Recovery of cellulases by adsorption/desorption using cation exchange resins

Cellulases from Trichoderma reesei were recovered by adsorption in sodium acetate buffer at lower pH using cation exchange resins followed by desorption at higher pH. The weakly acidic ion exchange resin WK10 was found to be the best among the six resins tested in terms of the enzyme activity recovery. The optimal pH values for the adsorption and desorption were 4.0 and 8.0, respectively, and the optimal adsorption and desorption times were both 5 h. Almost 100% of the initial cellulase activity was recovered under the optimal conditions with the supplement of β-glucosidase, which was unable to be efficiently recovered due to its strong adsorption (95.7%) but poor desorption (1.9%).     

A review of childhood and adolescent obesity interventions

Obesity is one of the largest health problems facing Americans. Figures produced by the National Center for Health Statistics show that in 1999-2002, 15.8% of 6-11-year-olds were overweight as were 16.1% of adolescents aged 12-19. Some have proposed that interventions in childhood may be the best place to focus efforts to reduce the growing obesity epidemic. This paper examines several of the popular intervention strategies that have been proposed for youth and assesses the potential of these interventions for meaningful public health impacts. Findings show that most childhood obesity interventions completed to date produced only meager results, creating need for more well-designed studies that are tailored to the needs of specific age, ethnic and economic groups.     

Novel antitumor 2-cyanoaziridine-1-carboxamides

A set of 20 2-cyanoaziridine-1-carboxamides was synthesized from 2-cyanoaziridine and appropriate isocyanates. These compounds were active against a variety of solid and hematological tumor cells in culture, including strains resistant to doxorubicin and mitoxantrone. Their potencies in these assays correlated with the lipophilicity of substituents. The N-phenyl derivative was more potent and equally effective to imexon, a cyclized 2-cyanoaziridine-1-carboxamide of clinical interest, against cloned fresh human tumors.     

Intrusion Detection System for Wireless Sensor Networks Using Danger Theory Immune-Inspired Techniques

An IDS framework inspired in the Human Immune System to be applied in the wireless sensor network context is proposed. It uses an improved decentralized and customized version of the Dendritic Cell Algorithm, which allows nodes to monitor their neighborhood and collaborate to identify an intruder. The work was implemented and tested both in simulation and in real sensor platform scenarios, comparing them to each other and was also compared to a Negative Selection Theory implementation in order to demonstrate its efficiency in detecting a denial-of-sleep attack and in energy consumption. Results demonstrated the success of the proposal.     

Patients' experiences of patient-controlled analgesia

We examined patients' experiences of patient-controlled analgesia by the use of semistructured interviews in 26 patients shortly after discontinuation of the device. The options expressed by the patients were examined qualitatively to identify recurring themes in their experience of patient-controlled analgesia. The areas of interest were analgesia, factors influencing whether the patient pressed the button or not, whether they felt in control and side effects. Negative as well as the expected positive evaluations were found. The negative evaluations reflected problems with nausea and vomiting and inadequate analgesia. No clear strategy for pressing, or not pressing, the button emerged and the principle of control by the patient over their pain relief was not considered important.     

The risk of acquiring Q fever on farms: a seroepidemiological study

OBJECTIVES: To determine the occupational risk of Q fever. DESIGN: Cohort study. SETTING: Community: five English local authority districts. SUBJECTS AND METHODS: Prevalence and incidence of immunoglobulin G (IgG) specific antibody to Coxiella burnetii phase II antigen was measured in a representative (study) cohort of farm workers in the United Kingdom, and detailed exposure data were collected. Also seroprevalence of Q fever in a (control) cohort of police and emergency service personnel was measured. RESULTS: Prevalence was significantly (P < 0.01) higher in the study cohort (105/385 v 43/395). During the first 12 month period after enrollment no seroconversions were found (upper 95% confidence limit: 1318/100,000/year). During the second 12 month period after enrollment two seroconversions were found, equalling an incidence of 813/100,000/year (95% confidence interval (95% CI) 98-2937/100,000/year). No association was found between seroprevalence and age. In the study cohort, extent of total contact with farm animals seemed more important than exposure to any specific animal: full time employees were more than four times more likely to be antibody positive than part time employees (P < 0.05). Exposure to cattle, but not sheep, goats, cats, raw milk, and hay (all reported sources of Q fever) was associated with being positive to Coxiella burnetii IgG by univariate analysis but this association was not independent of total farm animal contact. CONCLUSIONS: The risk of Q fever on livestock farms is related to contact with the farm environment rather than any specific animal exposure. The absence of an increasing prevalence with age suggests that exposure may occur as clusters in space and time (outbreaks).     

Independent design of robust partially decentralized controllers

An independent design method for robust partially decentralized controllers is developed. In the proposed design method, the partially decentralized control system is first expanded to the nonsquare decentralized structure. Using the Internal Model Control parametrization, the independent design procedure for robust nonsquare decentralized controllers can then be applied directly to the expanded system. Two examples, including a nonlinear stirred mixing tank, are used to illustrate the developed design method and a comparison to a decentralized controller is made.     

Electroosmotic flow in irregular shape microchannels

The electrokinetic flow through star-point family microchannels is studied. Mathematical solutions using a semi-analytical approach are employed to model the steady, fully developed electroosmotic flow in the closed-end star point family microchannels. The model can be extended to other irregular shape channels. The effects of sharp corners, electrolyte concentration and packed capillary radius, R₀ are analyzed. Comparisons of the flow characteristics and induced pressure gradient inside and outside of the packed capillaries are presented.