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1.
Chemosphere ; 288(Pt 2): 132551, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34655645

RESUMO

Biochar has widely been utilized as an agricultural soil amendment owing to its enhanced surface properties and cost-effectiveness. In the present work, the influence of tea waste biochar (TWBC) upon acid modification on Allium cepa L. (red onion) growth has been studied. Its effect as a soil amendment has also been studied by assessing the nutrient retention, microbial population growth and immobilization of potentially toxic metal ions. A greenhouse experiment was carried out by applying different biochar (BC) ratios (2% and 5% w/w) to soil as the growth media for onion plants. A 2.4 times (2.4 × ) reduction of phosphate from leaching was observed upon BC application at a ratio of 2% than that of 5%. Moreover, red onion plants that grew in the BC-fertilizer amended soil at a 2% ratio showed higher growth compared to that of 5%. A ∼1.3 × and ∼1.2 × increment of total dry weight was observed upon amendment of soil fertilizer system with nitric and sulfuric acid-modified TWBC, respectively. An analysis of the potentially toxic metal ion uptake by the respective plant parts showed that lead uptake by the roots of red onion was ∼8.3 × less in BC amended soil compared to that in contaminated soil. Thus, acid-modified TWBC can be considered a potential soil amendment for an enhanced red onion growth. Employing TWBC as a soil amendment in tropical countries, where tea-waste is in abundance, will boost sustainable agriculture.


Assuntos
Cebolas , Chá , Carvão Vegetal
2.
Artigo em Inglês | MEDLINE | ID: mdl-34574538

RESUMO

Evidence of associations between exposure to ambient air pollution and health outcomes are sparse in the South Asian region due to limited air pollution exposure and quality health data. This study investigated the potential impacts of ambient particulate matter (PM) on respiratory disease hospitalization in Kandy, Sri Lanka for the year 2019. The Generalized Additive Model (GAM) was applied to estimate the short-term effect of ambient PM on respiratory disease hospitalization. As the second analysis, respiratory disease hospitalizations during two distinct air pollution periods were analyzed. Each 10 µg/m3 increase in same-day exposure to PM2.5 and PM10 was associated with an increased risk of respiratory disease hospitalization by 1.95% (0.25, 3.67) and 1.63% (0.16, 3.12), respectively. The effect of PM2.5 or PM10 on asthma hospitalizations were 4.67% (1.23, 8.23) and 4.04% (1.06, 7.11), respectively (p < 0.05). The 65+ years age group had a higher risk associated with PM2.5 and PM10 exposure and hospital admissions for all respiratory diseases on the same day (2.74% and 2.28%, respectively). Compared to the lower ambient air pollution period, higher increased hospital admissions were observed among those aged above 65 years, males, and COPD and pneumonia hospital admissions during the high ambient air pollution period. Active efforts are crucial to improve ambient air quality in this region to reduce the health effects.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Idoso , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , China , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Hospitalização , Humanos , Masculino , Material Particulado/análise , Material Particulado/toxicidade , Sri Lanka/epidemiologia
3.
Int J Dent ; 2020: 9752925, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32724307

RESUMO

MATERIALS AND METHODS: Fifty-seven final-year dental students in the year 2019 and the first edentulous patient managed by them were recruited for the study. A fourteen-item questionnaire was given to the students to assess their level of confidence just before commencement of the treatment. Questionnaire for the patients was used to assess their satisfaction both with the operator and the dentures. Clinical outcome of dentures was assessed using ten criteria. RESULTS: The average confidence level of the students was found to be 2.17 in a 4-point scale. A two-sample test indicated that there is a significant difference in the overall level of confidence between female and male students (p value = 0.004). Moreover, a nonparametric correlation analysis revealed that there is no significant correlation between the overall level of confidence of each student and patient satisfaction regarding student performance, level of satisfaction of patients regarding dentures, and the quality of dentures as assessed by the clinicians (p value = 0.545, 0.877, and 0.801, respectively). CONCLUSIONS: Students' level of confidence in carrying out complete denture procedures is satisfactory. Male students exhibited a better overall level of confidence than female students. However, the level of confidence exhibited by the dental students does not predict patient satisfaction or clinical outcome.

