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A single-stage phosphorylated polyvinyl alcohol immobilized-cell reactor with three operation modes was employed to investigate the efficiency of simultaneous carbon/nitrogen removal from raw swine wastewater. In continuous aeration mode, the removal efficiency of chemical oxygen demand (COD) and total nitrogen (T-N) exceeded 70 and 8%, respectively, at hydraulic retention time of 10 days. In intermittent aeration (IA) mode, the removal efficiency of COD and T-N was more than 85 and 46%, respectively, when the reactor was set at 50% aeration duration to cycle time to operate at three aerobic-anoxic cycles per day. When oxidation-reduction-potential control was adopted to control the duration of the anoxic period in the real-time controlled (RTC) IA mode for a 4 h aeration period, the total cycle time was reduced by about 20% with a slight increase in removal efficiency of COD (87%) and T-N (47%). The system with no extra chambers required is efficient in simultaneous carbon/nitrogen removal. DOI: 10.1061/(ASCE)0733-9372(2006)132:3(423) CE Database subject headings: Simulation; Abatement and removal; Carbons; Nitrogen; Wastewater management; Reactors.

In this paper, we compare the helium-based atmospheric pressure plasma jets (APPJs) with power-ground (PG) and power-floating (PF) configurations by using optical analysis. We find that the PG jet traps plasma between two electrodes (discharge region); thus, the hydroxyl radical intensity is significantly strong in discharge region; however, the plasma intensity in downstream region is relatively weak as compared with that of PF configuration. In contrast, using the APPJ with PF configuration, the hydroxyl radical and nitric oxide are approximately two and three times stronger, respectively, in the downstream region, even though the gas temperature and power consumption are lower. The PF jet successfully eradicates S. mutans and decreases water contact angle by ~40 within 15-s treatment, which demonstrates higher efficient than that of PG jet, and shows highly potential for dental filling demand. [ABSTRACT FROM PUBLISHER]

In this article, we report the development of the fast incorporation of primary amine functional groups into a polylactide (PLA) surface using the post-discharge jet region of an atmospheric-pressure nitrogen-based dielectric barrier discharge (DBD). Plasma treatments were carried out in two sequential steps: (1) nitrogen with 0.1% oxygen addition, and (2) nitrogen with 5% ammonia addition. The analyses show that the concentration of N/C ratio, surface energy, contact angle, and surface roughness of the treated PLA surface can reach 19.1%, 70.5 mJ/m2, 38° and 73.22 nm, respectively. In addition, the proposed two-step plasma treatment procedure can produce a PLA surface exhibiting almost the same C2C12 cell attachment and proliferation performance as that of the conventional gelatin coating method. Most importantly, the processing/preparation time is reduced from 13-15 h (gelatin coating method) to 5-15 min (two-step plasma treatment), which is very useful in practical applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 160-169, 2014. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate that, by adding a small amount of \CF4 (2\%) into a compressed-air planar dielectric barrier discharge (DBD), one can effectively inactivate a B. subtilis spore up to 50 mm in width in the postdischarge jet region after ten passes of exposure of plasma plume (equivalent plasma exposure time of 1 s) for treatment distance of up to 14 mm for the spore concentration in the range of 10^5-10^7 CFU/mL. A possible mechanism is proposed, i.e., the chemically active F atoms and \CFn\ ({n} = 1 - 3) are generated through the help of abundant excited nitrogen molecules in the postdischarge region. [ABSTRACT FROM PUBLISHER]

The aim of this research is to use Clerodendrum fragrans leaf powder as a biosorbent to extract crystal violet (CV) dye from textile wastewater in a batch study. Contact time, solution pH, initial CV dye concentration, biosorbent dosage, average particle size of the biosorbent, and temperature all had an impact on the method. Thermodynamic, kinetic, and isotherm studies of the effects of removing CV dye from Clerodendrum fragrans biosorbent were studied. The response surface methodology (RSM) was used to investigate the relationships between the process parameters that affect the process and to optimize it for high dye removal. The maximum removal efficiency was predicted to be 96.72% for crystal violet, which was obtained at a temperature of 303.90 K, solution pH of 5.03, initial dye concentration of 19.44 mg/L, and biosorbent dosage of 1.27 g. Using Clerodendrum fragrans leaves as a biosorbent, the uptake of crystal violet dye was found to be 13.50 mg/g in this analysis. [ABSTRACT FROM AUTHOR]

