Browsing by Author "Dassanayake, B."

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Idiopathic pancreatitis is a consequence of an altering spectrum of bile nucleation time
(Biomed Central, 2011) Abeysuriya, V.; Deen, K.I.; Dassanayake, B.; Kumarage, S.; Navarathne, N.; Pathirana, A.
BACKGROUND: The pathogenesis of idiopathic pancreatitis (IP) remains poorly understood. Our hypothesis is that IP is a sequel of micro-crystallization of hepatic bile. METHODS: A prospective case control study compared 55 patients; symptomatic cholelithiasis - 30 (14 male, median age 36 years; mean BMI - 25.1 kg/m2), gallstone pancreatitis - 9 (3 male, median age 35 years; mean BMI - 24.86 kg/m2 ) and IP - 16 (9 male, median age 34 years; mean BMI -23.34 kg/m2) with 30 controls (15 male, median age 38 years; mean BMI = 24.5 kg/m2) undergoing laparotomy for conditions not related to the gall bladder and bile duct. Ultrafiltered bile from the common hepatic duct in patients and controls was incubated in anaerobic conditions and examined by polarized light microscopy to assess bile nucleation time (NT). In the analysis, the mean NT of patients with gallstones and gallstone pancreatitis was taken as a cumulative mean NT for those with established gallstone disease (EGD). RESULTS: Patients were similar to controls. Mean NT in all groups of patients was significantly shorter than controls (EGD cumulative mean NT, 1.73 +/- 0.2 days vs. controls, 12.74 +/- 0.4 days, P = 0.001 and IP patients mean NT, 3.1 +/- 0.24 days vs. controls, 12.74 +/- 0.4 days, P = 0.001). However, NT in those with IP was longer compared with those with EGD (mean NT in IP, 3.1 +/- 0.24 days vs. cumulative mean in EGD: 1.73 +/- 0.2 days, P = 0.002). CONCLUSION: Nucleation time of bile in patients with IP is abnormal and is intermediate to nucleation time of lithogenic bile at one end of the spectrum of lithogenicity and non-lithogenic bile, at the other end
Thermally evaporated CdS/CdTe thin film solar cells: Optimization of CdCl2 evaporation treatment on absorber layer
(Current Applied Physics, 2022) Kumarasinghe, R.; Kumarasinghe, P.; Wijesundera, R.; Dassanayake, B.
CdCl2 treatment is crucial in the fabrication of highly efficient CdS/CdTe thin-film solar cells. This study reports a comprehensive analysis of thermal evaporated CdS/CdTe thin-film solar cells when the CdTe absorber layer is CdCl2 annealed at temperatures from 340 to 440 ◦C. Samples were characterized for structural, optical, morphological and electrical properties. The films annealed at 400 ◦C showed better crystallinity with a cubic zinc blende structure having large grains. Higher refractive index, optical conductivity, and absorption coefficient were recorded for the CdTe films annealed at 400 ◦C with CdCl2. Optimum photoactive properties for CdS/ CdTe thin-film solar cells were also obtained when samples were annealed at 400 ◦C for 20 min with CdCl2, and the best device exhibited VOC of 668.4 mV, JSC of 13.6 mA cm􀀀 2, FF of 53.9% and an efficiency of 4.9%.
Young patients with colorectal cancer have poor survival in the first twenty months after operation and predictable survival in the medium and long-term: analysis of survival and prognostic markers
(BioMed Central, 2010) Chan, K.K.; Dassanayake, B.; Deen, R.; Wickramarachchi, R.E.; Kumarage, S.K.; Samita, S.; Deen, K.I.
OBJECTIVES: This study compares clinico-pathological features in young (<40 years) and older patients (>50 years) with colorectal cancer, survival in the young and the influence of pre-operative clinical and histological factors on survival. MATERIALS AND METHODS: A twelve-year prospective database of colorectal cancer was analysed. Fifty-three young patients were compared with forty-seven consecutive older patients over fifty years old. An analysis of survival was undertaken in young patients using Kaplan Meier graphs, non-parametric methods, Cox's Proportional Hazard Ratios and Weibull Hazard models. RESULTS: Young patients comprised 13.4 percent of 397 with colorectal cancer. Duration of symptoms and presentation in the young was similar to older patients (median, range; young patients; 6 months, 2 weeks to 2 years, older patients; 4 months, 4 weeks to 3 years, p > 0.05). In both groups, the majority presented without bowel obstruction (young--81%, older--94%). Cancer proximal to the splenic flexure was present more in young than in older patients. Synchronous cancers were found exclusively in the young. Mucinous tumours were seen in 16% of young and 4% of older patients (p < 0.05). Ninety-four percent of young cancer deaths were within 20 months of operation. At median follow up of 50 months in the young, overall survival was 70% and disease free survival 66%. American Joint Committee on Cancer (AJCC) stage 4 and use of pre-operative chemoradiation in rectal cancer was associated with poor survival in the young. CONCLUSION: If patients, who are less than 40 years old with colorectal cancer, survive twenty months after operation, the prognosis improves and their survival becomes predictable.