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•Quantify some selected trace gas emissions from the active, open dumpsite.•The spatial heterogeneity of the dump surface is a critical factor for emission.•The emission hot spots/ ...areas were identified using geospatial analysis.•A considerable amount of trace gas is released from new organic waste.•The study supported to predict the trace gas emissions under similar conditions.
Karadiyana municipal solid waste (MSW) dumpsite in Colombo, Sri Lanka, has been in operation for over 30 years and was evaluated for its surface Volatile Organic Compounds (VOCs), Ammonia (NH3), and Hydrogen sulfide (H2S) emissions. Based on the surface conditions and waste characters, the dump surface was divided into eight cells, and multiple samplings were done using static flux chamber methods. The study observed that the average flux rates of VOCs, H2S, and NH3 were 137.2 ± 243.8, 6.63 ± 15.9, and 14.2 ± 16.2 mg m−2h−1 throughout the dump site. The highest average VOCs and H2S flux rates (828.6, 24.3 mg m−2h−1) were reported from new organic waste with a considerable fraction (62.5, 35.6 %) from the total emission (61.0, 3.1 Kg d−1). Leachate-flowing trenches produced the highest NH3 flux rate (36.0 mg m−2h−1), while the highest emission fraction (47.5 %) from the total (12.0 Kg d−1) was reported on old mixed waste with vegetation. The moisture content of the organic waste layers is positively correlated with these trace gas flux rates, and the NH3 flux rates depend on the pH of the surface. Results showed that the age of the waste determines the trace gas emission rate, and leachate provides an ideal pathway for landfill trace gas migration to the atmosphere. Gas collection and purification systems are essential for the initial waste dumping area and leachate treatment system. The arrangement of a proper drainage system on the dump would reduce trace gas emissions.
We evaluated the inhibitory effects of the probiotic
Lactobacillus
species on different phases of
Candida albicans
biofilm development. Quantification of biofilm growth and ultrastructural analyses ...were performed on
C. albicans
biofilms treated with
Lactobacillus rhamnosus
,
Lactobacillus casei
, and
Lactobacillus acidophilus
planktonic cell suspensions as well as their supernatants. Planktonic lactobacilli induced a significant reduction (
p
< 0.05) in the number of biofilm cells (25.5–61.8 %) depending on the probiotic strain and the biofilm phase.
L. rhamnosus
supernatants had no significant effect on the mature biofilm (
p
> 0.05), but significantly reduced the early stages of
Candida
biofilm formation (
p
< 0.01). Microscopic analyses revealed that
L. rhamnosus
suspensions reduced
Candida
hyphal differentiation, leading to a predominance of budding growth. All lactobacilli negatively impacted
C. albicans
yeast-to-hyphae differentiation and biofilm formation. The inhibitory effects of the probiotic
Lactobacillus
on
C. albicans
entailed both cell-cell interactions and secretion of exometabolites that may impact on pathogenic attributes associated with
C. albicans
colonization on host surfaces and yeast filamentation. This study clarifies, for the first time, the mechanics of how
Lactobacillus
species may antagonize
C. albicans
host colonization. Our data elucidate the inhibitory mechanisms that define the probiotic candicidal activity of lactobacilli, thus supporting their utility as an adjunctive therapeutic mode against mucosal candidal infections.
A striking and clinically relevant virulence trait of the human fungal pathogen Candida albicans is its ability to grow and switch reversibly among different morphological forms. Inhibition of ...yeast-to-hypha transition in C. albicans represents a new paradigm for antifungal intervention. We have previously demonstrated the novel antifungal activity of purpurin against Candida fungi. In this study, we extended our investigation by examining the in vitro effect of purpurin on C. albicans morphogenesis and biofilms. The susceptibility of C. albicans biofilms to purpurin was examined quantitatively by 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide reduction assay. Hyphal formation and biofilm ultrastructure were examined qualitatively by scanning electron microscopy (SEM). Quantitative reverse transcription-PCR (qRT-PCR) was used to evaluate the expression of hypha-specific genes and hyphal regulator in purpurin-treated fungal cells. The results showed that, at sub-lethal concentration (3 µg/ml), purpurin blocked the yeast-to-hypha transition under hypha-inducing conditions. Purpurin also inhibited C. albicans biofilm formation and reduced the metabolic activity of mature biofilms in a concentration-dependent manner. SEM images showed that purpurin-treated C. albicans biofilms were scanty and exclusively consisted of aggregates of blastospores. qRT-PCR analyses indicated that purpurin downregulated the expression of hypha-specific genes (ALS3, ECE1, HWP1, HYR1) and the hyphal regulator RAS1. The data strongly suggested that purpurin suppressed C. albicans morphogenesis and caused distorted biofilm formation. By virtue of the ability to block these two virulence traits in C. albicans, purpurin may represent a potential candidate that deserves further investigations in the development of antifungal strategies against this notorious human fungal pathogen in vivo.
