Analysis of factors affecting for adoption of good agricultural practices in potato cultivation in Badulla district, Sri Lanka

Peer reviewedPublisher PD

Estimation of body weight using anthropometric parameters in Sri Lankan hospitalized adult patients

Body weight is an important clinical parameter for accurate dosing of drugs with a narrow therapeutic window, However, it is difficult to measure the body weight of a patient if they cannot stand on a scale. There are several anthropometrics-based equations to estimate the body weight, but most of these are derived from white Caucasian populations and are not validated for South Asians. This study aimed to validate existing anthropometrics-based weight estimation equations and develop a new equation for the same purpose for Sri Lankan adults. This prospective study was conducted at the National Hospital of Sri Lanka over a 6-month period, split into a development and a validation phase. During the development phase, estimated body weight of patients by doctors and nurses and patients themselves were noted and compared against their actual body weight. In addition, 13 anthropometric measurements were taken, which were used to validate 12 anthropometrics-based equations to estimate body weight described in literature previously. Two new gender specific regression models to estimate the body weight in the local population was also derived and validated. A total of 502 (males = 249) and 217 (males = 108) patients were recruited for the development and validation phases respectively. Both doctors and patients had comparable accuracy in predicting body weight (p>0.05). All anthropometric based equations were significantly correlated with actual body weight (correlation coefficients: 0.741–0.869), and the new equations derived from the local data performed similarly to the best performing equation identified from the literature during validation phase. However, even the best of these equations could not outperform patient/physician estimates. When the patient weight cannot be measured, an estimate by the patient or the doctor may be the best substitute

Outcomes of stroke patients undergoing thrombolysis in Sri Lanka; an observational prospective study from a low-middle income country

Background: Stroke related deaths are relatively higher in low- and middle-income countries where only a fraction of eligible patients undergo thrombolysis. There is also limited evidence on post-thrombolysis outcomes of patients from Asian countries in these income bands. Methods: This is a single center prospective observational study of a patient cohort with acute ischaemic stroke, undergoing thrombolysis with alteplase (low and standard dose), over a 24-month period in 2019/2020. Modified Rankin scale (mRS) for dependency at 3 months (primary outcome), duration of hospital stay, incidence of symptomatic intracranial haemorrhages and all-cause mortality at 3 months (secondary outcomes) were recorded. Demographic, clinical and treatment related factors associated with these outcomes were explored. Results: Eighty-nine patients (males – 61, 69%, mean age: 60 years ±12.18) were recruited. Time from symptom onset to reperfusion was 174 min ± 56.50. Fifty-one patients were independent according to mRS, 11 (12.4%) patients died, and 11 (12.5%) developed symptomatic intracranial haemorrhages by 3 months. Functional independence at 3 months was independently associated with National Institutes of Health Stroke Scale (NIHSS) on admission (p < 0.05). Thrombolysis with low dose alteplase did not lead to better or worse outcomes compared to standard dose. Conclusions: On admission NIHSS is predictive of functional independence at 3 months post-thrombolysis. Low dose alteplase may be as efficacious as standard dose alteplase with associated cost savings, but this needs to be confirmed by a prospective clinical trial for the Sri Lankan population

Composition and physicochemical properties of oat starches

Starches from two new oat varieties namely AC Stewart (Avena sativa L.) and NO 753-2 (Avena nuda L.) were isolated and some of their characteristics determined. The total amount of starch lipids (TSL) extracted by acid hydrolysis was 1.60% (w/w) in both starches. The free lipid content (extracted by chloroform-methanol (CM) 2:1 v/v at 25°C) was 0.36 and 0.30% (w/w) in NO 753-2 and AC Stewart starches, respectively. The bound lipid content (extracted by hot n-propanol-water 3:1 v/v from the residue left after CM extraction) was 1.27 and 1.37% (w/w) in NO 753-2 and AC Stewart starches, respectively. The total amylose contents were nearly the same (~23%, w/w) in both starches, of which 14.1 (NO 753-2) and 15.3% (AC Stewart) were complexed by native lipids. The starches differed widely in their degree of swelling, gelatinization transition temperatures and enthalpy, susceptibility towards acid and enzyme hydrolysis, gel strength, paste viscosity, thermal stability and retrogradation characteristics. The results suggest that the extent of interaction of starch chains within the amorphous and crystalline regions of the granule was stronger in NO 753-2 than in AC Stewart

Enzyme-assisted synthesis of structured lipids containing long-chain omega-3 and omega-6 polyunsaturated fatty acids

