PURSE 2011

Permanent URI for this collectionhttps://ir.lib.pdn.ac.lk/handle/20.500.14444/58

Browse

Now showing 1 - 9 of 9

Chemically bound Silver nanoparticles on cotton textiles exhibiting efficient inhibition of escherichia coli and staphylococcus aureus
(University of Peradeniya, 2011-11-24) Bandara, I .M. C. C. D.; Rajapakse, R. M. G.; Rajapakse, S.
This study describes a convenient method for production of highly durable antimicrobial textile against laundering. The method involves layer-by-Iayer electrostatic self-assembly process. Here, natural cellulose substrate was modified with chloroacetic acid in the presence of sodium hydroxide, followed by drying and curing. Then it was immersed in silver nitrate solution for reducing the electrostatically attached silver ions into nanosized silver coatings on textile using sodium citrate as the reducing agent. Average particle size obtained was approximately 16.54 nm. The modified textile was tested for Gram positive Staphylococcus aureus and Gram negative Escherichia coli and showed antimicrobial activity even after 30 washing cycles. Antimicrobial activities were tested for the silver nanoparticles chemically bound on textile subjected to 5, 10, 15, 20, 30 washing cycles and found that a constant inhibition zone of 2 mm was obtained in each case. Control experiments done with silver nanoparticles physically entrapped in cotton showed progressive decrease in the inhibition zone due to excessive washing cycles.
Comparative pharmacognostic studies on Cyperus rotundus Linn. and Kyllinga monocephaia Rottb. (Cyperaceae)
(University of Peradeniya, 2011-11-24) Sudusinghe, S. P.; Marasinghe, P.; Damunupola, J. W.
Cyperusrotundus Linn., a perennial grass like herb of Cyperaceae family which is widely used in Ayurvedic medicine, cosmetics and new drug formulations in allopathic medicine, is officially known as "Mustha" in the Ayurvedic Pharmacopeia. Locally, the plant is known as "Kalanduru". Kyllingamonocephala Rottb of the same family has similar characteristics to C. rotundus Linn. and the latter is adulterated by K. monocephala Rottb. In addition, K. monocephala appears under the official Ayurvedic name of C. rotundus: in' many documents and web sites which triggered the question of its usage as a substitute since it might be affecting the quality of the final product. Rhizomes of both plants are the parts used as medicine, and have similar appearances when presented as a crude drug and are hard to differentiate. This research was designed to compare the two plants using pharmacognostic methods employed to analyse plants or plant related substances. The methods comprised macroscopic, microscopic and chemical analyses. Fresh plants of C. rotundus and K. monocephala were collected from Seeduwa, Anuradhapura, Nawinna and market samples of crude drug were collected from Seeduwa, Peradeniya, Nawinna and Anuradhapura. Identification of the two plants was performed at the National Herbarium, Royal Botanical Gardens, Peradeniya. Comparative studies of the two plants were perfomed macroscopically and microscopically, by comparison of plant morphological structures such as rhizomes, stems, leaves and inflorescences. For microscopic analyses, slides were prepared from fresh rhizomes of both plants and also from the market samples of the crude drug. The thickness of the exodermis, endoderm is and parenchyma were measured using Image J 1.43U software. Iodine, Safranin and Sudan III tests were carried out to identify ergastic cell contents in rhizomes of both plants. Ten replicates (each containing three measurements) from each location were used for all the measurements mentioned above. Upon completion of the comparative study and statistical analyses it was evident that these two plants could be easily distinguished mainly from their inflorescences and from the width of the leaves which is larger in C. rotundus. However; most of the other morphological structures were similar. From microscopical studies, it was apparent that rhizomes of the two plants and their contents were very similar except the thickness of exodermis, parenchyma and endoderm is, which were greater in C. rotundus. In conclusion, more advanced procedures such as chemical assay tests, ash value tests, quantification analysis of ergastic cell contents should be employed to compare the crude drug as well as the fresh rhizome of these two plants to evaluate the substitution of K. monocephala over C.rotundus in Ayurvedic medicine, cosmetics and drug formulations.
Comparison of antioxidant potential of Sri Lankan and Indian pomegranate (Punica granatum L.) Cultivars
(University of Peradeniya, 2011-11-24) Bopitiya, D,; Jayasooriya , J. A. P.L. P.; Madhujith, T.
