Nitrogen removal from the saline sludge liquor by electrochemical denitrification

Sludge liquor from the sludge dewatering process has a high ammonia content. In the present study, a lab-scale electrochemical (EC) system with a pair of Ti electrode plates was used for treating the sludge centrate liquor of digested wastewater sludge with a NH4 + - N content of around 500 mg/L. The sludge liquor had a high salinity due to seawater being used for toilet flushing in Hong Kong. The results show that the EC process is highly effective for denitrification of the saline sludge liquor. Complete nitroger removal could be achieved within 1 hr or so. The rate of EC denitrification increased with the current intensity applied. The best current efficiency for nitrogen removal was obtained for a gap distance between the electrodes at 8 mm. Electro-chlorination was considered to be the major mechanism of EC denitrification. The formation of chlorination by-products (CBPs) appeared to be minimal with the total trihalomethanes (THM) detected at a level of 300 μg/L or lower. The power consumption for EC denitrification was around 23 kWh/kg N. Additional electro-flocculation with a pair of iron needle electrodes could enhance the flocculation and subsequent sedimentation of colloidal organics in the sludge liquor, increasing the organic removal from less than 30% to more than 70%. Therefore, the EC process including both electro-denitrification and electro-flocculation can be developed as the most cost-effective method for treatment of the saline sludqe liquor. © IWA Publishing 2006.postprin

1α, 25-dihydroxyvitamin D3 suppresses differentiation, maturation and activation of dendritic cells from patients with systemic lupus erythematosus

BACKGROUND: Dendritic cells (DC), professional antigen presenting cells, are believed to play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). 1α, 25-dihydroxyvitamin D3 (VitD3), in addition to its effect on bone metabolism, has been increasingly recognised to have immunomodulatory effects. OBJECTIVE: To examine the effect of VitD3 on the differentiation, maturation, and activation of DCs in SLE patients. METHODS: CD14+ monocyte–derived DCs from SLE patients and age- and sex-matched controls were derived from growth medium cultured with IL-4, GM-CSF. Mature DCs were induced by addition of lipopolysaccharide and tumour necrosis factor-α in the presence or absence of VitD3 (1×10-10 M) and/or dexamethasone (1×10-6 M). The expression of CD1a, a DC marker and markers of maturation and co-stimulatory molecules such as CD80, CD86, CD40, HLA-DR and CD83 were examined by flow cytometry. After stimulation of DCs with CD40L for 24 hours, the production of pro-inflammatory cytokines including IL-12 and IL-6, were measured by ELISA kits. RESULTS: VitD3 suppresses differentiation of monocytes into DCs as showed by the decreased expression of CD1a (P<0.05). VitD3 inhibits the expression of maturation markers including CD86, CD40 and CD83 (P<0.05), but not CD80 and HLA-DR. This effect was more marked in SLE patients (n=14) than controls (n=9). In combination with dexamethasone, VitD3 displayed more potent immunosuppressive effect on DCs. Under the effect of VitD3, stimulated DCs produced less of IL-12 (3.1 vs 10.4 pg/mL, P=0.02) and IL-6 (216.0 vs 224.0 pg/mL, P=0.21) in SLE patients as well as controls (8.0 vs 36.6 μg/mL, P=0.01 for IL-12) and (380.7 vs 415.2 pg/mL, P=0.04 for IL-6). CONCLUSION: VitD3 is found to inhibit differentiation, maturation, and activation of DCs in vitro in both SLE patients and controls and may be considered as immunomodulatory agent in the treatment of SLE.published_or_final_versionThe 15th Medical Research Conference (15th MRC), Department of Medicine, University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16 n. 1, suppl. 1, p. 57, abstract no. 9

Electrolytic generation of ozone on antimony- And nickel-doped tin oxide electrode

In a recent report, ozone was produced with high efficiency in perchloric acid on an anode coated with antimony-doped tin oxide. We report here that high current efficiency can be enhanced if trace amounts of a second dopant, nickel, is present. The effect of composition of the coating in terms of Ni:Sb:Sn was carefully analyzed. The optimum Ni:Sb:Sn ratio, determined to be 1:8:500, was determined giving a corresponding ozone generation current efficiency of over 30% at room temperature. The highest current efficiency was observed at an optimum operating potential of 2.2 V vs Ag/AgCl. Electrolytic generation of ozone in perchloric acid, sulfuric acid, and phosphoric acid at different concentrations was also studied and compared. In 0.1 M H 2SO 4, the ozone concentration reached 34 mg/L and a current efficiency of 36.3% could be achieved. This is about the highest current efficiency ever reported for electrolytic generation of ozone in an aqueous medium at room temperature. © 2005 The Electrochemical Society. All rights reserved.published_or_final_versio

Electrochemical degradation of 4-chlorophenol at nickel-antimony doped tin oxide electrode

The effectiveness of a novel nickel-antimony doped tin oxide electrode for electrochemical degradation of organic pollutants was investigated using 4-chlorophenol (4-CP) as a model toxic organic. The experimental results demonstrate that the optimal Ni content was at Ni:Sn = 1:500 in atomic ratio in the precursor coating solution, whereas the Sb:Sn ratio was set at 8:500. Using the electrode prepared with the optimal Ni doping ratio for 4-CP degradation, the charge-based efficiencies were up to 89 μg C -1 for 4-CP destruction and 15 μg C -1 for TOC removal, which were considerably higher than the efficiencies observed for other electrodes. It is suggested that the enhancement of the electrode for electrochemical oxidation of organics could be attributed to the production of hydroxyl radicals in anodic water electrolysis. © 2006 Elsevier Ltd. All rights reserved.postprin

