Some indications from instability results about the effectiveness of wall heating as a control option for channel flow

This paper is a review of some of our recent work on the effect of wall heating on the stability of laminar flow in a channel. The summary of our results, some of them unexpected, is as follows. Viscosity stratification has very little effect on transient growth, whereas it results in linear mode stabilising or destabilising by an order of magnitude. It has hitherto been accepted that heat diffusivity does not affect stability. This is however true only for linear instability, transient growth is affected by an order of magnitude. Unusually, the growth is spanwise-independent and not in the form of streamwise vortices. It is also shown that flow is destabilised by secondary modes as the viscosity ratio increases. However, the viscosity ratio has no role in the selection of the pattern of ∧ vortices

Outcome of monocular surgery for horizontal strabismus in Hyderabad

Sameen A Junejo, Munawar A AnsariLiaquat University of Medical and Health Sciences/Jamshoro, Hyderabad-Sindh, PakistanBackground and objective: Squint surgery is frequently performed successfully in Hyderabad. However, no study in any detail has been performed on the outcome of monocular surgery for horizontal squint in the region. This study aims to determine the results of monocular surgery for horizontal trabismus.Design: Retrospective/observational study.Subjects and methods: The study was conducted on patients aged under 45 years, presenting with horizontal strabismus and undergoing monocular squint surgery. Anterior segment slit lamp examination, and if possible, posterior segment examination with 90 diopter (D) and 78 D fundoscopes was performed. Angle of deviation was measured. Patients were divided into two groups (esotropia and exotropia). Investigations were performed. Surgery was done under general anesthesia. A second surgical procedure was performed after six months for any residual deviations.Results: After squint surgery, patients in group 1 (79%) and in group 2 (73.3%) had residual deviation of less than 15 prism diopters (PD). The preoperative deviations of 60 PD or less illustrated excellent domino effects with residual deviation of fewer than 15 PD. Three patients with successive deviation underwent a second surgery with excellent outcomes.Conclusion: Few extraocular muscles can be prevented due to monocular squint surgery when multiple surgeries are needed.Keywords: horizontal strabismus, monocular surgery, Hyderaba

Analytic study of clinical presentation of intracranial space-occupying lesions in adult patients

Intracranial space-occupying lesions can be caused by a variety of disease processes, ranging from neoplasms to non-neoplastic lesions including hematomas, abscesses and vascular malformations. This article provides an overview of varied clinical presentations of patients with intracranial space-occupying lesions.Methods:A total of 200 cases of intracranial space-occupying lesions presenting at Neuro Clinic and Care were retrospectively analyzed. Adult patients from all age groups and both genders were included in this study. Results: 165 patients (82.5%) had neoplastic lesions while 35 (17.5%) had non-neoplastic lesions. Metastatic lesions from primary tumor elsewhere in the body comprised the most common group with81 cases (40.5%), followed by meningiomas with 27 cases (13.5%). Males were affected slightly more than females (1:0.8). The most common presenting symptom was headache 87 patients (43.5%,) followed by focal symptoms such as numbness, tingling or weakness being present in 80 (40%)and seizures observed in 65 (32.5%).Conclusion: The study reviews the wide range of symptoms the patients with intracranial space-occupying lesions present with, the most common being headache, followed by focal symptoms such as numbness, tingling or weakness, seizures and vomiting. Knowledge of these typical as well as atypical patterns of clinical presentation can aid physicians in timely detection and prompt application of diagnostic and therapeutic modalities