Antioxidants, especially polyphenols, help to protect the body against oxidative stress by neutralising free radicals, reactive oxygen species (ROS) and reactive nitrogen species (RNS). The present study was carried out to determine the total phenolic content and antioxidant potential of extracts obtained from. the aril of Sri Lankan pomegranate (Punica granatum L) varieties (Nayana, Daya, Nimali) and an Indian variety. Well-ripened pomegranate fruits were obtained in August 2010 from the Regional Research Station, Department of Agriculture, Mankandura. Pomegranate juice was extracted by pressing the arils manually and filtering through Whatman No. 1 filter papers to remove particulate matter. The clear liquid devoid of particulate matter was used for analysis. Total Phenolic Content (TPC) was determined using Folin Ciocalteu colorimetric method and expressed as milligram of Gallic acid equivalents (GAE) per gram extract. Antioxidant potential of the fruit extracts was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Total Antioxidant Capacity (TAC) was determined using 2,2'-azinobis 3-ethylbenzothiazoline-6 sulphonic acid (ABTS) radical. DPPH radical scavenging capacity was expressed as IC value while TAC was expressed as percentage inhibition after lapse of 1 min. of the reaction. TPC of pomegranate varieties tested ranged from 0.015 to 0.164 mg GAE/g of extract. Daya variety possessed the highest TPC followed by Nayana, Nimali, and the Indian variety. The IC value of pomegranate extracts tested ranged from 0.182 mg/ml to 0.446 mg/ml with Nayana variety showing the highest antioxidant activity followed by the Indian variety, Nimali and Daya. Total Antioxidant Capacity (TAC) of pomegranate varieties tested varied from 72.73 - 93.1 % with the highest being observed in Nayana variety. The TAC of varieties Nayana, Nimali, Indian, Daya were 93.1%, 91.2%, 89.7% and 72.73%, respectively, at the 0.1g/ml concentration. Despite the moderate TPC, Nayana variety showed the highest antioxidant activity as measured by DPPH' scavenging activity (IC value 0.182 mg/ml) and the highest TAC (93.1% inhibition). On the other hand, Daya variety showed a relatively less antioxidant activity though it contained high level of TPC. The TPC and antioxidant activity as measured by TAC and IC value were not well correlated (R2 = 0.545 and 0.465, respectively). The poor correlation may be attributable to differential behaviour of phenolic constituents. Fruits with IC value of less than 1 mg/ ml are categorised as extremely high antioxidant potential fruits. Based on TAC and DPPH radical scavenging activity, pomegranate varieties tested can be categorised as fruits with high antioxidant potential.
Clinical and laboratory features of spotted fever rickettsioses in patients presented to teaching hospital, Peradeniya
(University of Peradeniya, 2011-11-24) Weerakoon, K. G. A. D.; Rajapakse, R. P. V. J.; Adikari, S. B.; Medagedara, S. C.; Nanayakkara, D. M.; Ranasingha, S.; Kularatne, S. A. M.
Spotted fever group rickettsioses (SFG) are predominantly seen in the central hills of Sri Lanka. Unfortunately, routine laboratory diagnostic facilities are not available in the hospitals. Therefore, logical use of the clinical features may help to arrive at a clinical diagnosis and to institute treatment, or otherwise delay in treatment could be detrimental. The aim of this study was to describe clinical and laboratory features of SFG from a prospective case series. Those patients who were presented to Medical Unit, General Hospital, Peradeniya from 2008-2010 with an IgG titer> 1/256 were included in the study. The confirmation of the diagnosis was made with Immunofluorescence antibody assays (IFA) which detected specific rickettsial IgM and IgG antibodies for Rickettsia conorii antigen. Ethical clearance for the study was obtained from ethical review committee, Faculty of medicine, Peradeniya. A total of 247 patients were confirmed to have either primary (19%) or secondary SFG (81%). Of them, 130 (53%) were males and 117 (47%) were females and the mean age of the group was 43 years (12 to 87 years). Patients were presented to the hospital after an average of six days (SO = 4) of fever. A maculopapular skin rash was observed in 78% and a rash with skin necrosis was seen in 6% of patients. Fever (98%), headache (95%), skin rash, arthralgia (70%), myalgia (84%), nausea (51%), vomiting (47%), cough (28%) and conjunctival injections (66%) were the predominant clinical findings. Leucopaenia, thrombocytopaenia and anaemia were seen in 17%, 74% and 19% of patients respectively. Both transaminases, (AST and ALT) were elevated in 66% of cases and ESR was elevatefd in 25 of 37 patients. Rapid response was noted with prompt administration of anti-rickettsial therapy including doxycycline or chloramphenicol. A wider clinical spectrum was noted among SFG patients. Cardinal clinical features such as skin rash, arthritis and response to anti-rickettsial antibiotics would help to arrive at a diagnosis. However, PCR and sero-diagnositic facilities must be available in the hospitals for confirmation of diagnosis.
Chirality dependence of elastic properties of supercarbon nanotubes
(University of Peradeniya, 2011-11-24) Gunatilake, P. A. G.; Herath, S. R.
