transfer coefficients with 0 mm ( K = 3.69 × 10 cm/s) electrode spacing were 3.8 times higher than with 9 mm ( K = 0.96 × 10 cm/s) spacing. Columbic efficiency (CE) was increased from 5 to 32% due to less oxygen diffusion with increase in electrode spacing, but on contrary the ohmic resistance ( R ) was increased from 2 to 4 Ω. In a long-term operation (200 days), a gradual decrease in cathode potentials was observed in all electrode spacing as the main limiting factor of stable MFC performance. [ABSTRACT FROM AUTHOR]

High concentration of total ammonia nitrogen (TAN) in the form of urea is known to inhibit the performance of many biological wastewater treatment processes. Microbial fuel cells (MFCs) have great potential for TAN removal due to its unique oxic/anoxic environment. In this study, we demonstrated that increased urea (TAN) concentration up to 3940 mg/L did not inhibit power output of single-chambered MFCs, but enhanced power generation by 67% and improved coulombic efficiency by 78% compared to those obtained at 80 mg/L of TAN. Over 80% of nitrogen removal was achieved at TAN concentration of 2630 mg/L. The increased nitrogen removal coupled with significantly enhanced coulombic efficiency, which was observed for the first time, indicates the possibility of a new electricity generation mechanism in MFCs: direct oxidation of ammonia for power generation. This study also demonstrates the great potential of using one MFC reactor to achieve simultaneous electricity generation and urea removal from wastewater. [ABSTRACT FROM AUTHOR]

The effect of insecticides (acephate and imidacloprid) on a freshwater microalga Chlamydomonas mexicana was investigated with respect to photosynthetic pigments, carbohydrate and protein contents, fatty acids composition and induction of stress indicators including proline, superoxide dismutase (SOD) and catalase (CAT). C. mexicana was cultivated with 1, 5, 10, 15, 20 and 25 mg L of acephate and imidacloprid. The microalga growth increased with increasing concentrations of both insecticides up to 15 mg L, beyond which the growth declined compared to control condition (without insecticides). C. mexicana cultivated with 15 mg L of both insecticides for 12 days was used for further analysis. The accumulation of photosynthetic pigments (chlorophyll and carotenoids), carbohydrates and protein was decreased in the presence of both insecticides. Acephate and imidacloprid induced the activities of superoxide dismutase (SOD) and catalase (CAT) and increased the concentration of proline in the microalga, which play a defensive role against various environmental stresses. Fatty acid analysis revealed that the fraction of polyunsaturated fatty acids decreased on exposure to both insecticides. C. mexicana also promoted 25 and 21 % removal of acephate and imidacloprid, respectively. The biochemical changes in C. mexicana on exposure to acephate and imidacloprid indicate that the microalga undergoes an adaptive change in response to the insecticide-induced oxidative stress. [ABSTRACT FROM AUTHOR]

A novel isolated bacterium Rhodococcus sp. YSPW03 was able to reduce high concentrations (up to 700 mg L) of perchlorate using acetate as electron donor. Perchlorate reduction rate increased from 2.90 to 11.23 mg L h with increasing initial acetate concentration from 100 to 2000 mg L, leading to complete removal of perchlorate (100 mg L) within 9 h. The bacterium also promoted complete reduction of high perchlorate concentrations (500 and 700 mg L) at 2000 mg L of acetate within 48 and 96 h, respectively. Under semi-continuous reactor operation, efficient reduction on varied perchlorate concentrations (80-700 mg L) was performed by the bacterium in presence of acetate (600-6000 mg L) over 140 days. The highest perchlorate reduction rate of 280 mg L day was observed with an initial perchlorate concentration of 570 mg L at day 34. Dissolved chloride ions of 1000 mg L in the semi-continuous reactor (SCR) completely inhibited the biological perchlorate reduction. The findings of this study will help improve the perchlorate bioreactor design and determine the optimal conditions to maximize the perchlorate reduction efficiency. [ABSTRACT FROM AUTHOR]