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•Laterite and compost mixture used as effective media for filter landfill leachate.•Significantly higher filtering efficiencies show on BOD, COD, phosphate and nitrate.•Very high ...removal efficiency was reported for iron than other trace metals.•FTIR and XRD study revealed the performance of optimum filter conditions.
Landfill leachate poses environmental threats worldwide and causes severe issues on adjacent water bodies and soil by direct discharge. The primary objective of this study is to analyze the efficient use of compost and laterite mixtures (0, 10, 20, 30 and 40 wt% compost/laterite) on leachate treatment and to investigate the associated removal efficiencies under different sorption processes. Therefore, in the experimental design, laterite is used for providing adsorption characteristics, and compost for activating biological properties of the filter. The filtering process is continued until major physical changes occur in the filter at approximately 100 days. The raw leachate used for the experiment shows higher average values for many analyzed parameters. Parameters for the experiment are selected based on their availability in raw leachate in the Sri Lanka. During filtering, removal efficiencies of BOD (>90%), COD (>85%), phosphate (>90%) and nitrate (75–95%) show higher values for all filters. These removals are mainly associated with biodegradation, which is activated by the added compost. Perhaps the removal of nitrate steadily increases with time, which indicates in denitrification by the added excess carbon from the leachate. The removal of total suspended solids (TSS) is moderate to high, but conversely, the electric conductivity (EC) is unsteady, indicating an association between iron exchange and carbonate degradation. A very high removal efficiency is reported in Fe (90–100%), and wide ranges of efficiencies in Mn (30–90%), Cu (45–85%), Ni (30–93%), Cd (37–98%), Zn (15–98%), and Pb (35–98%) involve heterogeneous sorption processes. Furthermore, the normalization of raw leachate by the liquid filtrate has apparent improvements. The differences (p > .05) in removal efficiencies between the filters are significant. It can be concluded that the filter with laterite mixed with 20% of compost has the optimum conditions. Further, the Fourier-transforminfrared (FT-IR) models for filter media conclude multiple sorptions and reveal evidence on vacant sites. X-ray diffraction (XRD) analyses indicate secondary minerals gibbsite, hematite, goethite and kaolinite as the major minerals that involved on the sorption process.
In a blockchain-based system, data and the consensus-based process of recording and updating them over distributed nodes are central to enabling the trustless multi-party transactions. Thus, properly ...understanding what and how the data are stored and manipulated ultimately determines the degree of utility, performance, and cost of a blockchain-based application. While blockchains enhance the quality of the data by providing a transparent, immutable, and consistent data store, the technology also brings new challenges from a data management perspective. In this paper, we analyse blockchains from the viewpoint of a developer to highlight important concepts and considerations when incorporating a blockchain into a larger software system as a data store. The work aims to increase the level of understanding of blockchain technology as a data store and to promote a methodical approach in applying it to large software systems. First, we identify the common architectural layers of a typical software system with data stores and conceptualise each layer in blockchain terms. Second, we examine the placement and flow of data in blockchain-based applications. Third, we explore data administration aspects for blockchains, especially as a distributed data store. Fourth, we discuss the analytics of blockchain data and trustable data analytics enabled by blockchain. Lastly, we examine the data governance issues in blockchains in terms of privacy and quality assurance.
Biofilm infections are extremely hard to eradicate and controlled, triggered and controlled drug release properties may prolong drug release time. In this study, the ability to externally control ...drug release from micro and nanoparticles was investigated. We prepared micro/nanoparticles containing ciprofloxacin (CIP) and magnetic nanoparticles encapsulated in poly (lactic-co-glycolic acid) PLGA. Both micro/nanoparticles were observed to have narrow size distributions. We investigated and compared their passive and externally triggered drug release properties based on their different encapsulation structures for the nano and micro systems. In passive release studies, CIP demonstrated a fast rate of release in first 2 days which then slowed and sustained release for approximately 4 weeks. Significantly, magnetic nanoparticles containing systems all showed ability to have triggered drug release when exposed to an external oscillating magnetic field (OMF). An experiment where the OMF was turned on and off also confirmed the ability to control the drug release in a pulsatile manner. The magnetically triggered release resulted in a 2-fold drug release increase compared with normal passive release. To confirm drug integrity following release, the antibacterial activity of released drug was evaluated in Pseudomonas aeruginosa biofilms in vitro. CIP maintained its antimicrobial activity after encapsulation and triggered release.