Carbon nanomaterials are studied extensively among many nanoscale materials investigated during the last decade. Carbon nanotubes (CNT's) are linear fullerenes which can have aspect ratios as large as 103 to 105 . After the discovery of Y branching of CNT's, attention now is on the hierarchical structures (Supercarbon structures) which can be made of Single Walled Carbon Nanotubes (SWCNT's). When SWCNT's are arranged to form a higher order structure, it is called a supercarbon nanostructure. The present study focuses on the versatile elastic properties of Supercarbon nanotubes (SCNT's) which can be mastered by changing various parameters such as geometry and chirality of constituent SWCNT's and the chiral index of the SCNT. A simple mechanics model is used to estimate the stiffness of these supercarbon nanotubes and the results agree well with previous studies on these structures using molecular dynamics modelling. It was found that in super carbon nanotubes with Y junctions, the length of the constituent SWCNT and its chirality, influence the elastic modulus, stiffness and its ultimate tensile strength. Further the study shows that the higher the length of SWCNT the lesser the elastic modulus. It was also seen that for a given length, Lo ,and diameter, d, of SWCNT, the elastic modulus of the super nanotube turns out to be the same for both armchair and zigzag SWCNTs. By manipulating atoms to form different structures, it is possible to obtain different geometries of nano-structured materials. These new materials can be mastered to have desired material properties in any range. Therefore, these can be used to make bullet-proof clothes and vehicles, high-strength composite materials, nano electromechanical devices (NEMS) etc. At the same time, these low density, flexible materials can be used in light weight composite structures.
Chitosan based nano-carrier system for controlled release of Ascorbic Acid
(University of Peradeniya, 2011-11-24) Menikarachchi, M. A. S. K.; Karunaratne, N.; Karunaratne, V.
There is an increasing interest in the development of new delivery systems for the controlled release of drugs and bioactive agents. Among these delivery systems, encapsulation of the drugs using a biodegradable matrix shows a promising pathway for the enhancement of the bioavailability of the drugs. The aim of the present study was to produce a chitosan-based nano-carrier system and check the release properties of the entrapped drug comparatively to the release of the free drug, to ensure whether there is a controlled release property in the nano-carrier system. Chitosan is a non-toxic, biodegradable and bio compatible polymer with interesting biological and chemical properties. Ascorbic acid (Vitamin C) was used as a model drug for the process. Ascorbic acid trapped lysosomes were coated with chitosan, with the aid of Tween 80 and sodium sulphate. The chemical structure was analyzed by FTIR and controlled release of ascorbic acid from encapsulated particles over seven hours shows a distinguishable enhancement comparable to free ascorbic acid release.
Chronic prostatitis: symptomatology and the impact on the quality of life in a Sri Lankan population
(University of Peradeniya, 2011-11-24) Pethiyagoda, A. U. B.; Priyadarshanl, R. M. S.; Bandara, H. G. W. A. P. L.; Weragoda, W. A. R. V.
Chronic prostatitis (CP) or Chronic Pelvic Pain Syndrome (CPPS) affects men in all ethnic origins where they experience considerable morbidity and may remain symptomatic for years as there is limited understanding of the pathophysiology and the optimal treatment.The data regarding Sri Lankan patients remain sparse. The objective of this study was study the symptomatology associated with CP/CPPS in a Sri Lankan population and to evaluate its impact on their quality of life (QOL). A descriptive cross sectional study was conducted in the surgical unit and Genito-Urology clinic in Teaching Hospital Peradeniya from March 2010 to August 2011. The study group included all patients who were clinically diagnosed with CP/CPPS according to the National Institutes of Health (NIH) definition. Symptomatology and QOL were evaluated with NIH Chronic Prostatitis Symptom Index (NIH-CPSI), a nine-item tool with 4 subscores and a total score ranging from 0-43 points, and with higher scores indicating more severe symptoms. The study group included 43 subjects with a mean age of 36.3 (SD=12.21) years with an age range of 18-65 years. The duration of symptoms at presentation ranged from 3 months to 7 years. The commonest presentations were pelvic pain (n=43) involving suprapubic area, urethra or testicles and urinary symptoms (n=38) includ.ing dysuria, frequency and poor emptying. Of the total study group 44.18% (n=19) experienced post ejaculatory pain. NIH-CPSI indicated that except 4. others had experienced pelvic pain commonly in suprapubic area (n=34) during the week prior to assessment while n=35 had dysuria and n=15 had post ejaculatory pain. The average pain was 8.95 measured on visual analogues scale. Most had poor emptying (n=30) and frequency (n=33) as urinary symptoms. Symptoms of 88.37% of patients (n=38) had interfered their usual activities. QOL was affected in all except one. Among affected. most '(n=20) were unhappy to spend the rest of life with their symptoms and n=18 had mixed feeling about it. The Pain score ranged from 0-17 while the urinary symptom score, QOL Impact, Symptom Scale Score and Total score displayed a range of 0-10,0-12,0-27 and 0-37 respectively. Of the study population 55.81% (n=24) had symptoms of moderate severity while 27.9% (n= 12) had severe symptoms. Pelvic pain, urinary symptoms and post ejaculatory pain are the commonest symptoms among local patients with CP who show a broad age range. The symptoms display a wide range of degree of severity and it affects the QOL in 97.67%. Further extensive research are required regarding Sri Lankan patients.
