Synthesis of Long-Chain β-Lactones and Their Antibacterial Activities against Pathogenic Mycobacteria

In the quest for new antibacterial agents, a series of novel long- and medium-chain mono- and disubstituted β-lactones was developed. Their activity against three pathogenic mycobacteria—M. abscessus, M. marinum, and M. tuberculosis—was assessed by the resazurin microtiter assay (REMA). Among the 16 β-lactones synthesized, only 3-hexadecyloxetan-2-one (VM005) exhibited promising activity against M. abscessus, whereas most of the β-lactones showed interesting activities against M. marinum, similar to that of the classical antibiotic, isoniazid. Regarding M. tuberculosis, six compounds were found to be active against this mycobacterium, with β-lactone VM008 [trans-(Z)-3-(hexadec-7-en-1-yl)-4-propyloxetan-2-one] being the best growth inhibitor. The promising antibacterial activities of the best compounds in this series suggest that these molecules may serve as leads for the development of much more efficient antimycobacterial agents.     

Management gaps analysis: a case study of groundwater resource management in New Zealand

The primary objective of this project is to identify gaps, whether real or perceived, that hinder effective groundwater management in New Zealand. These gaps show as gaps in information, gaps in implementation, gaps in technological and management tools, and gaps in understanding of fundamental processes. The secondary objective is to propose a management strategy to close the identified gaps. Several methods are used to meet these objectives: surveys distributed to selected staff in each regional council; the review of various written reports; the analysis of land-use databases; and private consultation within each regional council. Results show that groundwater management in New Zealand is generally reactionary with the main gaps being in strategic planning and national guidelines. Most gaps appear to be predominantly information and implementation issues. In some cases there are gaps in the understanding of fundamental processes within an aquifer system, including the long-term effects of land-use on groundwater quality. An adaptive management approach is suggested as a means of closing these gaps.     

SIMULATION STUDIES OF THE REMOVAL OF WATER FROM ETHANOL BY A CATALYTIC DISTILLATION PROCESS

A new approach based on catalytic distillation (CD) technology was proposed to remove water from ethanol. Isobutylene was introduced to react with water in the CD column. The commercial software simulation tool Aspen Plus was used to investigate the effects of key design factors such as operating pressure and temperature, reactant ratios, reflux and distillate to feed ratios, number of separation and reaction stages, and feed and reaction zone location. It was found that the CD technology offers potential advantages of reduced energy consumption and reduced capital cost over traditional approaches for the removal of water from ethanol.     

Transformations of ileo-rectal anastomosis into ileo-anal anastomosis in hemorrhagic rectocolitis. Indications and results

In order to precise the indications and results of this procedure, we assessed 11 cases of transformation of ileorectal anastomosis (IRA) to ileal pouch-anal anastomosis (IPAA) in ulcerative colitis (UC). These 5 men and 6 women had undergone IRA at a mean age of 31 years, 33 months after the diagnosis of UC (range 3-120). Four of these IRA, excluded by an ileostomy, had never been in function: the cause was severe persistent proctitis in 2 cases and anastomotic leakage and peritonitis in 2 cases. The other 7 IRA had been in function during a mean period of 25 months (range 6-45) and were reoperated because of anal sepsis (1 case), low rectal stenosis (1 case), disabling proctitis (4 cases) and rectal dysplasia (1 case). No patient had specific pathologic signs of Crohn's disease. The 11 IPAA were complicated by pelvic sepsis in 3 cases; surgical drainage succeeded in 1 case, but the 2 others needed pouch excision and terminal ileostomy. The diagnosis of Crohn's disease was eventually made in these 2 patients. The 9 patients with functioning IPAA, at a mean follow-up of 40 months (range 12-60), had 5.2 stools per 24 h (range 2-12), 5 patients had no nocturnal stooling, and 6 had a perfect continence. One patient had disabling chronic pouchitis. In conclusion, proctectomy with IPAA is always feasible when a previous IRA for UC had failed or offers poor results, but should be rejected in case of anal involvement, as that may suggest Crohn's disease. This procedure is followed by similar functional results than after primary IPAA.     

Development and simulation studies of an unsteady state biofilter model for the treatment of cyclic air emissions of an α‐pinene gas stream

This paper describes the development and simulation of an unsteady state biofilter model used to predict dynamic behaviour of cyclically‐operated biofilters and compares it with experimental results obtained from three, parallel, bench‐scale biofilters treating both periodically fluctuating concentrations and constant concentrations of an α‐pinene‐laden gas stream. The dynamic model, using kinetic parameters estimated from the constant concentration biofilter, was able to predict the performance of cyclic biofilters operating at short cycle periods (ie, in the order of minutes and hours). Steady state kinetic data from a constant concentration biofilter can be used to predict unsteady state biofilter operation. At a 24 h cycle period, the dynamic model compared well with experimental results. For long cycle periods (ie, hours and days), removal efficiency decreased after periods of non‐loading: the longer the period of non‐loading, the poorer the biofilter's performance at the re‐commencement of pollutant loading. At longer time scales the model did not effectively predict transient behaviour, as adsorption and changes in kinetic parameters were not accounted for. Modelling results showed that similar biofiltration performance for the cyclic and constant concentration biofiltration of α‐pinene is expected for biofilters operating solely in the first order kinetics regime. Poorer performance for cyclic biofilters following Monod kinetics spanning the entire kinetics range is expected as the cycle amplitude increases. The most important parameters affecting the performance of a cyclically‐operated biofilter with short cycle periods are: amplitude of cyclic fluctuations, C_{g, max}/C_g, relative value of the half‐saturation constant in the Monod expression, K_s, and effective diffusivity of α‐pinene in the biofilm, D_e. Copyright © 2005 Society of Chemical Industry