Adsorption performance of packed bed column for nitrate removal using PAN-oxime-nano Fe2O3

A continuous fixed bed study was carried out by using PAN-oxime-nano Fe2O3 as a sorbent for the removal of nitrate from aqueous solution. The effect of factors, such as flow rate (2, 5 and 7 mL/min) and bed depth (5, 10 and 15 cm) were studied. Data confirmed that the breakthrough curves were dependent on flow rate and bed depth. The adsoption capacities observed in diffent conditions of flow rates (2,5 and 7 mL/min) were 11.65, 24.38 and 25.89, respectively. Thomas model was applied to experimental data to predict the breakthrough curves using linear regression and to determine the characteristic parameters of the packed bed column. Bed depth/service time analysis (BDST) model was used to investigate the effect of bed depth on breakthrough curves. The results showed that Thomas model was suitable for the normal description of breakthrough curve at the experimental condition. The data were in good agreement with BDST model with R(2) > 0.98. Statistical analyses were performed on fluoride removal obtained from different flow rates using SPSS16 software by applying Kruskal- Wallis test. These findings suggested that PAN-oxime-nano Fe2O3 in the column structure presents a great potential in removal of nitrate from aqueous solutions.

Adsorption performance of packed bed column for nitrate removal using PAN-oxime-nano Fe2O3

A continuous fixed bed study was carried out by using PAN-oxime-nano Fe2O3 as a sorbent for the removal of nitrate from aqueous solution. The effect of factors, such as flow rate (2, 5 and 7 mL/min) and bed depth (5, 10 and 15 cm) were studied. Data confirmed that the breakthrough curves were dependent on flow rate and bed depth. The adsoption capacities observed in diffent conditions of flow rates (2,5 and 7 mL/min) were 11.65, 24.38 and 25.89, respectively. Thomas model was applied to experimental data to predict the breakthrough curves using linear regression and to determine the characteristic parameters of the packed bed column. Bed depth/service time analysis (BDST) model was used to investigate the effect of bed depth on breakthrough curves. The results showed that Thomas model was suitable for the normal description of breakthrough curve at the experimental condition. The data were in good agreement with BDST model with R(2) > 0.98. Statistical analyses were performed on fluoride removal obtained from different flow rates using SPSS16 software by applying Kruskal- Wallis test. These findings suggested that PAN-oxime-nano Fe2O3 in the column structure presents a great potential in removal of nitrate from aqueous solutions.

National guidelines for outbreak investigation: an evaluation study

This paper reports an independent epidemiological study to evaluate the validity of the results of an official investigation into an outbreak of gastroenteritis at a university campus in Yasuj, central-south Islamic Republic of Iran. The official report of the outbreak by the Department for Disease Control at the provincial health centre found only 65 cases over a 5-day period, all females, living in the student halls of residence. This contrasts with a questionnaire survey of 963 students at the same university, which found 395 students (192 males and 203 females), living in residences and at home, who reported at least 1 gastrointestinal symptom over a 12-week period. Within this period at least 2 outbreaks occurred. Such a large discrepancy between the official report and the current study suggests that the health services and the public may have been misled about the proper response to the outbreak.

Multiple Imputation to Deal with Missing Clinical Data in Rheumatologic Surveys: an Application in the WHO-ILAR COPCORD Study in Iran

BACKGROUND

The aim of the article is demonstrating an application of multiple imputation (MI) for handling missing clinical data in the setting of rheumatologic surveys using data derived from 10291 people participating in the first phase of the Community Oriented Program for Control of Rheumatic Disorders (COPCORD) in Iran.

METHODS

Five data subsets were produced from the original data set. Certain demographics were selected as complete variables. In each subset, we created a univariate pattern of missingness for knee osteoarthritis status as the outcome variable (disease) using different mechanisms and percentages. The crude disease proportion and its standard error were estimated separately for each complete data set to be used as true (baseline) values for percent bias calculation. The parameters of interest were also estimated for each incomplete data subset using two approaches to deal with missing data including complete case analysis (CCA) and MI with various imputation numbers. The two approaches were compared using appropriate analysis of variance.

RESULTS

With CCA, percent bias associated with missing data was 8.67 (95% CI: 7.81-9.53) for the proportion and 13.67 (95% CI: 12.60-14.74) for the standard error. However, they were 6.42 (95% CI: 5.56-7.29) and 10.04 (95% CI: 8.97-11.11), respectively using the MI method (M=15). Percent bias in estimating disease proportion and its standard error was significantly lower in missing data analysis using MI compared with CCA (P< 0.05).

CONCLUSION

To estimate the prevalence of rheumatic disorders such as knee osteoarthritis, applying MI using available demographics is superior to CCA.

Saffron in the treatment of patients with mild to moderate Alzheimer's disease: a 16-week, randomized and placebo-controlled trial

WHAT IS KNOWN

Herbal medicines have been used in the treatment of behavioural and psychological symptoms of dementia but with variable response. Crocus sativus (saffron) may inhibit the aggregation and deposition of amyloid β in the human brain and may therefore be useful in Alzheimer's disease (AD).

OBJECTIVE

The goal of this study was to assess the efficacy of saffron in the treatment of mild to moderate AD.

METHODS

Forty-six patients with probable AD were screened for a 16-week, double-blind study of parallel groups of patients with mild to moderate AD. The psychometric measures, which included AD assessment scale-cognitive subscale (ADAS-cog), and clinical dementia rating scale-sums of boxes, were performed to monitor the global cognitive and clinical profiles of the patients. Patients were randomly assigned to receive capsule saffron 30 mg/day (15 mg twice per day) (Group A) or capsule placebo (two capsules per day) for a 16-week study.

RESULTS

After 16 weeks, saffron produced a significantly better outcome on cognitive function than placebo (ADAS-cog: F=4·12, d.f.=1, P=0·04; CDR: F=4·12, d.f.=1, P=0·04). There were no significant differences in the two groups in terms of observed adverse events.

WHAT IS NEW AND CONCLUSION

This double-blind, placebo-controlled study suggests that at least in the short-term, saffron is both safe and effective in mild to moderate AD. Larger confirmatory randomized controlled trials are called for.

Ionically cross-linked carrageenan-alginate hydrogel beads

Hydrogel beads based on the carbohydrate biopolymers kappa-carrageenan and sodium alginate were newly prepared. Both classical and experimental design (Taguchi) methods were used to obtain the optimum conditions for the full-polysaccharide hydrogel preparation. The carrageenan-alginate (Caralgi) beads exhibited a surface morphology smoother than that of the one-polysaccharide network beads. Infrared spectroscopy and DSC/TGA thermal methods were used to study the chemical structure and thermal properties of the beads. The carrageenan parts appreciably enhanced thermostability of the networks. The fully carbohydrate-based hydrogel beads are expected to be biologically compatible and degradable. They are being considered as new carriers for drug loading and controlled delivery systems.