Classical Athenian family in the limelight: was there affection between Athenian spouses?
(University of Peradeniya, 2011-11-24) Wickramasinghe, C. S. M.
The objective of the study is to re-examine the literary evidence in par with the vase paintings that show scenes from domestic settings in order to perceive whether any affection existed among Athenian spouses because the interpretations given with regard to some such domestic settings seem problematic. The generally accepted view based on the conceptions of the authors of normative texts is that the Athenians considered their wives only as a machine which produce legitimate children and they looked for courtesans, prostitutes and hetaerae (respectable courtesans) for entertainment and that they bore no sentiments of affection for their spouses. Many paintings on Attic red and black figure vases are interpreted and explained following such perceptions. Yet, information from literary sources, more precisely those from Athenian drama and law court speeches infer that the condition of Athenian families was flat as stern and cold as preached and promoted by normative writers such as Plato and Aristotle. This idea is further confirmed through many domestic scenes depicted in Athenian vases such as the domestic scene shown on the Harvard hydria. The scene on it can be interpreted as demonstrating a nucleus of an Athenian family comprising a mother, father and child (with a maid). Not everyone was ready to accept this point of view, probably, when looking at the youth with restrained thoughts of Plato, Aristotle and Xenophon, who describe the husband or the groom as twice as old as the bride which easily fits with the cold relationships they instilled into their relationships when they further asserted that the husbands spent more time outside their homes perhaps in the agora or gymnasium with their peers and not with the family at home. Yet, information from Athenian dramatists and orators pile up in favour of warm affection between spouses. The insight we are provided with through a meticulous study of our literary sources and vase paintings is that there were positive sentiments such as warm affection between Athenian spouses as in any other normal society in antiquity or in our era. This cold and negative picture on the relationship between Athenian spouses has resulted from taking the perceptions of authors of normative texts, whose intention was to present the ideal picture they expected of their society but not the real scenario, as the ultimate characteristic of the Athenian society.
Agricultural risk factors of chronic kidney disease of unknown aetiology in North Central region of Sri Lanka
(University of Peradeniya, 2011-11-24) Jayasekara, J. M. K. B; Dissanayake, D. M; Gunaratna, M. D. N; Thilakarathna, S; Sivakanesan, R
Health professionals inSri Lanka havenoticed ahigh incidence of anewformof chronic kid!leydisease of unknown aetiology (CKO-U) infarmers ofNorthCentral Region (NCR). neaimof thestudywas to identify the risk factors related to farming inorder to implement oreventive strategies. Potential agricultural risk factors and other information were collected through interviewer-administered questionnaires given to 315 CKO-U patients anI 321 healthy controls that were randomly selected. The relative risk of each factor was cornpared in terms ofOdds ratios (ORs) and95%confidence interval (CI) by applying th.. linear logisticmodel. In-olvernent In paddy farming activities (OR = 1.945. 95%CI: 1.256-3.010) usage of aqro-chemicals (OR=2.034, 95%CI: 1297-3.190), poor preventive measures when usin.. agro-chemicals (OR = 2845. 95% CI. 1788-4527), high operated paddy extent WithJutexchange of labour (OR= 4734, 95%CI: 2.586-8.665) were identified as significant ·;ontributory risk factors forCKO-U (p<0.005). Cultivating a large landextent without hiri 19 labour was asignificant risk factor for thedisease (p<005) Furthermore. cultivating ·.maller landextent without hired labour (OR= 1558,95% CI .047-1.56) had higher risk thancultivating larger landextent with hired labour (OR= 140. 95%CI: 042142j Inatdition to the agricultural activities. being amale. age> 60 years. smoking. alcoholism. family history of CKO-U. history ofmalaria and snake bites (p<0.05) were identified a;other contributory factors. It ere IS a strong occupational risk factor in the pathogenesis of the disease where the 11alefarmers of >60 of age were at a high risk probably due to long term exposure t,) the aetiotoqical agents (risk factors) Agricultural activities involvinq intense physical acivity were related toCKO-U Further studies are indicated to identify theeffect of dehydraion and physical exertion on the renal functions of these individuals. Poor preventive measures inagrochemical usage related to thedisease indicate the need to educate th{ farmers onsafeagrochemical usage.

Browse

Recent Submissions