Lipase-catalyzed acidolysis of borage (Borago officinalis L.) and evening primrose (Oenothera biennis L.) oils with long-chain ω3-polyunsaturated fatty acids (LCω3-PUFA), namely docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA), in organic solvents was studied. Six microbial lipases from Candida antarctica, Mucor miehei, Pseudomonas sp., Aspergillus niger, Candida rugosa and Thermomyces lanuginosus were initially used as biocatalysts for the acidolysis reaction. Among the enzymes tested, an immobilized lipase, Novozym-435 from Candida antarctica showed the highest degree of DHA incorporation (25.8-28.7%, after 24 h) in borage oil (BO) and evening primrose oil (EPO). However, the maximum incorporation of EPA (28.7-30.7%, after 24 h) in both oils was achieved with lipase PS-30 from Pseudomonas sp. In another study, incorporation of EPA+DHA into BO and EPO was carried out by first screening of lipases listed above; lipase PS-30 from Pseudomonas sp. was the most efficient enzyme examined (31.7-32.7% EPA+DHA incorporation, after 24 h). -- Effects of variation of reaction parameters, namely enzyme load, temperature, time course, mole ratio of substrates and type of organic solvents were monitored for the most effective enzymes, those from Candida antarctica and Pseudomonas sp., as the biocatalysts of choice. Incorporation of DHA and/or EPA increased significantly (p ≤ 0.05) with increasing the amount of enzyme. As the incubation time progressed, incorporation of these fatty acids was also increased, similar to that observed when the temperature and mole ratio of substrates increased. The highest DHA (37.4-39.7%) or EPA (37.4-39.9%) incorporation occurred at a mole ratio of 1:3 (oil/ DHA or EPA). However, maximum incorporation of EPA+DHA (54-57.5%) occurred at a mole ratio of 1:2:2 (oil/EPA/DHA) and then remained constant between mole ratios of 1:2:2 and 1:3:3. Among solvents examined, n-hexane served best in giving rise to 25.5-27.4% DHA, 25.2-26.8% EPA and 27.8-33.3% EPA+DHA incorporation in the oils. However, solvent-free reactions also gave satisfactory incorporation of 18.1-20.5% DHA, 18.6-20.4% EPA and 23.4-28.8% EPA+DHA in the oils tested. -- Response surface methodology (RSM) was used to obtain a maximum yield of DHA, EPA and EPA+DHA incorporation while using the minimum amount of enzyme possible. Process parameters studied were the amount of enzyme (100-350 units), reaction temperature (20-60°C) and reaction time (6-30 h). All experiments were carried out according to a face-centred cube design. Under optimum conditions (162-165 units of Candida antarctica enzyme: 43-50°C; 25-27 h), incorporation of DHA was 35.6% in BO and 33.5% in EPO. Optimization of acidolysis of oils with EPA, gave rise to a maximum of 35.4 and 33.9% EPA incorporation in BO and EPO, respectively, at 299-309 units of Pseudomonas sp. enzyme, reaction temperature of 40-44°C and reaction time of 25-27 h. Similarly, maximum incorporation of EPA+DHA in BO (35.5%) and EPO (33.6%) was attained at 278-299 units of Pseudomonas sp enzyme, at 42-43°C after 24-26 h. -- In another study, enzymatically modified oils, produced under optimum reaction conditions, were classified using thin-layer chromatography-flame ionization detection (TLC-FID). The results showed that the content of TAG (85.1-95.1%) was much higher than that of the DAG (2.4-11.2%) and MAG (0.3-9.7%) in the structured lipids so produced. Because free fatty acids were removed by NaOH after the acidolysis reaction, they were not detected by TLC-FID. The products were also separated by TLC and the fatty acid compositions of their corresponding isolated bands analyzed by gas chromatography. Results showed that DHA and/or EPA were mainly located in TAG fractions of enzymatically modified oils (33.2-35.4% DHA; 32.5-33.2% EPA and 33.6-35.5% EPA+DHA in DHA, EPA and EPA+DHA-enriched oils, respectively). The TAG fractions also contained appreciable proportions of γ-linolenic acid (GLA) (11.0-17.1 and 7.5-7.6% in DHA, EPA and EPA+DHA-enriched BO and EPO, respectively). -- Stereospecific analysis was carried out to establish positional distribution of fatty acids in the TAG of DHA, EPA and EPA+DHA-enriched oils. In DHA-enriched BO, DHA was randomly distributed over the three positions of TAG while GLA was mainly esterified at the sn-2 and sn-3 positions. In DHA-enriched EPO, however, DHA and GLA were concentrated in the sn-2 position. In EPA-enriched BO, EPA was randomly distributed over the three positions of TAG, similar to that observed for DHA. In EPA-enriched EPO, however, this fatty acid was mainly located at the primary positions (sn-1 and sn-3) of TAG. In both oils, GLA was preferentially esterified at the sn-2 position. In EPA+DHA-enriched BO, EPA and DHA were mainly esterified at the sn-1 and sn-3 positions of TAG while GLA was mainly located at the sn-2 position. In EPA+DHA-enriched EPO, GLA was mainly located at the sn-2 and sn-3 positions; EPA was preferentially esterified at the sn-1 and sn-3 positions, while DHA was found mainly at the sn-3 position. -- The oxidative stability of enzymatically modified oils as well as their unmodified counterparts was evaluated under Schaal oven conditions at 60°C over a 96 h storage period. Conjugated dienes (CD), 2-thiobarbituric acid reactive substances (TBARS) and headspace volatiles were determined. In addition, proton nuclear magnetic resonance (¹H NMR) spectroscopy was used to monitor relative changes in the proton absorption pattern of the fatty acids of oils during storage. Among the oils examined, enzymatically modified products gave rise to higher CD and TBARS as compared to those of their unmodified counterparts. The main volatile compounds identified in enzymatically modified oils were acetaldehyde, propanal, butanal, pentanal, hexanal, heptanal, octanal and nonanal. However, the main volatile compound found in unmodified oils was hexanal. The contents of propanal and hexanal produced by enzymatically modified oils were significantly higher (p ≤ 0.05) than those produced by their unmodified counterparts. These results suggested that the modified oils were more prone to oxidation than their unmodified counterparts. -- The double bond index (DBI) and methylene bridge index (MBI), represent the number of double bonds and bis allylic methylene bridge positions in PUFA, respectively, were calculated. DBI and MBI of enzymatically modified oils were significantly (p ≤ 0.05) higher than those of their unmodified counterparts. During oxidation of oils, DBI and MBI were decreased. Regression analysis was carried out to correlate various parameters of oxidation (CD, TBARS, hexanal and propanal contents) with DBI and MBI of oils; a negative correlation (r = 0.574-0.975; p ≤ 0.1-0.05) existed between these variables. -- Relative changes of aliphatic to olefinic (Rao) and aliphatic to diallylmethylene (Rad) protons ratios, during oil oxidation, were determined by ¹H NMR spectroscopy. An increase in Rao and Rad values was obtained over the entire storage period. A highly significant correlation (r = 0.930-0.992; p ≤ 0.005) existed between the CD values and changes in Rao and Rad during oxidation of all oils. The correlation coefficient between TBARS and changes in Rao and Rad values was in the range of 0.779 -0.983 (p ≤ 0.05). A high correlation (r = 0.948-0.996; p ≤ 0.005) was found between hexanal content and Rao and Rad of oils. Propanal content was also highly correlated (r = 0.950-0.990; p ≤ 0.005) with Rao and Rad. This suggests that ¹H NMR could be used to simultaneously estimate both primary and secondary oxidation changes in native and enzymatically modified oils