Microbial fuel cell (MFC) and its cathode performances were compared with use of carbon fiber brush and plain carbon paper cathode electrodes in algae aeration. The MFC having carbon fiber brush cathode exhibited a voltage of 0.21 ± 0.01 V (1,000 Ω) with a cathode potential of around −0.14 ± 0.01 V in algal aeration, whereas MFC with plain carbon paper cathode resulted in a voltage of 0.06 ± 0.005 V with a cathode potential of −0.39 ± 0.01 V. During polarizations, MFC equipped with carbon fiber brush cathode showed a maximum power density of 30 mW/m, whereas the MFC equipped with plain carbon paper showed a power density of 4.6 mW/m. In algae aeration, the internal resistance with carbon fiber brush cathode was 804 Ω and with plain carbon paper it was 1,210 Ω. The peak currents of MFC operation with carbon fiber brush and plain carbon paper cathodes were −31 mA and −850 µA, respectively. [ABSTRACT FROM AUTHOR]

Renewable algae biomass, Scenedesmus obliquus, was used as substrate for generating electricity in two chamber microbial fuel cells (MFCs). From polarization test, maximum power density with pretreated algal biomass was 102 mW·m (951 mW·m) at current generation of 276 mA·m. The individual electrode potential as a function of current generation suggested that anodic oxidation process of algae substrate had limitation for high current generation in MFC. Total chemical oxygen demand (TCOD) reduction of 74% was obtained when initial TCOD concentration was 534 mg ·L for 150 h of operation. The main organic compounds of algae oriented biomass were lactate and acetate, which were mainly used for electricity generation. Other byproducts such as propionate and butyrate were formed at a negligible amount. Electrochemical Impedance Spectroscopy (EIS) analysis pinpointed the charge transfer resistance (112 Ω) of anode electrode, and the exchange current density of anode electrode was 1214 nA·cm. [ABSTRACT FROM AUTHOR]

Changes in the characteristics of algae-derived organic matter (AOM) were examined upon the operation of a microbial fuel cell (MFC) using multiple analytical methods. Temporal variations in the UV absorption and fluorescence excitation-emission matrix of the AOM revealed that less condensed humic-like components and large-sized protein-like fluorescent compounds were preferentially decomposed over the period of electricity generation. They also showed that low UV-absorbing extracellular organic matters (EOM) were produced at the end of the operation. SEC chromatograms demonstrated that smaller-sized UV-absorbing components were initially decomposed, followed by the net production of EOM with an intermediate molecular weight. Fourier transform infrared (FT-IR) spectra showed that proteins and polysaccharides were the two most dominant structures of the AOM in the MFC. Two-dimensional correlation spectroscopy combined with FT-IR provided additional valuable information on the sequential changes of the AOM, which occurred in the order of proteins → acidic functional groups → polysaccharides → amino acids/proteins. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) have received attention as a promising renewable energy technology for waste treatment and energy recovery. We tested a submersible MFC with an innovative design capable of generating a stable voltage of 0.250 ± 0.008 V (with a fixed 470 Ω resistor) directly from primary sludge. In a polarization test, the maximum power density was 0.18 W/m at a current density of 0.8 A/m with an external resistor of 300 Ω. The anodic solution of the primary sludge needs to be adjusted to a pH 7 for high power generation. The modified primary sludge with an added phosphate buffer prolonged the current generation and increased the power density by 7 and 1.5 times, respectively, in comparison with raw primary sludge. These findings suggest that energy recovery from primary sludge can be maximized using an advanced MFC system with optimum conditions. [ABSTRACT FROM AUTHOR]