Dark‐colored fruit berries are a rich source of polyphenols that could provide innovative bioactive molecules as natural weapons against dental caries. High‐quality extracts of cranberry, blueberry, ...and strawberry, and a combination of the three berry extracts (Orophenol), were used to treat 24‐h‐old Streptococcus mutans biofilms. The grown biofilms were treated with the berry extracts at concentrations ranging from 62.5 to 500 μg ml−1. Treated biofilms were assessed for metabolic activity, acidogenicity, biovolumes, structural organization, and bacterial viability. The biofilms treated with the cranberry and Orophenol extracts exhibited the most significant reductions in metabolic activity, acid production, and bacterial/exopolysaccharide (EPS) biovolumes, while their structural architecture appeared less compact than the control‐treated biofilms. The blueberry extract produced significant reductions in metabolic activity and acidogenicity only at the highest concentration tested, without significantly affecting bacterial/EPS biovolumes or biofilm architecture. Strawberry extracts had no significant effects on S. mutans biofilms. None of the berry extracts were bactericidal for S. mutans. The results indicate that cranberry extract was the most effective extract in disrupting S. mutans virulence properties without significantly affecting bacterial viability. This suggests a potential ecological role for cranberry phenols as non‐bactericidal agents capable of modulating pathogenicity of cariogenic biofilms.
Leptospirosis is a zoonotic illness caused by pathogenic spirochetes of the genus Leptospira. The disease spectrum ranges from a mild influenza-like presentation to a more serious Weil's syndrome. ...Leptospirosis rarely presents as a primary neurological syndrome. We report two cases of Leptospira borgpetersenii serovar Tarasssovi presenting as aseptic meningitis in Sri Lanka. Our report highlights the importance of considering leptospirosis as a differential diagnosis in patients with aseptic meningitis in endemic settings. Obtaining a detailed occupational and recreational history is helpful in diagnosing neuroleptospirosis promptly. We report the association of Leptospira borgpetersenii serovar (sv.) Tarassovi (strain bakeri) in causing aseptic meningitis, which has not been reported to the best of our knowledge.
Therapy-related acute lymphoblastic leukemia remains poorly defined due to a lack of large data sets recognizing the defining characteristics of this entity. We reviewed all consecutive cases of ...adult acute lymphoblastic leukemia treated at our institution between 2000 and 2017 and identified therapy-related cases-defined as acute lymphoblastic leukemia preceded by prior exposure to cytotoxic chemotherapy and/or radiation. Of 1022 patients with acute lymphoblastic leukemia, 93 (9.1%) were classified as therapy-related. The median latency for therapy-related acute lymphoblastic leukemia onset was 6.8 years from original diagnosis, and this was shorter for patients carrying the MLL gene rearrangement compared to those with other cytogenetics. When compared to de novo acute lymphoblastic leukemia, therapy-related patients were older (P<0.01), more often female (P<0.01), and had more MLL gene rearrangement (P<0.0001) and chromosomes 5/7 aberrations (P=0.02). Although therapy-related acute lymphoblastic leukemia was associated with inferior 2-year overall survival compared to de novo cases (46.0% vs. 68.1%, P=0.001), prior exposure to cytotoxic therapy (therapy-related) did not independently impact survival in multivariate analysis (HR=1.32; 95% CI: 0.97-1.80, P=0.08). There was no survival difference (2-year= 53.4% vs. 58.9%, P=0.68) between the two groups in patients who received allogenic hematopoietic cell transplantation. In conclusion, therapy-related acute lymphoblastic leukemia represents a significant proportion of adult acute lymphoblastic leukemia diagnoses and a subset of cases carry clinical and cytogenetic abnormalities similar to therapy-related myeloid neoplasms. Although survival of therapy-related acute lymphoblastic leukemia was inferior to de novo cases, allogeneic hematopoietic cell transplantation outcomes were comparable for the two entities.
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