Scaffold surface properties and mechanical stimuli have been known to have a critical influence on cell proliferation and extracellular matrix synthesis in cultured cells for tissue engineering. Hydrophilic surface and hydrodynamic pressure (HP) stimulation have been shown to have a beneficial effect on chondrocyte activity. The aim of this study was, thus, to assess the synergic influences of HP and hydrophilic coating on cell activity using primary porcine chondrocytes inoculated in hydrophilic-coated poly(lactide-co-glycolide) (PLGA) sponge scaffolds. The natural materials hyaluronic acid (HA), chitosan and HA/chitosan were cross-linked on porous PLGA as a hydrophilic surface modification. HP was applied to scaffolds at an amplitude of 2.24 MPa and a frequency of 0.1 Hz for 30 min per day, twice a week, over a period of 28 days. Cell activities were determined by the MTS assay and the dimethylmethylene blue assay for glycosaminoglycan (GAG) quantification. Our results displayed that PLGA coated with both HA and chitosan had the best hydrophilicity (contact angle 49.46°) and initial compressive modulus (1.10 ± 0.13 MPa) among the tested scaffold groups. Additionally, HP stimulation enhanced cell proliferation as well as GAG production (up to 3-fold in culture medium and 15-fold in scaffolds at 28 days compared to static culture of PLGA alone in the scaffold group) in the hydrophilic-coated scaffold groups. The synergistic benefit from hydrophilic coating and HP stimulation may be imperative in regenerating engineered cartilage in the long-term. [ABSTRACT FROM AUTHOR]

To improve antagonistic metabolites production of Bacillus subtilis strain BS501a, physical parameters of fermentation and metal inorganic salts in medium, namely initial pH value, culture temperature, fermentation time, concentrations of CaCl, FeSO, ZnSO, MnSO and MgSO, were optimized using one-factor-at-a-time and orthogonal tests. The results show that the optimal physical parameters of fermentation are an initial pH of 7.0, a culture temperature of 30 °C, and a fermentation time of 48 h. The optimal concentrations of metal inorganic salts in basal medium are 10.2 mmol/L CaCl, 0.4 mmol/L FeSO, 3.5 mmol/L ZnSO, 0.6 mmol/L MnSO and 2.0 mmol/L MgSO. Among the metal inorganic salts, MgSO and MnSO play important roles in the improvement of the antagonistic metabolites production of B. subtilis strain BS501a; especially, MgSO contributes a highly significant effect. The average diameter of inhibition zone of the BS501a filtered fermentation supernatant (FFS) cultured in the optimal fermentation conditions against Magnaporthe grisea DWBJ329 reaches 71.4 mm, and there is 2.4-fold increase in antifungal activity as compared with 21.2 mm under the pre-optimized conditions. [ABSTRACT FROM AUTHOR]

Abstract: The fermentation of Grifola frondosa was investigated in the shake flasks and a 5-L jar fermenter in batch and fed-batch modes. In the shake-flask experiments, the preferable mycelial growth and exopolysaccharide (EPS) production was observed at relatively low pH; maltose and glucose were preferred carbon sources for high mycelial production. The EPS was doubled after 13 d of cultivation when glucose was increased from 2% to 4%. Yeast extract (YE) (0.4%) in combination with corn steep powder (CSP) (0.6%) and YE (0.8%) in combination with CSP (1.2%) were preferred nitrogen sources for high mycelial production and EPS production, respectively. All plant oils tested significantly stimulate cell growth of G. frondosa but they failed to enhance EPS production. The EPS products usually consisted of two fractions of different molecular sizes varied by the plant oils used. The fed-batch fermentation by glucose feeding was performed when the glucose concentration in the medium was lower than 0.5% (5g/L), which greatly enhanced the accumulation of mycelial biomass and EPS; the mycelial biomass and EPS were 3.97g/L and 1.04g/L before glucose feeding, which reached 8.23g/L and 3.88g/L at 13 d of cultivation. In contrast, the mycelial biomass and EPS in the batch fermentation were 6.7g/L and 3.3g/L at 13 d of cultivation. [Copyright &y& Elsevier]