The influence of nano-architectured CeOx supports in RhPd/CeO2 for the catalytic ethanol steam reforming reaction

The ethanol steam reforming (ESR) reaction has been tested over RhPd supported on polycrystalline ceria in comparison to structured supports composed of nanoshaped CeO2 cubes and CeO2 rods tailored toward the production of hydrogen. At 650-700 K the hydrogen yield follows the trend RhPd/CeO(2)cubes >RhPd/CeO2-rods >RhPd/CeO2-polycrystalline, whereas at temperatures higher than 800K the catalytic performance of all samples is similar and close to the thermodynamic equilibrium. The improved performance of RhPd/CeO2-cubes and RhPd/CeO2-rods for ESR at low temperature is mainly ascribed to higher water-gas shift activity and a strong interaction between the bimetallic-oxide support interaction. STEM analysis shows the existence of RhPd alloyed nanoparticles in all samples, with no apparent relationship between ESR performance and RhPd particle size. X-ray diffraction under operating conditions shows metal reorganization on {1 0 0} and {1 1 0} ceria crystallographic planes during catalyst activation and ESR, but not on {1 1 1} ceria crystallographic planes. The RhPd reconstructing and tuned activation over ceria nanocubes and nanorods is considered the main reason for better catalytic activity with respect to conventional catalysts based on polycrystalline ceria. (C) 2015 Elsevier B.V. All rights reserved.Postprint (author's final draft

Extraction of Scandium (III) from acidic solutions using organo-phosphoric acid reagents: A comparative study