Efficacy of memantine in treating patients with fibromyalgia

To evaluate the efficacy of Memantine as a therapeutic intervention for fibromyalgia. Methods: This clinical trial was conducted between October 2014 and December 2014. A total of 30 subjects with diagnosed fibromyalgia presenting to a private neurology clinic in Karachi, Pakistan were selected through purposive sampling technique. Adult patients belonging to both genders were included in the study. Patients were treated with incremental doses of Memantine. Data was analyzed using SPSS version 20 and associations were made using Chi square test with p-value of less than 0.05 taken as significant. Results: Out of 30 patients, 2 (6.7%) were males and 28 (93.3%) were females which shows a very high occurrence of fibromyalgia in females. The mean age of the subjects was found to be 38 years. Efficacy of the drug in patients with fibromyalgia was observed to be 93.3% which is significantly high. The baseline FIQ score when compared with the score at 3-month follow-up by applying Wilcoxon signed rank test showed mean ± S.D (67.18±13.23 vs. 34.17±15.18) where p=0.000. This shows a highly significant result (≤0.05). All of the patients with fibromyalgia reported improvement in their physical functioning and majority of the patients felt less anxious and less depressed on their final follow-up visit. By the end of the 3rd month, the level of stiffness and intensity of pain decreased significantly and patients reported less difficulty in performing work. Conclusion: Memantine has shown significant beneficial effects in reducing the intensity of pain and disability in patients with fibromyalgia

Efficacy of memantine in treating patients with migraine and tension-type headache

Objective: To assess the efficacy of Memantine as a preventive and therapeutic intervention for migraine and tension-type headache. Methods: This clinical trial was conducted over a period of 3 months. A total of 44 subjects, with diagnosed migraine and/or tension-type headache, presenting to a private neurology clinic in Karachi, Pakistan were selected through purposive sampling technique. Patients were treated with incremental doses of Memantine. Adult patients belonging to both genders were included in the study. Data was analyzed using SPSS version 16.0 and associations were made using Chi square test with p-value of less than 0.05 taken as significant. Results: Out of 44 patients, 35 (79.5%) were females and 9 (20.5%) were males which shows a very high occurrence of migraine and tension-type headache in females. Average age was found to be 32.6 ≈ 33 years. Efficacy of the drug was observed to be 81.8% which is significantly high. The baseline MIDAS score when compared with the score at 3-month follow-up by applying Wilcoxon signed rank test showed mean ± S.D (39.52±21.27 vs. 6.72±6.41) where p=0.000 (\u3c0.05) which shows a highly significant result. All 44 patients were known cases of migraine while 25% (11) of them also suffered from tension-type headache. Patients were treated with incremental doses of Memantine and were observed for the efficacy of the drug. Patients maintained their diaries of intensity of pain, distressing influence of the pain and how it hindered their daily routine. Results showed that intensity of pain decreased significantly by the end of the 3rd month of treatment and majority of the patients felt less distressed on their final follow-up visit. By the end of the 3rd month, the level of hindrance in the daily routines of the patients caused by the headache also fell significantly. Conclusion: Memantine has significant beneficial effects in reducing intensity of pain and disability in patients with migraine and tension type headache

Nanopackaging of Silver using Spice Extract and their Characterization

The aim of the present study was to synthesize silver nanoparticles using spice extracts as reducing agents and further evaluate their anti-microbial activities. Silver has been shown to possess antimicrobial activity. The silver nanoparticles were prepared by solvent evaporation method. The silver nanoparticles were characterized by UV-Vis spectroscopy. The functional groups present in the phyto-constituents on the plant extract were determined by FT-IR studies. The particle size of the silver nanoparticles was determined by Dynamic Light Scattering and was found to be 143, 50 and 56 nm for cloves, cinnamon and neem silver nanoparticles respectively. They exhibited antibacterial property against Escherichia coli, Staphylococcus aureus and Salmonella typhi strains, tested using Well Diffusion method. Plant extracts however reduce the antimicrobial activity of the nanoparticles. In conclusion, antimicrobial activities of silver nanoparticles were reduced by plant extracts certifies vital potential in biomedical application.Keywords: Silver nanoparticles Neem Cinnamon Clove

Preventing transition to turbulence: a viscosity stratification does not always help

In channel flows a step on the route to turbulence is the formation of streaks, often due to algebraic growth of disturbances. While a variation of viscosity in the gradient direction often plays a large role in laminar-turbulent transition in shear flows, we show that it has, surprisingly, little effect on the algebraic growth. Non-uniform viscosity therefore may not always work as a flow-control strategy for maintaining the flow as laminar.Comment: 9 pages, 8 figure