University of Kelaniya
  • Kelaniya, Sri Lanka
Recent publications
Improvement in the efficiency of organic solar cell (OSC) is one of the hot topics of the modern-day research. Despite environment friendliness and several other practical advantages, the power conversion efficiency (PCE) of OSC has not yet achieved the levels of the commercial inorganic solar cells. In this context, molecular tailoring of the donor and acceptor materials can help in alignment of the energy levels in order to improve PCE. In this study, we demonstrate the introduction of different functional groups on the most widely used donor and acceptor materials namely poly(3-hexylthiophene) (P3HT) and fullerene, respectively. P3HT was successfully converted into poly(4-bromo-3-hexylthiophene), poly(4-chloro-3-hexylthiophene), and poly(3-hexyl-4-nitrothiophene) through bromination, chlorination, and nitration reactions, respectively. Similarly, fullerene was converted into phenyl-C61-pentanoic acid methyl ester, phenyl-C61-pentanoic acid, and methyl-2-C61 propionate. The success of different modifications on P3HT and fullerene was monitored by ¹H NMR spectroscopy. Finally, the optoelectronic properties after the above-mentioned modifications were evaluated by UV–Vis spectroscopy and cyclic voltammetry.
Non-alcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease. NAFLD is estimated to affect 25% of the global population. Therefore, it is widely encountered in primary care. A proportion of patients with NAFLD need a specialist referral, evaluation and follow-up. There have been many updated guidelines on the management of NAFLD in the past few years. Given the burden of NAFLD in the community and its cardiovascular and liver-related adverse outcomes, knowledge of evidence-based standards of care for these patients is essential for any practitioner managing patients with NAFLD. As an asymptomatic disease in the early stages, NAFLD can lead to many mistakes in its management. We aim to highlight some common mistakes in managing NAFLD and attempt to provide evidence-based recommendations.
Despite COVID-19 vaccination, immune escape of new SARS-CoV-2 variants has created an urgent priority to identify additional antiviral drugs. Targeting main protease (Mpro) expressed by SARS-CoV-2 is a therapeutic strategy for drug development due to its prominent role in viral replication cycle. Leaves of Murraya koenigii are used in various traditional medicinal applications and this plant is known as a rich source of carbazole alkaloids. Thus, this computational study was designed to investigate the inhibitory potential of carbazole alkaloids from Murraya koenigii against Mpro. Molecular docking was initially used to determine the binding affinity and molecular interactions of carbazole alkaloids and the reference inhibitor (3WL) in the active site of SARS-CoV-2 Mpro (PDB ID: 6M2N).The top scoring compounds were further assessed for protein structure flexibility, physicochemical properties and drug-likeness, pharmacokinetic and toxicity (ADME/T) properties, antiviral activity, and pharmacophore modeling. Five carbazole alkaloids (koenigicine, mukonicine, o-methylmurrayamine A, koenine, and girinimbine) displayed a unique binding mechanism that shielded the catalytic dyad of Mpro with stronger binding affinities and molecular interactions than 3WL. Furthermore, the compounds with high affinity displayed favorable physicochemical and ADME/T properties that satisfied the criteria for oral bioavailability and druggability. The pharmacophore modeling study shows shared pharmacophoric features of those compounds for their biological interaction with Mpro. During the molecular dynamics simulation, the top docking complexes demonstrated precise stability except koenigicine. Therefore, mukonicine, o-methylmurrayamine A, koenine, and girinimbine may have the potential to restrict SARS-CoV-2 replication by inactivating the Mpro catalytic activity.
