Petrochemical wastewater odor treatment by biofiltration.

The treatment of odorous pollutants by microorganisms on packed waste straw and cortex was investigated at the wastewater treatment plant of the Shanghai petrochemical factory. The removal efficiency of H(2)S, NH(3) and VOCs (volatile organic compounds) reached 98%, 91% and 90%, respectively after operation for one month at an empty bed retention time (EBRT) of 120s. The heterotrophic bacteria were found to be the dominant microorganism in the biofilter, while fungi and actinomycetes were also present. The bacteria were mostly identified as the members of the genus Bacillus (62.5% of cultured bacteria). The single strand conformation polymorphism (SSCP) results revealed that the genus Bacillus and Pseudomonas were the predominant bacteria. The microbial diversity gradually increased as the treatment progressed, which indicated that the microbial community in the biofilter became more stable upon pollutant removal. The scanning electron microscopy (SEM) was performed to evaluate the microorganism growth on the media. It was found that the waste straw and cortex were suitable for microorganism attachment and growth, and may have potential application in odor treatment.

A Ufd2/D4Cole1e chimeric protein and overexpression of Rbp7 in the slow Wallerian degeneration (WldS) mouse.

Exons of three genes were identified within the 85-kilobase tandem triplication unit of the slow Wallerian degeneration mutant mouse, C57BL/Wld(S). Ubiquitin fusion degradation protein 2 (Ufd2) and a previously undescribed gene, D4Cole1e, span the proximal and distal boundaries of the repeat unit, respectively. They have the same chromosomal orientation and form a chimeric gene when brought together at the boundaries between adjacent repeat units in Wld(S). The chimeric mRNA is abundantly expressed in the nervous system and encodes an in-frame fusion protein consisting of the N-terminal 70 amino acids of Ufd2, the C-terminal 302 amino acids of D4Cole1e, and an aspartic acid formed at the junction. Antisera raised against synthetic peptides detect the expected 43-kDa protein specifically in Wld(S) brain. This expression pattern, together with the previously established role of ubiquitination in axon degeneration, makes the chimeric gene a promising candidate for Wld. The third gene altered by the triplication, Rbp7, is a novel member of the cellular retinoid-binding protein family and is highly expressed in white adipose tissue and mammary gland. The whole gene lies within the repeat unit leading to overexpression of the normal transcript in Wld(S) mice. However, it is undetectable on Northern blots of Wld(S) brain and seems unlikely to be the Wld gene. These data reveal both a candidate gene for Wld and the potential of the Wld(S) mutant for studies of ubiquitin and retinoid metabolism.

The effect of ketamine on clinical endpoints of hypnosis and EEG variables during propofol infusion.

BACKGROUND: We studied the effect of variable doses of ketamine on the endpoints of hypnosis, e.g., unresponsiveness to verbal commands (UVC), loss of eyelash reflex (LER), and inhibition of body movement response with or without sneezing to nasal membrane stimulation (INBMR), and processed EEG variables, e.g., bispectral index (BIS), 95% spectral edge frequency (SEF) and median frequency (MF) during propofol infusion. METHODS: Forty-eight patients received either propofol infusion, 30 mg.kg-1.h-1 (Group P; n = 12) or ketamine bolus, 0.25, 0.5 or 0.75 mg i.v., followed by propofol infusion, 30 mg.kg-1.h-1 + variable dose ketamine infusion, 0.25, 0.5 or 0.75 mg.kg-1.h-1 (Groups PK0.25, PK0.5 and PK0.75; n = 12 each) until UVC, LER and INBMR. BIS, 95% SEF and MF values were monitored and recorded at the endpoints of hypnosis. Propofol and ketamine concentrations were measured at INBMR. RESULTS: Propofol infusion, 30 mg.kg-1.h-1, induced UVC, LER and INBMR at BIS: 65 +/- 2, 63 +/- 9 and 33 +/- 7; 95% SEF: 17 +/- 3, 17 +/- 4 and 14 +/- 3; and MF values of 5 +/- 2, 5 +/- 3 and 3 +/- 2, respectively. With adjunctive ketamine (Groups PK0.5 and PK0.75), the hypnotic endpoints were achieved at higher BIS and 95% SEF values and lower propofol doses and concentrations as compared to Groups P and PK0.25 (9.9 +/- 5.8 and 9.4 +/- 3.4 vs. 13.4 +/- 4.5 and 14 +/- 5.8 micrograms.ml-1). CONCLUSIONS: Our results suggest additive interaction between propofol and ketamine (Groups PK0.5 and PK0.75) for achieving the hypnotic endpoints; however, ketamine did not depress the EEG variables in proportion to its hypnotic effect. The paradoxically higher BIS and 95% SEF values at the hypnotic endpoints may be due to lower propofol concentrations and/or no effect of ketamine on the EEG variables.