A novel polyphase multipole square-wave permanent magnet motor drive for electric vehicles

A novel high-power-density permanent magnet (PM) motor drive for electric vehicles (EVs) is proposed. The motor is a polyphase multipole square-wave PM motor, which can be classified as a kind of PM brushless DC motor. The distinct features of the proposed motor as compared to those of the conventional PM brushless DC motor are as follows. First, the multipole magnetic circuit arrangement enables the minimization of the magnetic yoke, resulting in the reduction of motor volume and weight. Second, the coil span is purposely designed to be equal to one slot pitch, thus saving the amount of copper used. Third, by using a fractional number of slots per pole per phase, the arrangement of the numbers of poles and slots is so unique that the magnetic force between the stator and the rotor at any rotating position is uniform, hence eliminating the cogging torque that usually occurs in PM motors. Finally, the motor can be controlled to operate at a constant torque region and a constant power region with field weakening, thus both high starting torque and high cruising speed can be achieved. Therefore, as the proposed motor drive possesses the distinct advantages of high power density, high efficiency, and superior dynamic performance, it is very suitable for EV applications. A prototype of a five-phase 22-pole 5 kW motor drive has been designed for an experimental EV.published_or_final_versio

Reactive oxygen species, endoplasmic reticulum stress and mitochondrial dysfunction: the link with cardiac arrhythmogenesis

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Suppression of nickel release in nickeltitanium alloys by plasma immersion ion implantation surface treatment: towards a new generation of "smart" orthopaedic implants

Summary form only given. Nickel-titanium shape memory alloys (NiTi) are potentially very useful in spinal deformity correction due to their super elastic properties and their ability to change shape with temperature. However, release of toxic nickel particulate debris remains a major concern. We have developed a novel method of altering the surface of the material to reduce nickel release by using plasma immersion ion implantation (PIII). This study compares the corrosion resistance and mechanical properties of PIII treated samples with untreated NiTi. NiTi discs containing 50.8% Ni were implanted with nitrogen using PIII technique. Their elemental depth profile, surface chemical composition, surface hardness and corrosion resistance were compared with untreated NiTi. The amount of Ni released into simulated body fluids after the accelerated corrosion tests were determined. The biocompatibility was assessed by culturing mouse osteoblasts expressing an enhanced green fluorescent protein on the surface of these materials. After PIII treatment, a layer of titanium nitride formed on the surface. Compared to untreated NiTi, the corrosion resistance is better by five times, and the surface hardness and elastic modulus are better by a factor of 2. The concentration of Ni in the simulated body fluid for the untreated sample was 30 ppm compared to undetectable levels in the PIII treated sample. There was no difference in the ability of cells to grow on either surface. PIII results in enhanced corrosion and wear resistance, and negligible Ni release. This technique will allow NiTi alloys to be safely implanted in the human body. A new generation of "smart" orthopaedic implants will likely result.published_or_final_versio

Clinical significance of CHD1L in hepatocellular carcinoma and therapeutic potentials of virus-mediated CHD1L depletion

Background: Hepatocellular carcinoma (HCC) is among the most lethal of human malignancies. It is difficult to detect early, has a high recurrence rate and is refractory to chemotherapies. Amplification of 1q21 is one of the most frequent genetic alterations in HCC. CHD1L is a newly identified oncogene responsible for 1q21 amplification. This study aims to investigate the role of CHD1L in predicting prognosis and chemotherapy response of patients with HCC, its chemoresistant mechanism and whether virus-mediated CHD1L silencing has therapeutic potentials for HCC treatment. Methods: The clinical significance of CHD1L in a cohort of 109 HCC cases including 50 cases who received transarterial chemoembolisation treatment was assessed by clinical correlation and Kaplan-Meier analyses. A CHD1L-overexpressing cell model was generated and the mechanism of chemoresistance involving CHD1L was investigated. An adenovirus-mediated silencing method was used to knockdown CHD1L, and its effects on tumorigenicity and chemoresistance were investigated in vivo and in vitro. Results: Overexpression of CHD1L was significantly associated with tumour microsatellite formation (p=0.045), advanced tumour stage (p=0.018), overall survival time (p=0.002), overall survival time of patients who received transarterial chemoembolisation treatment (p=0.028) and chemoresistance (p=0.020) in HCC. Interestingly, CHD1L could inhibit apoptosis induced by 5-fluorourail (5-FU) but not doxorubicin. The mechanistic study revealed that the involvement of the Nur77-mediated pathway in chemotherapeutic agent-induced apoptosis can dictate if CHD1L could confer resistance to chemotherapy. Furthermore, an adenoviral vector containing short hairpin RNAs against CHD1L (CHD1L-shRNAs) could suppress cell growth, clonogenicity and chemoresistance to 5-FU. An in vivo study found that CHD1L-shRNAs could inhibit xenograft tumour growth and increase the sensitivity of tumour cells to 5-FU in nude mice. Conclusions: This study highlighted for the first time the prognostic value of CHD1L in HCC and the potential application of virus-mediated CHD1L silencing in HCC treatment.published_or_final_versio

Indium tin oxide nanowires growth by dc sputtering

Indium tin oxide nanowires have been grown by dc sputtering on different substrates without the use of catalysts or oblique deposition. The nanowire length was of the order of several μm, while their diameter was ∼50- 100 nm. Small side branches on the nanowires were frequently observed. The nanowires were characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The growth mechanism of the nanowires is discussed. © Springer-Verlag 2011.published_or_final_versionSpringer Open Choice, 21 Feb 201

Role of AMPK signaling in mediating the anticancer effects of silibinin in esophageal squamous cell carcinoma

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