4.
RSC Adv ; 9(31): 17612-17622, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-35520596

RESUMO

Tea-waste is an abundant feedstock for producing biochar (BC) which is considered to be a cost effective carbonaceous adsorbent useful for water remediation and soil amendment purposes. In the present study, tea-waste BC (TWBC) produced at three different temperatures were subjected to nitric, sulfuric and hydrochloric acid modifications (abbreviated as NM, SM and HM respectively). Characteristics of the raw and modified BC such as ultimate and proximate analyses, surface morphology, surface acidity and functionality, point of zero charge, cation exchange capacity (CEC) and thermal stability were compared to evaluate the influence of pyrolysis temperature and of modifications incorporated. The amount of carboxylic and phenolic surface functionalities on TWBC was seen to decrease by 93.44% and 81.06% respectively when the pyrolysis temperature was increased from 300 to 700 °C. Additionally, the yield of BC was seen to decrease by 46% upon the latter temperature increment. The elemental analysis results provided justification for high-temperature BC being more hydrophobic as was observed by the 61% increase in H/C ratio which is an indication of augmented aromatization. The CEC was the highest for the low-temperature BC and was seen to further increase by NM which is attributed to the 81.89% increase in carboxylic functionalities. The surface area was seen to significantly increase for BC700 upon NM (∼27 times). The SM led to pore wall destruction which was observed in scanning electron microscopy images. Findings would enable the rational use of these particular modifications in relevant remediation and soil amendment applications.

5.
J Dent Educ ; 82(8): 898-904, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30068780

RESUMO

Even though the traditional live demonstration method is commonly used in teaching laboratory techniques to dental students, it has many drawbacks. The aim of this study was to assess the acquisition of knowledge, practical skills, and perceptions of dental students who had a live demonstration versus procedural video on arranging artificial teeth. All 79 third-year dental students at a dental school in Sri Lanka, who had no previous experience in arrangement of teeth, were randomly divided into two groups in 2016. Students in group 1 had a live demonstration, while students in group 2 had a video demonstration. A pretest and posttest were conducted to assess the students' knowledge about arrangement of teeth. After one week, students in both groups were requested to arrange teeth, and a practical skills score was given. Following this, a questionnaire was used to assess the students' perceptions regarding their method of learning. Three students in group 1 did not attend the live demonstration, so the results were based on 76 participants: group 1 n=36, group 2 n=40. The results showed no significant difference between the two group's mean pretest scores (p=0.460). However, group 2 showed a statistically significant increase in mean posttest score over its pretest score (p=0.002). This difference was not seen in group 1. There was no significant difference in the mean skills test score for the two groups (p=0.588). These results suggest the procedural video was as good as the live demonstration in teaching the specific task selected for this study. However, when the perceptions of the two groups were compared, the students considered the video as a better teaching tool except when clarification was needed.


Assuntos
Competência Clínica , Educação em Odontologia/métodos , Percepção , Estudantes de Odontologia/psicologia , Ensino , Gravação em Vídeo , Avaliação Educacional , Feminino , Humanos , Aprendizagem , Masculino , Sri Lanka
6.
J Investig Clin Dent ; 9(2): e12293, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28862373

RESUMO

AIM: The aim of the present study was to investigate the sociodemographic profile and oral health status (Decayed, Missing, Filled Teeth [DMFT] and periodontal health) of thalassemic patients compared to healthy individuals. METHODS: The data were collected by means of an interviewer-administered, pretested, and validated questionnaire, followed by oral examination. Patients attending the outpatient department, who were age and sex matched, but without any diagnosed or suspected long-term illnesses, were considered for the control group. Both groups were compared in terms of facial profile, skeletal pattern, facial angles, DMFT, and periodontal health (plaque index, bleeding on probing, and probing pocket depth). RESULTS: The association of convex facial profile and class II skeletal pattern with Thalassemic status was statistically significant when compared to healthy individuals. Decayed, missing, and filled teeth in the permanent and deciduous dentition, plaque index, and probing pocket depths of the control group were significantly higher compared with the thalassemic group. Surprisingly, 67.8% of thalassemic patients did not show bleeding on probing. CONCLUSION: Families of the thalassemic patients attending the National Thalassaemia Centre are from a low socioeconomic background. Their DMFT and periodontal health are significantly better than those of healthy individuals.


Assuntos
Saúde Bucal , Classe Social , Talassemia/epidemiologia , Estudos de Casos e Controles , Criança , Estudos Transversais , Índice CPO , Demografia , Feminino , Humanos , Masculino , Índice Periodontal , Fatores de Risco , Sri Lanka/epidemiologia , Inquéritos e Questionários
7.
Artigo em Inglês | MEDLINE | ID: mdl-19062694

RESUMO

A total of 460 samples (serum or plasma) were obtained from clinically diagnosed liver disease patients from January 2006 to December 2007 and subjected to reverse transcription--polymerase chain reaction (RT-PCR) based detection of HCV. Of these, 32 samples (6.9%) were positive for HCV RNA. Samples that were positive for HCV were genotyped with type specific primers. The genotyping assay was validated by DNA sequencing and phylogenetic analysis. The Sri Lankan isolates were comprised predominantly of genotype 1b (46.9%) followed by genotype 2b (21.9%), 2a (15.6%) and mixed infection with genotypes 1b and 2b (3.1%). This is the first report of the distribution of HCV genotypes in Sri Lanka.


Assuntos
Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C/virologia , Genótipo , Humanos , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sri Lanka
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