Background Allergy to Apis dorsata (Giant Asian Honeybee) venom is the commonest insect allergy in Sri Lanka and South East Asia. However, laboratory diagnosis is difficult as the pure venom and diagnostic reagents are not commercially available. Objective This study assessed the use of four recombinant allergens of A. mellifera venom and the passive basophil activation test in the diagnosis of A. dorsata venom anaphylaxis. Methods Serum IgE levels to four recombinant allergens of A. mellifera , rApi m 1, 2, 5 and 10 were assessed and compared with serum IgE to the crude venom of A. mellifera or V. vulgaris by Phadia ImmunoCAP, in patients who developed anaphylaxis to A. dorsata stings. Basophil activation in response to venom of A. dorsata or V. affinis was assessed using a passive basophil activation test. Association of the severity of the reaction with basophil activation was compared. Results rApi m 1 and 10 combinedly had significant correlation (r = 0.722; p < 0.001) with the crude venom of A. mellifera (Western honeybee) and a higher positivity rate of 90% (27/30). Whereas, IgE reactivity to rApi m 2 or 5 had significant correlation (p = 0.02 and p = 0.005 respectively) with V. vulgaris crude venom. All 30 (100%) were positive to A. dorsata venom in passive BAT; 70% (21/30) had over 80% activation, 96.7% (29/30) had over 60% activation and 100% had over 50% activation. Percentage activation of basophils in patients who had mild or moderate reactions (n = 20) was significantly low (p = 0.02) from that of patients who had severe reactions (n = 10). Conclusions rApi m 1 and 10 when combined was sensitive for the diagnosis of A. dorsata allergy. This combination had the lowest cross-reactivity rate with Vespula vulgaris . The passive BAT is highly sensitive in A. dorsata allergy. The basophil reactivity was significantly higher in severe anaphylaxis compared to mild/moderate anaphylaxis. This finding should be further explored in further studies.
In this book we have seen a few powerful solutions for solving security issues in fog computing in a wide variety of architectures and applications. In examining the accomplishments of these solutions, we have also seen that many unanswered questions remain. We will summarize what has been achieved in the field of fog computing from 5G to 6G and what are the most interesting and important directions for future research.
Dengue is a fast-spreading mosquito-borne viral disease in the world. The primary vector of the disease is Aedes aegypti of the family Culicidae. It is a container breeder. Since a vaccine or a drug has not been developed against dengue, vector control appears to be the best method so far to control dengue. The current study was conducted to determine the effect of delayed mating on fecundity, fertility, life-history parameters, and longevity of Ae. aegypti , because such information can help formulate integrated vector control strategies involving the release of sub-fertile males into the environment. During this study, mating was delayed by 0, 2, 5, and 8 days after emergence. Males and females were separated by hand at the pupal stage using the apparent size difference of the sexes. The separated pupae were kept in separate cages until emergence. When mating was delayed for 8 days, the number of eggs laid by the female declined by 38%, and the percentage number of eggs that hatched reduced by 24%. However, the percentage of larval mortality, duration of the larval and pupal periods, and adult longevity were not significantly affected. The current results indicate that delayed mating has a negative effect on the reproductive performance of vector mosquitoes.
International travel, a major risk factor for imported malaria, has emerged as an important challenge in sustaining malaria elimination and prevention of its reestablishment. To make travel and trade safe, the WHO adopted the International Health Regulations (IHR) which provides a legal framework for the prevention, detection, and containment of public health risks at source. We conducted a systematic review to assess the relevance and the extent of implementation of IHR practices that can play a role in reducing malaria transmission. Selected studies addressed control, elimination, and prevention of reestablishment of malaria. Study themes focused on appraisal of surveillance and response, updating national policies to facilitate malaria control and elimination, travel as a risk factor for malaria and risk mitigation methods, vector control, transfusion malaria, competing interests, malaria in border areas, and other challenges posed by emerging communicable diseases on malaria control and elimination efforts. Review results indicate that malaria has not been prioritized as part of the IHR nor has the IHR focused on vector-borne diseases such as malaria. The IHR framework in its current format can be applied to malaria and other vector-borne diseases to strengthen surveillance and response, overcome challenges at borders, and improve data sharing—especially among countries moving toward elimination—but additional guidelines are required. Application of the IHR in countries in the malaria control phase may not be effective until the disease burden is brought down to elimination levels. Considering existing global elimination goals, the application of IHR for malaria should be urgently reviewed and included as part of the IHR.
