[en] Objective: To compare pregnancy-associated plasma protein-A (PAPP-A) levels in individuals with and without coronary artery disease (CAD). Study Design: Cross-sectional comparative study. Place and Duration of Study: Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, in collaboration with Armed Forces Institute of Cardiology (AFIC), from September 2008 to March 2010. Methodology: One hundred and twenty five (125) individuals both male and female were included in the study. Blood for PAPP-A and lipid profile was collected, just before angiography. On the basis of angiography, the individuals were divided into those with and without CAD. PAPP-A was analyzed by using Diagnostic System Laboratories (DSL) Enzyme Linked Immunosorbent Assay (ELISA) kit and reading was taken by ELISA reader. Lipid profile was determined on automated analyzers Selectra-2 and Vitros 5.1. Results: Amongst the 125 individuals, 41 individuals were without CAD whereas 84 individuals were having CAD. Mean PAPP-A levels were 0.74 +- 0.35 mIU/L in those without CAD whereas mean PAPP-A levels in those with CAD were 1.35 +- 0.57 mIU/L. The difference between the two groups was statistically significant (p < 0.001). A PAPP-A cut off level of 0.85 mIU/L had a sensitivity and specificity of 78% and 70% respectively for diagnosing atherosclerotic CAD. Conclusion: PAPP-A is a potentially relevant marker of the presence and extent of coronary atherosclerosis as its levels are elevated in CAD as compared to individuals without CAD. Pregnancy-associated plasma protein-A. (author)

[en] Nanofibre polyaniline (n-PANI) was synthesized by mini-emulsion polymerization technique between aniline monomer and ammonium persulfate as an oxidant using homogenizer. The synthesis was performed by optimizing mixing speed from 10,000 to 30,000 rpm and time reaction between 0.5 to 24 hours at fixed monomer to oxidant molar ratio 4:1. An attempt has been made to investigate on how the speed of homogenizer affects the size and conductivity of n-PANI. The formation of n-PANI chain was confirmed by Fourier transform infrared spectroscopy (FTIR). The X-ray diffraction (XRD) spectra revealed PANI crystalline nature. Hall effect measurement used indicated that the electrical conductivity of n-PANI is increased with homogenizer speed from 5.2 to 17.5 Scm-1. The morphological properties of n-PANI performed by scanning electron microscopy (SEM) show the decreasing size of n-PANI from 50-60 nm to 20-30 nm with the increment homogenizer speed. This study indicated the optimum speed parameter of homogenizer play a role in reducing the nanostructured size and thus, increasing the electrical conductivity of n-PANI. (paper)

[en] Solar collectors are technologies which using sunlight to collect heat energy. In this study, solar air collector-thermoelectric hybrid systemis designed and constructed. Performance testing is conducted in the lab. The size of this hybrid system is 97.5 × 59 × 12 cm. The manipulating factor is the mass flow rate which is fixed at 0.033, 0.0385, 0.044, 0.0495 and0.055 kg/s. The intensity of solar radiation is set at 700 W/m². Maximum temperature change (T_o -T_i) reaches 7.5 °C while maximum temperature change (T_back - T_hollow) reaches 16.7 °C. Maximum thermal efficiency of this hybrid system reaches 79.0% at the highest mass flow rate of 0.055 kg/s. The maximum electrical efficiency reaches 5.3% at the lowest mass flow rate of 0.033 kg/s. Maximum overall efficiency reaches 79% at the highest mass flow rate. The hybrid system has better thermal efficiency than a stand-alone solar air collector. Due to the increased overall efficiency, the proposed hybrid system is anticipated to promote wider application of thermoelectric hybrid system. (paper)

[en] Hexavalent chromium is carcinogenic and should be removed from industrial wastewater before discharged into water resources. Adsorption by using activated carbon from biomass is an economic and conventional way on removing the heavy metal ions from wastewater. In this research, activated carbon is synthesized from Jatropha curcas L. seed hull through chemical activation with ZnCl₂ and carbonized at 800 °C (JAC/ZnCl₂). The activated carbon has been characterized using FTIR, SEM-EDX, BET and CHNS-O analyzer. Adsorption isotherms have been analysed using Langmuir and Freundlich models to determine its removal mechanism. The maximum adsorption capacity of Cr (VI) metal ions onto JAC/ZnCl₂ activated carbon is 25.189 mg/g and following Langmuir isotherm model which is monolayer adsorption. (paper)