[en] Objective: To study the spectrum of histopathological findings in live donor liver graft biopsies. Study Design: Case series. Place and Duration of Study:Histopathology Department, Shifa International Hospital, Islamabad, from January 2011 to March 2014. Methodology: The biopsies were received in formalin and routinely processed. The changes encountered were divided into three categories: (i) new-onset post liver transplantation (LT) complications (early and late), (ii) acute rejection and (iii) recurrence of original disease. Banff schema 1997 of rejection activity index (RAI), modified histological activity index (mHAI) and recent literature were utilized for evaluation. The results were finalized in the light of clinical details along with relevant laboratory investigations and radiological findings. Results: Seventy eight percutaneous hepatic graft biopsies of 59 patients were evaluated. Among them, findings noticed in descending order of frequencies were Acute Cellular Rejection (ACR) in 37 percentage (n=30), recurrent hepatitis C (HCV) in 22 percentage (n=18), cholestasis/ductular proliferation in 27 percentage (n=22), ischemic/reperfusion injury in 9.8 percentage (n=8) and drug-induced liver injury in 3.7 percentage (n=3). In the first six months post LT, ACR was the commonest cause of graft dysfunction, while recurrent HCV was noticed to be predominant reason after 6 months. Conclusion: In this study, ACR was the most frequent finding in graft biopsies, followed by recurrent HCV. However, in first six months, ACR is the commonest histopathological finding while recurrent HCV was more frequently documented after 6 months. (author)

[en] Development in the field of asymmetric catalysis is driven by the importance of stereochemically pure compounds in the field of pharmaceutical industry, agrochemicals and flavors. The unpredictable results given by new catalysts make the design of effective ones a long and costly work. Combinatorial asymmetric catalysis is the fastest and most efficient tools for finding best catalysts and it helps for many catalytic systems to be screened in a short period of time to decide about their effectiveness in synthesizing stereospicific products. This work describes rapid screening of chiral asymmetric oxazoline, imine, aminal and bisimine bidentate ligands and their in situ use for catalytic transfer hydrogenation of ketone in the presence of zinc. The ligands thus prepared in situ gave nearly same results with that of the purified version. The ligands which gave more than 70% ee with excellent conversions (<90%) were readily identified. Thus ligands with excellent results can be purified in bulk to save time and money. (author)

[en] In this era of technology, when every nation is striving hard to maintain their energy strategic channels intact and find the way to explore new frontier of renewable and sustainable energy resources, underground coal gasification (UCG) provides unique opportunity to meet the future energy need. Although this UCG tech is still under sanitization stage but still a number of countries adopting this technology. Specially country like Pakistan, where man - created energy crisis exist, a large reserve of Thar coal is blessing in disguise and UCG is way forward to utilize this for bright future of the country. This paper explores the UCG basic aspect ranging from prologue to global cohort in this field. The energy, economic and environmental demands of the 21 century appear to support a renewed and expanded role for commercial UCG development. (author)

[en] The drive to find alternative fuels to replace such hydrocarbons as diesel and petrol has resulted in an excess of different fuels-few of which are commercially available in large quantities. As fuels, by their very nature, must be combustible, the fire, explosion and explosion properties will need to be known. The use of biomass as a source of energy has been further improved in recent years and special interest has been paid to biomass gasification. Due to the increasing interest in biomass gasification, several studies have been proposed in order to explain and understand this complex process, and the design, simulation, optimization and process analysis of gasifiers have been carried out. This paper reviews several Biomass gasification studies. (author)

[en] Spontaneous pneumomediastinum with COVID pneumonia is a rare occurrence with or without accompanying subcutaneous emphysema or pneumothorax. The aim of this study was to establish relation of this complication to severity of lung disease and its clinical outcome. The study was conducted for a period of seven months from April to October 2020 in the CT Department of Armed Forces Institute of Radiology and Imaging (AFIRI), Rawalpindi, Pakistan. All COVID positive patients having spontaneous pneumomediastinum on high resolution CT (HRCT) chest were included (n=14). These patients were assessed for severity of lung disease as per CT severity score (CTSS), and were followed up for their clinical outcome. All patients with spontaneous pneumomediastinum had moderate to severe degree of COVID pneumonia; mortality in patients with pneumomediastinum was 50%; and was seen in those patients who had greater severity of lung disease as per the CTSS. (author)

