Homogeneous production of hydroperoxides concentrate has been simulated via multivariate calibration of yield data, obtained during an earlier study Naqvi and Khan Ind. Eng. Chem. Res. 2009, 48, 5642 ...made on the air oxidation of diluted gas oils in the presence of chemically generated redox couple Co(III)/Co(II). Principal component analysis has been applied to abstract dynamic hydroperoxides yield data that provides the basis for the simulation. A novel chemometric technique, inverse nonlinear principal component regression, has been introduced to simulate experimental yield profiles with exceptional accuracy (R 2 = 0.9841). Simulated yield profiles have then been subjected to Levenberg−Marquardt method in order to estimate the rate constants for formation and decomposition of hydroperoxides. These estimations have permitted the development of two reasonably accurate multivariate global models that relate the specific rates, for formation (R 2 = 0.8873) and decomposition (R 2 = 0.9504) of hydroperoxides, to process and composition variables. Construction of such models allows the specific rates to be optimized so that the reactor could be operated at an oil conversion (up to ≈5%) that is almost proportional to the yield of hydroperoxides ensuring selectivity ≈88%.
A number of metals are found in used lubricating oil. In this article, performance of solvent extraction followed by adsorption on magnesite has been studied for removal of metals from used oil. The ...suggested process is one of the efficient methods to remove not only sludge, but also the metals either present in the lubricating oil as additives or picked up by the oil during its working life. The re-refined oil has metal content comparable with base oil. In some cases, even lower metal content has been observed.
Intracranial Atherosclerotic Disease Khan, Maria; Naqvi, Imama; Bansari, Asha ...
Stroke Research and Treatment,
01/2011, Letnik:
2011
Journal Article
Recenzirano
Odprti dostop
Intracranial atherosclerotic disease (ICAD) is the most common proximate mechanism of ischemic stroke worldwide. Approximately half of those affected are Asians. For diagnosis of ICAD, intra-arterial ...angiography is the gold standard to identify extent of stenosis. However, noninvasive techniques including transcranial ultrasound and MRA are now emerging as reliable modalities to exclude moderate to severe (50%–99%) stenosis. Little is known about measures for primary prevention of the disease. In terms of secondary prevention of stroke due to intracranial atherosclerotic stenosis, aspirin continues to be the preferred antiplatelet agent although clopidogrel along with aspirin has shown promise in the acute phase. Among Asians, cilostazol has shown a favorable effect on symptomatic stenosis and is of benefit in terms of fewer bleeds. Moreover, aggressive risk factor management alone and in combination with dual antiplatelets been shown to be most effective in this group of patients. Interventional trials on intracranial atherosclerotic stenosis have so far only been carried out among Caucasians and have not yielded consistent results. Since the Asian population is known to be preferentially effected, focused trials need to be performed to establish treatment modalities that are most effective in this population.
A series of novel 4‐(3,3‐dimethylspiro{bicyclo2.2.1heptan‐2,5′‐isoxazoline‐2}‐3′‐yl)‐2‐phenyl‐2,3‐dihydro‐1H‐1,5‐benzodiazepines were synthesized. These molecules were screened in vitro for their ...antifungal and antibacterial activity, and none of the tested compounds showed promising antimicrobial or antifungal activity. J. Heterocyclic Chem., 2011.
To observe the safety of trans-jugular pressure-monitoring catheter insertion at a tertiary care teaching hospital in Rawalpindi, Pakistan.
The observational study was carried out at the Armed Forces ...Institute of Cardiology/National Institute of Heart Diseases, Rawalpindi, from January 1, 2004 to March 31, 2010. All patients electively scheduled to undergo cardiac surgery for congenital heart disease who had percutaneous trans-jugular pressure monitoring catheters inserted peri-operatively were included in the study. Dedicated Medtronic 3 Fr pressure monitoring catheters were passed through internal jugular vein using the modified Seldinger. The patients were followed up during the hospital stay for complications related to catheter insertion/removal. Data was analysed using SPSS version 15.
Of the 572 patients in the study, the catheters were ultimately positioned with the tips in the pulmonary artery in 447 (78.14%)patients, right ventricle 54 (9.44%) patients, left atrium in 52 (9.09%), and in both pulmonary artery and left atrium in 19 (3.32%) patients. Duration of pressure monitoring from all the chambers was 53 +/- 19 hours post-operatively. Transient and self-limiting atrial or ventricular ectopic beats were noticed in 163 (27.58%) patients during insertion. Catheter was found to be non-functional in 12 (2.03%) patients. Only one (0.16%) patient experienced recurrent tachyarrhythmia which required the withdrawal of catheter.
Insertion of trans-jugular pressure monitoring catheters during cardiac surgery for congenital heart disease is a safe and reliable technique.
CHRONIC HEPATITIS Akhund, Anwar Ali; Akhtar, Rehana; Naqvi, Syed Qaiser Husain ...
The professional medical journal,
06/2014, Letnik:
21, Številka:
3
Journal Article
Objective: To determine the correlation between HCV genotypes and serum ALTlevels in various patients of chronic hepatitis induced by hepatitis C virus, in our setup. Design: Aprospective study ...carried out from August 2006 to December 2009. Setting: Research MedicalCenter LUMHS Jamshoro, Pathology Department Peoples University of Medical & HealthSciences Nawabshah and Biotechnology Department University of Karachi. Patients: A total of344 HCV-PCR positive patients with different genotypes were evaluated 239 men and 105 womenwith ages between 18–55 years of age years were included in the study. Methodology: All thepatients went for ELISA test for the presence of HCV antibodies by ELISA kit of Biokit Spain, then a10.0 ml sample of blood was collected in a tube with separating gel, to obtain serum, which wasO stored at -80 C, for the determination of HCV RNA by RT- PCR (Real time cephid smart cycler) andfor determination of HCV-RNA genotypes by comparison in sizes of the products amplified by RTPCRusing HCV genotype- specific primers, then subjecting the product to electrophoresis byAnagen kit. 5.0 ml of blood was also collected in a tube with separating gel, to obtain serum,which was stored at room temperature for the determination alanine aminotransferase by usingUV enzymatic kinetic method. Results: when HCV genotypes were correlated with serum ALTlevels, 09 cases were found < 50 mg % and among these 06 cases were of genotype 1a, 02 caseswere of genotype 2a and one case of untyped. 55 cases shows serum ALT level between 50-100mg % and among this majority of cases belongs to untyped category. 209 cases shows serumALT level between 100-200 mg % and among this majority of cases belongs to genotype 3a. 71cases shows serum ALT level >200 mg % and among this majority of cases belongs to genotype3a. Conclusions: The data in the current study indicates the strong correlation between HCVgenotypes and serum ALT levels. The genotypes 3a, 3b and 2 were found associated with highserum ALT levels and the genotype 1 was found associated with low levels of serum ALT.
Inadvertent carotid artery puncture is a well‐known complication of internal jugular vein cannulation. A case of cerebral infarct subsequent to carotid artery puncture during internal jugular vein ...cannulation is reported.
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