Iron Oxide-Modified Carbon Electrode and Sulfate-Reducing Bacteria for Simultaneous Enhanced Electricity Generation and Tannery Wastewater Treatment.

The microbial fuel cell (MFC) is emerging as a potential technology for extracting energy from wastes/wastewater while they are treated. The major hindrance in MFC commercialization is lower power generation due to the sluggish transfer of electrons from the biocatalyst (bacteria) to the anode surface and inefficient microbial consortia for treating real complex wastewater. To overcome these concerns, a traditional carbon felt (CF) electrode modification was carried out by iron oxide (Fe3O4) nanoparticles via facile dip-and-dry methods, and mixed sulfate-reducing bacteria (SRBs) were utilized as efficient microbial consortia. In the modified CF electrode with SRBs, a considerable improvement in the bioelectrochemical operation was observed, where the power density (309 ± 13 mW/m2) was 1.86 times higher than bare CF with SRBs (166 ± 11 mW/m2), suggesting better bioelectrochemical performance of an SRB-enriched Fe3O4@CF anode in the MFC. This superior activity can be assigned to the lower charge transfer resistance, higher conductance, and increased number of catalytic sites of the Fe3O4@CF electrode. The SRB-enriched Fe3O4@CF anode also assists in enhancing MFC performance in terms of COD removal (>75%), indicating efficient biodegradability of tannery wastewater and a higher electron transfer rate from SRBs to the conductive anode. These findings demonstrate that a combination of the favorable properties of nanocomposites such as Fe3O4@CF anodes and efficient microbes for treating complex wastes can encourage new directions for renewable energy-related applications.

Catalytic Degradation of Benzene over Nanocatalysts containing Cerium and Manganese.

A Ce-Mn composite oxide possessing a rod-like morphology (with a fixed molar ratio of Ce/Mn=3:7) was synthesized through a hydrothermal method. Mn ions were doped into a CeO2 framework to replace Ce ions, thereby increasing the concentration of oxygen vacancies. The formation energies of O vacancies for the Ce-Mn composite oxide were calculated by applying density functional theory (DFT). The data showed that it was easier to form an O vacancy in the composite. The catalytic behavior of the Ce-Mn composite oxide for benzene degradation was researched in detail, which exhibited a higher activity than the pure phases. Based on this, the Ce-Mn composite oxide was chosen as a supporter to load PdO nanoparticles. The activity was enhanced further compared with that of the supporter alone (for the supporter, the reaction rate R214 °C=0.68×10-4 mol gcat-1 s-1 and apparent activation energy Ea=12.75 kJ mol-1; for the supporting catalyst, R214 °C=1.46×10-4 mol gcat-1 s-1, Ea=10.91 kJ mol-1). The corresponding catalytic mechanism was studied through in situ Raman and FTIR spectroscopy, which indicated that the process of benzene oxidation was related to different types of oxygen species existing at the surface of the catalysts.

Oral self screening among students of Dow University of Health Sciences.

OBJECTIVE: To determine the frequency of awareness of oral self screening in terms of clinical site and practice towards addiction among the students of health sciences according to low and high fees status. STUDY DESIGN: Qualitative study, KAP-study. PLACE AND DURATION OF STUDY: Dow University Campuses, from November 2008 to March 2009. METHODOLOGY: Twelve hundred and fifty undergraduate and graduate (male/female) medical students, filled oral self assessment questionnaire distributed among medical undergraduate and graduate students of the affiliated institutes of the Dow University of Health Sciences divided into those with low and high fees status according to annual tuition fees (less or more than 40,000 Rs). The students were mainly asked about their practices towards addiction include smoking and chewing tobacco and identification of sites effected. White /red striae, ulceration and/or epithelial erosions were detected under oral self examination for preneoplasia. SPSS-13.0 was used for statistical analysis. RESULTS: Low and high fees college showed contrasting results for addiction among students of DUHS. Addictions prevailed among high fees students group includes betel nut (7.7%), cigarette (3.2%), sheesha (3.1%), quid (3%), 1.1% gutka and 0.7% cigar (0.7%). Compared to betel nut (5%), quid (3.2%), sheesha and cigar (1.5%) each, cigarette (1.2%) and gutka (0.5%) for low fees group of students at DUHS. Intra oral lesions i.e. (ulcer, striae, erosions) were more frequent on gingiva (1.2%) in the low fees group, compared to 0.2% among high fees students group. Angle of mouth had 0.5% frequency for low and 0.7% for high fees group respectively. Tongue lesions were 1.7% for low and 1.0% for the high fees group students. Buccal mucosa had 1.0% and 1.2% lesions respectively for the low and high fees group. Palate lesions were 1.2% for low and 0.8% for high fees group. Floor of the mouth presented 0.7% lesions for high compared to 0.2% lesions for the low fees group students. CONCLUSION: Gingiva showed slightly higher prevalence of lesions for the low fees group students of DUHS. The patterns of addictions were also different according to the socioeconomic status.

Predictive accuracy of intrapartum cardiotocography in terms of fetal acid base status at birth.

OBJECTIVE: To find out the predictive value of intrapartum Cardiotocograph (CTG) in terms of fetal acid base status at birth in women undergoing emergency caesarean section for a suboptimal CTG trace. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: At the MCH Centre, Pakistan Institute of Medical Sciences, Islamabad, from June 2004 to July 2005. METHODOLOGY: All women undergoing emergency caesarean section for a suboptimal intrapartum CTG were recruited in the study. Immediately after the delivery of the baby a segment of umbilical cord was doubly clamped at a distance of 10 cm, and 2 ml of arterial cord blood was taken in a heparinized syringe for arterial blood gas indices analysis. All CTG tracings were reviewed using FIGO guidelines and compared for fetal arterial blood gas indices. RESULTS: Of the 57 patients who underwent cesarean section due to suboptimal CTG, 51 (89%) had suspicious trace while 6 (11%) had pathological trace. Positive predictive value of CTG was 18% for fetal hypoxia, 21% for fetal hypercarbia., 26% for fetal acidosis and 37% for base excess. Predictive value of suspicious trace for similar blood indices was 13%, 13%, 17% and 35% respectively. For pathological trace, predictive value was 50%, 83 %, 100% and 66% and respectively. CONCLUSION: Based on the results, it is concluded, that the suspicious CTG trace has low predictive value in terms of fetal acid base status at birth and needs to be complemented with other diagnostic modalities before undertaking any operative intervention. Pathological CTG on the other hand is highly predictive of fetal acidosis at birth warranting immediate intervention.