Background: South Asians are at high risk of type 2 diabetes (T2D). Lifestyle modification is effective at preventing T2D amongst South Asians, but the approaches to screening and intervention are limited by high costs, poor scalability and thus low impact on T2D burden. An intensive family-based lifestyle modification programme for the prevention of T2D was developed. The aim of the iHealth-T2D trial is to compare the effectiveness of this programme with usual care. Methods: The iHealth-T2D trial is designed as a cluster randomised controlled trial (RCT) conducted at 120 sites across India, Pakistan, Sri Lanka and the UK. A total of 3682 South Asian men and women with age between 40 and 70 years without T2D but at elevated risk for T2D [defined by central obesity (waist circumference ≥ 95 cm in Sri Lanka or ≥ 100 cm in India, Pakistan and the UK) and/or prediabetes (HbA1c ≥ 6.0%)] were included in the trial. Here, we describe in detail the statistical analysis plan (SAP), which was finalised before outcomes were available to the investigators. The primary outcome will be evaluated after 3 years of follow-up after enrolment to the study and is defined as T2D incidence in the intervention arm compared to usual care. Secondary outcomes are evaluated both after 1 and 3 years of follow-up and include biochemical measurements, anthropometric measurements, behavioural components and treatment compliance. Discussion: The iHealth-T2D trial will provide evidence of whether an intensive family-based lifestyle modification programme for South Asians who are at high risk for T2D is effective in the prevention of T2D. The data from the trial will be analysed according to this pre-specified SAP. Ethics and dissemination: The trial was approved by the international review board of each participating study site. Study findings will be disseminated through peer-reviewed publications and in conference presentations. Trial registration: EudraCT 2016-001,350-18 . Registered on 14 April 2016. Clinicaltrials: gov NCT02949739 . Registered on 31 October 2016.
Intentionally added MPs in PCCPs have created concerning threats to the environment. Therefore, this study aimed to screen synthetic polymers having MPs favoring chemical properties in PCCPs while estimating the theoretical emission into the environment and the level of awareness on the availability of MPs in PCCPs. A questionnaire survey was conducted via Google form using a complete random sampling method (n = 312). Next, a market survey was conducted and theoretical estimations were calculated for the products that recorded the highest MPs favoring polymers. Toothpaste products were identified as mostly used (95.8 %) and face cleanser (20.8 %) as least used. Of those MP ingredients, many chemical ingredients (11) were acrylate copolymers, and dimethicone polymers (5). A total of 21.4 trillion MP particles are released to the environment annually from considered four PCCPs. This study evidenced the availability of MP favoring chemicals in PCCPs in the Sri Lankan market that need further assessments.
