Experimentally and theoretically approaches for disperse red 60 dye adsorption on novel quaternary nanocomposites.

A comprehensive study that combined both experimental and computational experiments was performed to evaluate the usage of organo-metal oxide nanocomposite for the elimination of disperse red 60 dye (DR) from aqueous solutions. Chitosan was modified by Schiff base to form nanoneedles chitosan-4-chloroacetophenone derivative. The derivatives were then impregnated with CeO2-CuO-Fe2O3 or CeO2-CuO-Al2O3 metal oxides to prepare a novel quarternary organo-metal oxide nanocomposite. The novel nanocomposite, chitosan-4-chloroacetophenone/CeO2-CuO-Fe2O3 (CF) and chitosan-4-chloroacetophenone/CeO2-CuO-Al2O3 (CA) are cheap and effective nano adsorbents that can be used for the uptake of DR from aqueous solution. The CF and CA nano-composites were characterized using different techniques. Moreover, the effect of adsorption parameters (initial DR concentration, time of contact, pH, temperature, and adsorbent mass) as well as CA and CF reusability tests were performed. Langmuir adsorption isotherm and pseudo-second-order kinetics models were best fitted with the adsorption process. The maximum amount of DR adsorbed was 100 mg/g on CF and CA at pH 2 and 4, respectively with a physical spontaneous, and exothermic adsorption process. Monte Carlo (MC) simulation studies indicated the adsorption of DR molecule on the CF and CA surfaces following a parallel mode in most of all studied configurations, confirming the strong interactions between the DR and surfaces atoms of CF and CA. The molecular structure analysis of DR dye adsorbed on the surface of CF and CA indicated that the adsorption process related to Van der Waals dispersion force. Consequently, this helps to trap DR dye molecules on the surface of CF and CA (i.e., physical adsorption), which supports our experimental results.

Prevalence of latent TB among health care workers in four major tertiary care hospitals in Riyadh, Saudi Arabia.

BACKGROUND: Tuberculosis (TB) infection represents a global health problem and a great risk to Health Care Workers (HCWs). Identifying individuals, particularly HCWs with latent tuberculosis infection (LTBI) will support TB control through chemoprophylaxis and prevent cross-infection. OBJECTIVES: This study aimed to identify prevalence of Latent TB among a two-year new hires of HCWs in 4 major tertiary care hospitals in Riyadh, Saudi Arabia. MATERIAL AND METHODS: 2650 recently (2-years) hired HCWs were surveyed for latent TB using Tuberculin Skin Test (TST). Data was collected from January 2008 to December 2009. Induration due to TST equal to or more than 10 mm. within 48-72 hours was considered positive. The results of TST were correlated with other variables such as age group, gender, job category, country of origin. RESULTS: as an overall rate, 291(11%) out of 2650 were positive for TST, with the highest significant positive rates among physicians (14.9%) and nurses (12.9%) compared to students as a reference group. No statistically significant difference was detected between both sexes. The highest significant positive TST rates were found among HCWs in the age group of 50 years and older (32.6%) compared to 10-19 years age group as a reference group, and among HCWs coming from sub-Saharan countries (61.1%) compared to Saudi HCWs with the lowest positive rates (5%) as a reference group. CONCLUSION AND RECOMMENDATIONS: LTB is prevalent among newly hired HCWs in Riyadh tertiary hospitals. Standard programs for detection and treatment of LTB should be encouraged.

HIV/AIDS perceptions and risky behaviors in squatter areas in Cairo, Egypt.

UNLABELLED: The aim of this work was to assess HIV/AIDS perceptions and risky behaviors of adults living in squatter areas in order to take decisions about the relevant messages and health education methods that should be used to prevent HIV transmission in the studied communities. Two methods were used to collect data in this cross sectional study, focus group discussion and structured interview. The study was carried out in six squatter areas in Cairo, four of them located in west Cairo and two in east Cairo. RESULTS: 237 community members and community leaders shared in the study, 44.7% were males and 55.3% females, 64.1% were married and 34% single. Community members represented two-thirds of the sample while one-third were community leaders. Participants expressed strong eagerness to know more about HIV/AIDS. Poor knowledge and misconception about HIV/AIDS was remarkable. The study revealed several misconceptions regarding modes of transmission and preventive measures that could be used to protect oneself from HIV/AIDS. Heterosexual extramarital relationships and i.v. drug transmission were the HIV/AIDS risky behaviors considered to be prevalent in these communities. AIDS risky behaviors appear to be more prevalent in the four squatter areas in west Cairo than in the two squatter areas located in east Cairo. Adolescents were considered at high risk of contracting AIDS because of the risky behaviors they practice. Social non-acceptance of females who practice HIV/AIDS risky behaviors is much stronger than non-acceptance of males who practice the same risky behaviors. TV movies were the main source of information about HIV/AIDS. Parents played no role in providing adolescents with information about AIDS. The possible role of teachers in HIV/AIDS education is unclear because of the negative attitude of people towards teachers.

A study of fungal spore poupulations in the atmosphere of Kuwait.

The fungal air-spora of Kuwait was investigated using the Petri-dish trapping technique. During the period from 1st April, 1974 to 30th June, 1975, a total of 3685 colonies were recorded from 2% malt agar plates. Fifty-five genera and 116 species were identifed. Alternaria occupied the first place in the order of percentage incidence. being represented by 18.3% of the entire catch, followed by Aspergillus (17.1%), Penicillium (14%), Cladosporium (13.6%), Drechslera (13.3%), and Ulocladium (7.1%). The widest spectrum of species was displaced by Aspergillus (possessed 19 species) followed by Penicillium (17 species), Alternaria (6 species), Drechslera (5 species), and Ulocladium (4 species). The monthly total number of fungi showed marked seasonal periodicity with the greatest number of colonies occurring in March-April and November. The lowest counts were recorded in mid-summer (July) and mid-winter (January). Only 220 colonies and 17 species of thermophilous fungi were reported from plates incubated at 45 degrees C. The most common species were Aspergillus fumigatus and A. terreus.

Osmophilous fungi in the salt marshes of Kuwait.

During an investigation of the mycoflora inhabiting saline soils in Kuwait, special attention was focused on osmophilous fungi. A total of 101 species belonging to 46 genera were encountered from 40 soil samples collected from salt marshes using Czapek's agar supplemented with 40% sucrose. Soil samples were collected from different habitats at different distances from the water edge. Soils near to the water edge were poor in their fungal content, while those taken from areas covered by Juncus arabicus contained highest fungal populations. The recorded genera were classified as follows: 7 were of high frequency of occurrence, 8 moderate, 17 low, and 13 were rare. The order of dominance was Aspergillus, Alternaria, Penicillium, Cephalosporium, Fusarium, Stachybotrys, and Drechslera. Comparison between our results and those in other studies showed that there is no fungal flora characteristic of saline soils.