[en] Objective: To determine the diagnostic accuracy of cerebrospinal fluid lactate level in confirmed cases of acute bacterial meningitis in children Methods: This cross sectional study was conducted in the Department of Paediatrics, King Edward Medical University/ Mayo Hospital, Lahore from January to December 2018. A total of 250 children, between two months - 12 years of age, of both the genders, with suspected acute bacterial meningitis were included by non-probability consecutive sampling. Each child was subjected to lumbar puncture for biochemistry, cytology, culture, and lactate level. CSF lactate level of 1.1-2.4 mmol/L was taken as normal, and >2.4 mmol/L was taken as cut off for acute bacterial meningitis. All collected data was entered and analyzed in SPSS version 22. A 2 x 2 table was made to calculate diagnostic accuracy, sensitivity, specificity, positive and negative predictive value for CSF Lactate. Results: The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CSF lactate taking CSF culture as gold standard was 100%, 60.61%, 17.27%, 100% and 63.6% respectively, with kappa of 0.19 and p value of 0.000. Conclusion: At a cut off value of 2.4 mmol/L, cerebrospinal fluid lactate level has a high diagnostic accuracy for acute bacterial meningitis. (author)

[en] Objective: To review all the patients of spinal dysraphism referred to our center over a three year period in order to identify the most typical neuro-radiological appearances on Magnetic Resonance Imaging. Study Design: Cross sectional study. Place and Duration of Study: Armed Forces Institute of Radiology and Imaging, Rawalpindi from Jan 2016 to Dec 2018. Methodology: MR spine reports of 144 patients of spinal dysraphism were retrospectively analyzed. Age, gender, indication for MRI, operative status, and neuro-radiological features (including site and type of lesion) were recorded for these patients. Results: Congenital spinal malformations were more frequent among females 87 (60.4%) and between 0-20 years 135 (93.9%) of age. Tethered cord 97 (67.4%) was the most common congenital spinal abnormality followed by spina bifida, diastematomyelia, vertebral segmentation anomalies, myelomeningocele, menigocele. Lip-myelomeningocele, lipoma of filum terminale, and sacral agenesis. Frequently observed associated abnormalities included scoliosis 61 (42.4 %), syrinx 47 (32.6%) and dural ectasia 40 (27.8 %). Conclusion: Congenital spinal malformations are usually complex with variable radiological appearances. Modern high resolution MRI screening is the examination of choice for identification, preoperative evaluation, and long term follow up of such congenital anomalies. (author)

[en] Membrane-based natural gas separation has become one of the promising technologies due to its compactness, energy efficiency, environment friendliness and economic advantages. In this work, a three stage membrane process for the separation of CO/sub 2//CH/sub 4/ is proposed based on a novel fixed site carrier membrane which has the potential to meet the CO/sub 2//CH/sub 4/ separation and durability requirement. A simulation analysis, which utilizes the Aspen Hysys capabilities to calculate and couple energy balances in the process model, has been conducted to investigate the effect of process parameters on the gas processing cost. Two different natural gas mixtures containing 9.5% and 2.9% CO/sub 2/ have been simulated for various process conditions. This fixed site carrier membrane performs well when wetted with water. Therefore, natural gas feed streams are saturated with water. It is evident from the analysis that it is possible to maintain 2% CO/sub 2/ in retentate and methane loss in permeate below 2% by optimizing the process conditions. The analysis shows that fixed site carrier membrane offers a viable solution for natural gas sweetening. (author)

[en] In this review article global energy issue is discussed with specific reference to Pakistan. The energy consumption and supply from different sources like oil, gas, electricity, nuclear power, bio gas and especially from renewables is taken into account. Also discussed some suggestions for the energy requirements. Focus is given to the production of renewable energy sources like technology of photovoltaics in which solar power is converted into electricity. Solar cell is discussed including its two basic types inorganic solar cell and organic solar cell, its way of functioning, process of fabrication etc is also discussed. Organic or polymeric solar cell is discussed in detail. keeping in view the financial condition and requirement of energy for our country suggestions are given for low cost and simple processing of organic solar cells. It is also suggested that availability of all the materials required for the development of organic solar cells should be guaranteed. Interest should be developed at the university and other research organization level of Pakistan to do work on polymeric solar cells for increasing their efficiencies so that they can be practically utilized. (author)

[en] Objective: To evaluate human epidermal growth factor receptor 2 (HER2/neu) interobserver variability between specially trained and untrained general histopathologists. Methods: The retrospective study cases of invasive breast carcinoma received at Shifa International Hospital, Islamabad, from June 2010 to December 2011, for assessment of HER2/neu status by immunohistochemistry which were retrieved from the files and, 30 consecutive cases each of score 0, 1+, 2+ and 3+ were selected for a total of 120 cases. Two groups of two histopathologists each examined the cases blindly. One group had attended a short course in Germany, while the other group comprised two qualified histopathologists who had not had any special training. Each histopathologist reported the cases independently according to standard guidelines. Kappa statistics were applied. Results: The trained group of histopathologists showed agreement in 113 (94%) cases. Kappa value was calculated to be 0.96 which means perfect agreement. In contrast the untrained group showed agreement in 83 (69%) cases with a kappa value of 0.59 which means moderate agreement. Conclusion: Interobserver variability in immunohistochemical scoring of HER-2/neu in breast carcinoma is high among untrained general histopathologists. This may adversely affect the selection of patients with cancers who could benefit from Herceptin therapy. (author)