Studies addressing the macrobenthic diversity and their potential as bioindicators in water quality assessment programs are sparse for Sri Lanka. The present study investigated the macrobenthic diversity in relation to water quality parameters in some urban reservoirs in the Western Province of Sri Lanka, assessing their potential as bio‐indicators in water quality assessment programs. The six study reservoirs included the Ihalagama Tank, Peralanda Tank, Kesbewa Tank, Boralesgamuwa Tank, Bolgoda Lake and Beira Lake. The microbenthic fauna abundance at randomly selected locations (n = 9) in each reservoir and selected water quality parameters (temperature; pH; electrical conductivity; total dissolved solids; BOD5; dissolved nitrates; total dissolved phosphate and alkalinity of the overlying water at each location were measured between July 2020 and January 2021, using standard data collection methods). The species richness (SR), species heterogeneity (H′) and species evenness (J) of the macrobenthic fauna in each reservoir were calculated, and the abundance and water quality data analysed using ANOVA and PCA as appropriate. A total of 13 macrobenthic taxa (Glyphidrilus sp., Limnodrilus socialis, Dero sp., Stratiomyd larva, Chironomid larva, Bellamya sp., Melanoides tuberculata, Gyraulus sp., Lymnaea sp., Paludomus sp., Thiara sp., Ancylus sp. and Mesostoma sp.) were observed from the six study reservoirs. The oligochaete tubificid worm L. socialis dominated the sediment samples, accounting for more than 94.7% of the total macrobenthic abundance, with the highest relative abundance of this species observed in Beira Lake (99.3%). The species richness of the macrobenthic community was highest in the Ihalagama and Kesbewa tanks (SR = 5), while it was the lowest in the Peralanda Tank (SR = 2). Since the benthic community was mainly dominated by L. socialis, the lowest species heterogeneity and species evenness values were observed in Beira Lake (H′ = 0.05; J = 0.03). The values of the water quality parameters among the study reservoirs varied, with Beira Lake exhibiting significantly high BOD5, dissolved nitrate, and total dissolved phosphate values (p < .05) than the other reservoirs, indicating a higher degree of eutrophication. Furthermore, the SR, J and H′ values for the study reservoirs decreased with increasing BOD5, dissolved nitrate and total dissolved phosphate levels. Thus, it was concluded that the abundance and diversity of macrobenthic fauna are primarily governed by water quality parameters. Furthermore, L. socialis can be used as a potential bioindicator organism in water quality assessment programs in urban reservoirs.
There is an urgent need to focus on the mental well-being of Syrians living in their motherland and displaced as refugees. There should be a scientific methodology for uplifting services, and discussions between mental health experts from neighbouring nations could initiate such a process.
Most of the injuries and deaths from ricocheting bullets in shooting incidents are usually reported due to misaimed shots that had ricocheted close to the victims. Although the destabilisation of ricocheted bullets during their ricochet flights is a generally known phenomenon, no significant quantitative-based scientific studies have attempted to understand bullets’ post-ricochet orientations at close distances. This empirical study explores close-range post-ricochet orientations of AK bullets (7.62 mm × 39 mm) on a range of domestic surface types typically encountered during bullet ricochet incidents. This study has revealed that ricocheting AK bullets off of various wood types and tile samples produce side-on impacts into closely located targets following a rightwards yaw action. It has also been shown that AK bullets ricocheting off concrete and cement samples at 5-degree incident angles produced nose-forward impacts on paper witness screens, similar to an orthogonal impact of a direct-fired shot. The findings present important new information on the post-ricochet yawing behaviour of AK bullets, which has the potential to aid future shooting reconstructions in which victims are hit by closely ricocheted bullets.
Prosopis juliflora is an invasive plant species rapidly expanding in the Asian and African continents. The invasion of P. juliflora in Bundala Ramsar Wetland (BRW) in Sri Lanka has created several biodiversity conservation issues. This study was conducted to assess the possibility of utilizing invasive P. juliflora as an alternative energy source. P. juliflora performed better than L. leucocephala for most evaluated fuelwood properties. Ash content was comparatively higher in P. juliflora than L. leucocephala. However, biomass to ash ratio of P. juliflora was significantly lower (<0.05) and the Fuel Value Index (FVI) of P. juliflora (3,276) was slightly lower than that of L. leucocephala (3,336), a non-significant difference. P. juliflora and L. leucocephala reached Fiber Saturation Point within 24 and 27 days of drying, respectively. Results show that 1 kg of P. juliflora would produce an estimated energy equivalent to 0.5 L of diesel and furnace oil and 5 kWh of electricity. As such, we recommend further study on harvesting and commercialization of P. juliflora as a potential wood energy source.