Electrochemical treatment of nitrate ions was attempted using different catalysts on the cathode in bioelectrochemical denitrification systems. The carbon cathode coated by biofilm (biocathode) could remove 91 % of nitrate ions at 1.0 V, which was almost same as the Pt-coated electrode (90 %). The exchange current density of biocathode was 0.0083 A/m, which was almost 22 times higher than with an abiotic plain carbon cathode. The formation of intermediate products in nitrate reduction varied depending on the cell voltage. At 0.5 V, a large portion of nitrate was converted to ammonia, but at more increased cell voltage (0.7 and 1 V) a high amount of nitrite ions was found with little ammonia formation in cathodic solution. The maximum nitrate removal rate was 0.204 mg NO-N/cmd by biocathode, while plain carbon paper showed only 0.176 mg NO-N/cmd. Electrochemical analysis of chronoamperometry showed a higher stable current generation for biocathode (3.1 mA) and Pt-coated cathode (2.8 mA) as compared to plain carbon (0.6 mA) at 0.7 V of poised voltage. [ABSTRACT FROM AUTHOR]

A one-step model calibration methodology of the activated sludge model no. 1 (ASM1) of a full-scale wastewater treatment plant (WWTP) is proposed. First, the key parameters among all parameters of the ASM1 model are selected by sensitivity analysis based on the effluent quality index. Second, multiple response surface methodology (MRSM) is conducted to find the optimal parameter values of the ASM1 model. Lastly, an MRSM analysis is conducted in order to determine the optimal parameter values. This study was conducted in order to develop a new systematic model calibration methodology that can greatly help the modeler to find the optimal solution by selecting the key parameters and optimizing the parameters. In two case studies of simple activated sludge process and a full-scale plant, the experimental results indicated that the calibrated models can improve the prediction quality of the ASM model and the efficiency of the modeling. [ABSTRACT FROM AUTHOR]

Basophils, the least abundant granulocytes, have poorly understood functions. They have been linked to the development of T helper type 2 immunity during parasite infection and allergic inflammation. Emerging evidence has not only shown the critical involvement of basophils in the development of T helper type 2 immunity but also provided useful animal models with which basophil functions can be further examined. However, distinctions must be made between what basophils 'can do' after in vitro manipulation and what they 'actually do' during in vivo immune responses; these may be very different. In this review, the functions of basophils determined on the basis of analysis of in vitro and in vivo systems and their potential involvement in clinical settings are discussed. [ABSTRACT FROM AUTHOR]

The performance of a microbial fuel cell (MFC) was investigated at different temperatures and anodic media. A lag phase of 30 h occurred at 30°C which was half that at room temperature (22°C). The maximum power density at 30°C was 70 mW/m2 and at 22°C was 43 mW/m2. At 15°C, no successful operation was observed even after several loadings for a long period of operation. Maximum power density of 320 mW/m2 was obtained with wastewater medium containing phosphate buffer (conductivity: 11.8 mS/cm), which was approx. 4 times higher than the value without phosphate additions (2.89 mS/cm). [ABSTRACT FROM AUTHOR]

Expression of the transcription factor GATA-3 is strongly associated with T helper type 2 (TH2) differentiation, but genetic evidence for its involvement in this process has been lacking. Here, we generated a conditional GATA-3-deficient mouse line. In vitro deletion of Gata3 diminished both interleukin 4 (IL-4)-dependent and IL-4-independent TH2 cell differentiation; without GATA-3, TH1 differentiation occurred in the absence of IL-12 and interferon-γ. Gata3 deletion limited the growth of TH2 cells but not TH1 cells. Deletion of Gata3 from established TH2 cells abolished IL-5 and IL-13 but not IL-4 production. In vivo deletion of Gata3 using OX40-Cre eliminated TH2 responses and allowed the development of interferon-γ-producing cells in mice infected with Nippostrongylus brasiliensis. Thus, GATA-3 serves as a principal switch in determining TH1-TH2 responses. [ABSTRACT FROM AUTHOR]

T cells constitute a heterogeneous, hierarchically organized population, comprising several maturation/differentiation states that have different capacities for clonal expansion and self-renewal. Here, we argue that the relative probabilities of proliferation, differentiation and death - the cellular events that determine the population's structure, as well as its size - are not entirely pre-programmed or fixed; instead, these events are regulated dynamically through the recurrent interaction of lymphocytes with exogenous and endogenous antigens, antigen-presenting cells and each other. [ABSTRACT FROM AUTHOR]