Comparative and synergistic solvent extraction of Sc(III) using two phosphoric acidic reagents such as di-(2-ethyhexyl) phosphoric acid and 2,4,4,tri-methyl,pentyl-phosphinic acid was investigated. Slope analysis method suggests a cation exchange reaction of Sc(III) with both extractants at a molar ratio of extractant: Sc(III) = 2.5:1 at equilibrium pH< 1.5. The plot of log D vs. log [Extractant] yield the slope (n) value as low as 1.2-1.3 and as high as n=7 at low and high extrcatant concentration level, respectively. Extraction isotherm study predicted the need of 2 stages at A: O=1:4 and A: O=1:3 using 0.1 M D2EHPA and 0.1 M Cyanex 272, respectively. Stripping of Sc (III) was carried out at varied NaOH concentration to ascertain the optimum stripping condition for effective enrichment of metal. The predicted stripping condition (2)-stages with A: O=1:3 and 1:4 for D2EHPA and Cyanex 272, respectively) obtained from Mc-Cabe Thiele plot was further validated by 6-cycles CCS study. An actual leach solution of Mg-Sc alloy bearing 1.0 g/L of Sc (III), 2.5 g/L of Mg and 0.2 M HCl was subjected for selective separation of Sc at the optimum condition. The counter current simulation (CCS) study for both extraction and stripping of actual solution resulted quantitative separation of Sc with ∼12 fold enrichment. The organic phase before and after loading of Sc (III) along with the diluents was characterized by FTIR to ascertain the phase transportation of Sc (III)

Visible light-driven H2 production over highly dispersed Ruthenia on Rutile TiO2 nanorods

The immobilization of miniscule quantities of RuO2 (~0.1%) onto one-dimensional (1D) TiO2 nanorods (NRs) allows H2 evolution from water under visible light irradiation. Rod-like rutile TiO2 structures, exposing preferentially (110) surfaces, are shown to be critical for the deposition of RuO2 to enable photocatalytic activity in the visible region. The superior performance is rationalized on the basis of fundamental experimental studies and theoretical calculations, demonstrating that RuO2(110) grown as 1D nanowires on rutile TiO2(110), which occurs only at extremely low loads of RuO2, leads to the formation of a heterointerface that efficiently adsorbs visible light. The surface defects, band gap narrowing, visible photoresponse, and favorable upward band bending at the heterointerface drastically facilitate the transfer and separation of photogenerated charge carriers.Peer ReviewedPostprint (published version

MicroRNA and other non-coding RNAs in Epstein–Barr virus-associated cancers

Simple Summary Epstein-Barr virus (EBV) is associated with a variety of malignancies. In this review, we discuss EBV-encoded microRNAs and ncRNAs and consider how their detection could aid in the diagnosis, prognostication, and monitoring of treatment in patients with EBV-associated malignancies, including classical Hodgkin's lymphoma (cHL), Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), nasopharyngeal carcinoma (NPC), and gastric carcinoma (GC). EBV is a direct causative agent in around 1.5% of all cancers. The oncogenic properties of EBV are related to its ability to activate processes needed for cellular proliferation, survival, migration, and immune evasion. The EBV latency program is required for the immortalization of infected B cells and involves the expression of non-coding RNAs (ncRNAs), including viral microRNAs. These ncRNAs have different functions that contribute to virus persistence in the asymptomatic host and to the development of EBV-associated cancers. In this review, we discuss the function and potential clinical utility of EBV microRNAs and other ncRNAs in EBV-associated malignancies. This review is not intended to be comprehensive, but rather to provide examples of the importance of ncRNAs

Exploring natural resources for sustainable management of ecosystems future challenges for control and management of Xyleborus fornicatus eichh. (Coleoptera Scolytidae), the shot-hole borer of tea in Sri Lanka

In view of the highly diverse genetic base of the seedling tea plants, though cultivated as a monocrop,along with shade trees and surrounding forests, provided a reasonably stable ecosystem then. Withthe introduction of high yielding vegetatively propagated tea during 1950's, a significant change in thedistribution and population densities of pests has been taken place. Shot-hole borer is one such pestand since then it has become the most serious and damaging pest of tea in Sri Lanka. Control hasbeen a difficult task as a result of its' wide distribution from near sea level up to 1500m amsl and theconcealed habit virtually protected from parasites and predators. Biological control usingentomopathogenic fungus, Beauvaria bassiana Vuillemin (Balsomo ) is being viewed as anenvironmentally friendly alternative to chemical control in the light of growing concern on the usage of pesticides and since oflate, the detection of pesticide residues in made tea. Preliminary investigationswere carried out with a view to find out a suitable local strain/s of the fungus for use against this pest.Laboratory studies have shown that strains of this fungus isolated from a tea garden in Talawakelle(Nuwera Eliya District) and a home garden in Welimada (Badulla District) are highly pathogenic toshot-hole borer imparting more than 90% mortality. A potential exists for using the locally availablenatural resources like entomopathogenic fungi for the management of key pests in a compatible andecologically acceptable manner. This forms the basis for Integrated Pest Management (lPM) approachof key pests. These efforts will promote and ensure the sustainable development of the tea ccosyst;m