Remediation of hexavalent chromium with conventional chemical and physical methods is a costly process, while replacing some critical steps in physiochemical remediation with self-sustaining bioremediation agents are expected to be cost-effective and environmentally friendly implementation. In this study, a microalga isolated from a freshwater stream receiving treated textile wastewater was identified up to its molecular level and investigated its ability to tolerate and remove hexavalent chromium from extremely acidic conditions under different temperatures. The ability of microalgae to tolerate and remove Cr(VI) was investigated by growing it in BG11 media with different pH (1, 2, 3 & 7), amended with several concentrations of Cr(VI) and incubated under different temperatures for 96 hrs. Microalga was identified as Chlorella vulgaris and found that the isolated strain has a higher hexavalent chromium removal potential in extremely acidic conditions than in neutral pH conditions at 25 °C. In contrast, its Cr(VI) removal potential is significantly influenced by the pH and temperature of the growth medium. Furthermore, it exhibited a permanent viability loss at extreme acidic conditions (pH 1 − 3) and prolonged exposure to the higher chromium content. The microalga investigated will be a highly useful bioagent in hexavalent chromium remediation in high acidic conditions.
Background Well-being is an important aspect of people’s lives and can be considered as an index of social progress. The Warwick Edinburgh Mental Well-being scale (WEMWBS) was developed to capture subjective mental well-being. It is a widely tested measure of mental well-being at the population level and has 14 items and a short-form with 7 items. This study was carried out to culturally validate and adapt the WEMWBS among a Sinhala speaking population in Sri Lanka. Methods A forward and backward translation of the scale into Sinhala was done followed by a cognitive interview. The translated and culturally adapted scale and other mental health scales were administered to a sample of 294 persons between the ages of 17–73 using a paper-based version ( n = 210) and an online survey ( n = 84). Internal consistency reliability and test–retest reliability were tested. Construct validity, and convergent and discriminant validity were assessed using the total sample. Results The translated questionnaire had good face and content validity. Internal consistency reliability was 0.91 and 0.84 for the 14-item and 7-item scales, respectively. Test–retest reliability over two weeks was satisfactory (Spearman r = 0.72 p < 0.001). Confirmatory factor analysis supported a one factor model. Convergent validity was assessed using WHO-5 well-being index (Spearman r = 0.67, p < 0.001), Patient Health Questionnaire (PHQ-9) (Spearman r = (-0.45), p < 0.001) and Kessler psychological distress scale (K10) (Spearman r = (-0.55), p < 0.001). Conclusions The translated and culturally adapted Sinhala version of the WEMWBS has acceptable psychometric properties to assess mental well-being at the population level among the Sinhala speaking population in Sri Lanka.
Anemia is a global health problem. This paper reviews literature on the prevalence of anemia in Sri Lanka. We searched EBSCO (Elton Bryson Stephens Company), Cochrane Library, and Medline for articles on prevalence and molecular basis of anemia in Sri Lanka from January 2000 to May 2021. Forty articles were selected. Most of the studies were on prevalence of anemia among children and pregnant women. All the studies had restricted themselves to assess the contributing factors for anemia in limited age categories. Most articles had attempted to determine the overall prevalence of anemia and the contribution of iron deficiency to it. There were only a few studies on prevalence and molecular basis of hemoglobinopathies and even fewer on the prevalence of anemia of chronic disease. None of the studies had attempted to assess the national prevalence of red cell membranopathies and enzymopathies. The published data on prevalence of anemia in Sri Lanka are incomplete. This review emphasizes the value of a much broader survey on anemia covering all age categories including the elderly and conducting a national survey including anemia of chronic disease and on red cell membranopathies and enzymopathies in Sri Lanka.
