Combined promoting effects of low-Pd-containing and Cu-doped LaCoO3 perovskite supported on cordierite for the catalytic combustion of benzene.

The catalytic activities for benzene oxidation and resistance to SO2 poisoning were tested for a series of Pd/La-Cu-Co-O/cordierite catalysts, which were prepared using a multiple-step impregnation method. The XRD, SEM, and IR characterization techniques were performed to investigate the relationship between the catalytic performance and its physicochemical properties. When Pd/La-Cu-Co-O/cordierite catalysts with Pd loadings of 0.06 and 0.08 % were prepared at a calcination temperature of 500 °C for 5 h, they exhibited similar catalytic activity and sulfur resistance. When the concentration of benzene was 1500 ppm and the GHSV was 20000 h(-1), the benzene conversion was above 95 % at a reaction temperature of 350 °C in SO2 existing at 100 ppm. These results were mainly attributed to the cooperation between La-Cu-Co-O perovskite and the noble metal Pd. Specifically, the addition of copper can strengthen the catalytic activity of La-Co-O/cordierite catalysts by decreasing the crystalline size of the active ingredients. A moderate Pd addition can drastically improve the sulfur resistance and further improve the catalytic activity of the La-Cu-Co-O/cordierite catalyst.

High NH(4)(+)-N concentration wastewater treatment by shortcut nitrification-denitrification using a system of A/O inner loop fluidized bed biofilm reactors.

In this experiment, a rapid mass-transfer inner loop fluidized bed biofilm reactor (ILFBBR) was employed to treat synthetic high ammonia nitrogen-containing (NH(4)(+)-N) wastewater by shortcut nitrification-denitrification. The reactor operation was stable after a short start-up period. Ammonia oxidizing bacteria (AOB) were predominant and 65% nitrite (NO(2)(-)-N/NO(x)(-)-N) levels were achieved. During the nitrification-denitrification period, the removal rates of NH(4)(+)-N and total nitrogen (TN) reached 94 and 82%, respectively. From the material balance, it was indicated that 87% of NH(4)(+)-N was removed by shortcut nitrification. The features of ILFBBR and the benefits of shortcut nitrification were combined in this experiment, and showed an excellent removal of NH(4)(+)-N from high-concentration NH(4)(+)-N wastewater.

A cascade of anoxic and oxic fluidized bed biofilm reactors for treatment of synthetic municipal wastewater.

In this study, a cascade of anoxic and oxic fluidized bed biofilm reactors system was carried out to treat synthetic municipal wastewater. The parameters of the influent flow rates and C/N ratios were discussed. System performance was acceptable for chemical oxygen demand (COD), ammonia, and total nitrogen removal. A decrease of ammonia and total nitrogen removal efficiencies, however, was observed when the influent flow rates increased to 5.04 and 6.12 1 h(-1). Total nitrogen removal decreased at the influent C/N ratio of 3:1. The measured ratios of COD reduction in the anoxic column to nitrogen removal through nitrification-denitrification were 3.7, 3.5, 3.3, and 3.1 g COD/g(-1) N on average when the influent C/N ratios changed from 6:1 to 3:1. The observed sludge yield (Yobs) was 0.169 g VSS g COD(-1) because of perfect denitrification in the anoxic column and the relatively long solids retention time.

Deregulation of EIF4E: a novel mechanism for autism.