Fungal involvement in biodeterioration of Low Density Polyethylene (LDPE) has received a great attention in recent years. Among diverse groups of fungi, Endolichenic Fungi (ELF) are adapted to thrive in resource limited conditions. Present study was designed to investigate the potential of mangrove associated ELF, in biodeterioration of LDPE and to quantify key‐depolymerizing enzymes. A total of 31 ELF species, isolated from 22 lichens of mangrove ecosystems in Negombo lagoon, Sri Lanka were identified using DNA barcoding techniques. ELF were inoculated into mineral salt medium, containing LDPE strips and incubated at 28±2°C, for 21 days, under laboratory conditions. After incubation, biodeterioration was monitored based on percent reductions in weights and tensile properties, increments in degree of water absorption, changes in peaks of Infrared spectra and surface erosions using Scanning Electron Microscopy. Out of 31 species, Chaetomium globosum, Daldinia eschscholtzii, Neofusicoccum occulatum, Phanerochaete chrysosporium, Schizophyllum commune and Xylaria feejeensis showed significant changes. Production of depolymerizing enzymes by these species, were assayed qualitatively using plate‐based methods and quantitatively by mass level enzyme production. Among them Phanerochaete chrysosporium showed the highest enzyme activities as (9.69±0.04)x10‐3, (1.96±0.01)x10‐3, (5.73±0.03)x10‐3, (0.88±0.01), (0.64±0.06), (1.43±0.01) U ml‐1 for laccase, lignin peroxidase, manganese peroxidase, amylase, lipase and esterase, respectively.
Background Segment-specific variations of carotid intima-media thickness (CIMT) have not been assessed in South Asian populations. The purpose of this study was to determine if segment-specific CIMTs or a composite-CIMT score is a better risk predictor of coronary heart disease in South Asian populations. Methods A comparative prospective study was conducted from November 2019 to October 2020 in a hospital in Colombo, Sri Lanka. Based on pre-defined inclusion and exclusion criteria, cases (having a diagnosis of Coronary Heart Disease (CHD), n = 338) and controls (non-CHD group, n = 356) were recruited. Ultrasound examination of the common carotid (CCA), the carotid bulb (CB) and the internal carotid segments (ICA) of the carotid vessels was conducted by a radiologist, and CIMTs were measured. A composite-CIMT score defined as the average value of all six segments of the left and right sides was derived. Results 694 participants were enrolled (male n = 399, 57.5%). The mean (±SD) age of the study sample was 60.2 (±9.86) years. There were variations in segment-specific values between the left and right vessels. The mean composite-CIMT value of the CHD group was significantly higher than that of the non-CHD group. A composite-CIMT score of 0.758 had a sensitivity of 98.4% and a specificity of 64.6% in distinguishing CHD from non-CHD groups (Area under the curve (AUC): 0.926). Conclusions Carotid artery segment-specific CIMT variations were present in this population. The composite CIMT score is better than segment-specific CIMTs in predicting CHD and may be used to predict CHD in this population.
Background Exposure to violence is associated with psychological distress, mental disorders such as depression, and suicidal behaviour. Most of the studies are conducted in the West, with limited publications from Asia. Thus, we conducted a scoping review of studies investigating the association between experiences of violence and later suicidal ideation/attempts from Asia in the twenty-first century. Results Many studies focused on domestic violence toward women in the Southeast Asian region. Sociocultural factors such as family disputes, public shaming, dowry, lack of education opportunities, and marriage life perceptions mediated the association. Many women exposed to violence and attempted suicide suffered from mental disorders such as depression, anxiety, and post-traumatic stress. The small number of suitable studies and the possible effect of confounders on participants were limitations in the review. Future studies would have to focus on specific types of violence and ethnoreligious beliefs. Conclusion Women in Asia exposed to violence appear to have an increased risk of suicidal behaviour and mental disorders. The early screening of psychological distress with culturally validated tools is essential for preventing suicides in Asian victims of violence.
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3,172 members
Aruna Kumara Ranaweera
  • Department of Physics and Electronics
Aruni Hapangama
  • Department of Psychiatry
Madawa Chandratilake
  • Faculty of Medicine
Sachith Mettananda
  • Department of Paediatrics
W. Nirmala Sriyani Perera
  • Dept.of Forensic Medicine
Kelaniya, Sri Lanka
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