BACKGROUND: Autism is a common childhood onset neurodevelopmental disorder, characterised by severe and sustained impairment of social interaction and social communication, as well as a notably restricted repertoire of activities and interests. Its aetiology is multifactorial with a strong genetic basis. EIF4E is the rate limiting component of eukaryotic translation initiation, and plays a key role in learning and memory through its control of translation within the synapse. EIF4E mediated translation is the final common process modulated by the mammalian target of rapamycin (mTOR), PTEN and fragile X mental retardation protein (FMRP) pathways, which are implicated in autism. Linkage of autism to the EIF4E region on chromosome 4q has been found in genome wide linkage studies. METHODS AND RESULTS: The authors present evidence that directly implicates EIF4E in autism. In a boy with classic autism, the authors observed a de novo chromosome translocation between 4q and 5q and mapped the breakpoint site to within a proposed alternative transcript of EIF4E. They then screened 120 autism families for mutations and found two unrelated families where in each case both autistic siblings and one of the parents harboured the same single nucleotide insertion at position -25 in the basal element of the EIF4E promoter. Electrophoretic mobility shift assays and reporter gene studies show that this mutation enhances binding of a nuclear factor and EIF4E promoter activity. CONCLUSIONS: These observations implicate EIF4E, and more specifically control of EIF4E activity, directly in autism. The findings raise the exciting possibility that pharmacological manipulation of EIF4E may provide therapeutic benefit for those with autism caused by disturbance of the converging pathways controlling EIF4E activity.

Effects of yeast culture and fibrolytic enzyme supplementation on in vitro fermentation characteristics of low-quality cereal straws.

The effects of yeast culture and fibrolytic enzyme preparation (containing cellulase and xylanase) on in vitro fermentation characteristics of rice straw, wheat straw, maize stover, and maize stover silage were examined using an in vitro gas production technique. Four levels of yeast culture and fibrolytic enzyme supplements (0, 2.5, 5.0, and 7.5 g/kg of straw DM, respectively) were tested in a 4 x 4 factorial arrangement. Supplementation of yeast culture increased the cumulative gas production, theoretical maximum of gas production, rate of gas production, IVDMD, and in vitro OM disappearance (IVOMD), and decreased the lag time for each type of straw. Fibrolytic enzyme supplementation tended to increase cumulative gas production, theoretical maximum of gas production, and rate of gas production; prolonged lag time of gas production; and enhanced IVDMD and IVOMD for 4 types of cereal straws, with the significance of this effect being dependent on the level of supplemented enzymes. There were significant interactions between fibrolytic enzymes and yeast on all in vitro gas production parameters, IVDMD, and IVOMD of each type of straw. The outcome of this research indicated that the application of fibrolytic enzyme preparation and yeast culture could improve in vitro gas production fermentation of cereal straws.

Prediction of metal precipitates in tannery sludge leachate based on thermodynamic calculations.

Thermodynamic calculations were performed in order to predict the formation of metal precipitates during the tannery sludge leaching. Gibbs free energy deltaG=RTln(Qc/Kc) of precipitation reaction was used to examine the formation of precipitates during the leaching process. The values of activity equilibrium constant (Ka) of various precipitation reactions were adopted from the literature. The Ka values were corrected to obtain the corresponding values of concentration product (Qc) and concentration equilibrium constant (Kc) using the activity coefficients (gamma) of the ions. The activity coefficients (gamma) of the ions was calculated using Davies equation Lngammai=-1.172Zi2((I0.5/(1+I0.5))-0.3I) (aqueous solution, 25 degrees C, 1 atm, I>0.3 mol x l(-1)). The values of ionic strength (I) at different sludge solids concentration and leaching pH were obtained by measuring the concentration of all ionic species in the leachate. The thermodynamic calculations indicated that the possible metal precipitates formed during the leaching process were (am)Cr(OH)3, (am)CrPO4, (am)Fe(OH)3, alpha-FeOOH(goethite), FePO4.2H2O, (am)AIPO4-2H2O, CaSO4.2H2O(gypsum). The solubility of these precipitates was found to decrease with the increase in the ionic strength (or sludge solids concentration). The results of computations were supported by the experimental observations.

[Detection of brain vascular diseases with CT angiography].

OBJECTIVE: To identify the diagnostic effect of spiral CT in brain vascular diseases. METHODS: Sixty four patients underwent CT angiography, including 22 patients with subarachnoid hemorrhage (SAH), 6 patients with oculomotor nerve paralysis, 5 patients with brain substance hemorrhage, 6 patients with arteriovenous malformation (AVM), 4 patients with mass or aneurysm, 5 patients with brain infarction, 16 patients with epilepsy or headache and dizzy. 8 cases also underwent digital subtraction angiography (DSA), 4 cases were performed operation in 64 cases. RESULTS: Spiral computed tomography angiography (SCTA) was all succeeded in 64 cases. 26 aneurysms and 8 AVMs were found by SCTA; in 6 of 8 cases of AVMs, their supply arteries and drainage veins were clearly displayed; SCTAs of 5 cases with substance hemorrhage were normal; in 1 of 5 cases with cerebral hemisphere infarction, its internal carotid obstruction was demonstrated by SCTA; the results of 12 SCTAs were identical with the results of their DSA or operation. CONCLUSION: SCTA is a useful non-invasive inspection method for detecting brain vascular diseases such as aneurysms and AVMs.

Extraction of Cr(III) and other metals from tannery sludge by mineral acids.

A comprehensive investigation on the extraction conditions of Cr(III) and other metals from tannery sludge using mineral acids was performed. The effect of various factors (the extraction time, the type of mineral acid, the consumption of acid, pH, sludge solids concentration, temperature, and the type of sludge) on the leaching yield of metals was studied. The results indicate that the metal extraction time for most of the metals was 2h at 25 degrees C. The most suitable acid for Cr(III) extraction was sulphuric acid. A relationship for the acid requirement to adjust different sludge pH at varying sludge solids concentration was established. The leaching yield of chromium varied with sludge pH and the suitable pH for Cr(III) extraction was between 2.0 to 3.0. The optimum sludge solids concentration for Cr(III) extraction was 78.5 g x l(-1). The leaching yield of Cr(III) decreased with the increased temperature. The type of sludge (wet or dry) has no effect on the leaching yield of Cr(III) The metal adsorption and bonding on the insoluble organic colloid matter as well as the formation of metal precipitates may be two possible reasons for the decreased extraction yield of metals with increased solids concentration.

[Study on the optimal conditions in simultaneous reaction and separation for L-malic acid production].

Based on the principle of coupling reaction and separation process, free cells containing fumarase were used for producing L-malic acid. The calcium fumarate was used as substrate to produce calcium malate directly. This new method was more advantageous than the traditional immobilized cells conversion system in aspects such as simple equipment and operation, high conversion efficiency and the yield of product. The results showed that at reaction temperature 40 degrees C, pH7.0-7.5, reaction time 20-28 h, the conversion efficiency was up to 99.9% and about 3.2 kg calcium fumarate was converted to calcium malate per liter enzyme suspension. Also, L-malic acid produced in free fumarase system satisfied USP criterion, the residual fumaric acid was less than 0.1% and the cost was approximately to that of DL-malic acid produced by chemical synthesis.

[The study of the developmental potential of early embryonic cells of rabbit].

The developmental potential of rabbit embryonic cells was studied through making chimera by separate introduction of inner cell mass from 96-h-old p. c., 120-h-old p. c., and 144-h-old p. c. of grey rabbits into 96-h-old p. c. blastocysts of New Zealand white rabbits. A total of five overt chimeras were obtained including two fertile males, two fertile females and one sterile male, from the ICM cells of 96-h-old and 120-h-old embryos but none was obtained from 144-h-old cells. Histological examination of the gonad showed that the sterile chimera derived from 120-h-old ICM cells with an ovotestis on both sides. Follicles and seminiferous tubules developed in the cortex and medulla of the gonad, respectively. Neither of them developed into functional germ cells. Analysis of karyotypes of peripheral blood showed that both XX and XY coexisted in lymphocytes. These results indicated that the sterile male chimera was a XX/XY sex chimera derived from ICM cells of donor and recipients with different sex, so as to the chimera with XX and XY genotypic cells. From the results mentioned above we may conclude that the ICM cells at 120-h-old p. c. are still pluripotential, they can not only participate in development into somatic components but also develop into germ cells. The potential of 144-h-old p. c. ICM cells seems to be rather restricted.