Large-scale Synthesis and Functional Elements for the Antimicrobial Activity of Defensins

Human neutrophil defensins, and their analogues incorporating anionic, hydrophobic or cationic residues at the N- and C-termini, were synthesized by solid-phase procedures. The synthetic defensins were examined for their microbicidal activity against Candida albicans, two Gram-negative bacteria (Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis) and two Gram-positive bacteria (Streptococcus gordonii and Streptococcus mutans). The human neutrophil peptide 1 (HNP1) and HNP2 were found to be potent candidacidal agents. HNP3, which differs by one amino acid at the N-terminus of its sequence, was totally inactive. The Gram-negative bacteria A. actinomycetemcomitans and P. gingivalis and the Gram-positive bacteria S. gordonii and S. mutans were insensitive to human defensins. However, the insertion of two basic residues, such as arginine, at both the N-terminus and the C-terminus of HNP2 significantly enhanced antifungal and antibacterial activity. The addition of anionic residues, such as aspartic acid, at the N- and C-termini rendered the molecule totally inactive. The presence of two hydrophobic amino acids, such as valine, at the N-terminus of HNP2 and of two basic arginine residues at its C-terminus resulted in molecules that were optimally active against these oral pathogens. The results suggest that the N- and C-terminal residues in defensin peptides are the crucial functional elements that determine their microbicidal potency. The three-dimensional structure of all defensins constitutes the same amphiphilic beta-sheet structure, with the polar face formed by the N- and C-terminal residues playing an important role in defining microbicidal potency and the antimicrobial spectrum. The enhanced microbicidal activity observed for defensin peptides with two basic residues at both the N- and C-termini could be due to optimization of the amphiphilicity of the structure, which could facilitate specific interactions with the microbial membranes

A Study on the Necessity of Blended Learning in Classroom after the Pandemic Period

Rescheduling the usual elements of educational materials predominantly helps the learner to seek knowledge much easier than before. Developing e-sources is the next level of advancement in providing support for all learning categories. This study is an attempt to find out the necessity of blended learning in the classroom after the pandemic period .This study was conducted with a quantitative research design using a survey methodology to gather data about the learners’ interest among the blended learning from the sample of 50 undergraduate students in the state of Tamil Nadu, India. The necessity of updating to the present scenario is challenging the teachers to upgrade themselves and support the students. During the pandemic, the teaching and learning process is quite difficult to acquire education, but the integration of technology balances the mutuality. The core objective of this study is to examine the effects of the online mode of education among students and find out the requirements of blended learning for future education

Biodesalination: an emerging technology for targeted removal of Na+and Cl−from seawater by cyanobacteria

Although desalination by membrane processes is a possible solution to the problem of freshwater supply, related cost and energy demands prohibit its use on a global scale. Hence, there is an emerging necessity for alternative, energy and cost-efficient methods for water desalination. Cyanobacteria are oxygen-producing, photosynthetic bacteria that actively grow in vast blooms both in fresh and seawater bodies. Moreover, cyanobacteria can grow with minimal nutrient requirements and under natural sunlight. Taking these observations together, a consortium of five British Universities was formed to test the principle of using cyanobacteria as ion exchangers, for the specific removal of Na+ and Cl− from seawater. This project consisted of the isolation and characterisation of candidate strains, with central focus on their potential to be osmotically and ionically adaptable. The selection panel resulted in the identification of two Euryhaline strains, one of freshwater (Synechocystis sp. Strain PCC 6803) and one of marine origin (Synechococcus sp. Strain PCC 7002) (Robert Gordon University, Aberdeen). Other work packages were as follows. Genetic manipulations potentially allowed for the expression of a light-driven, Cl−-selective pump in both strains, therefore, enhancing the bioaccumulation of specific ions within the cell (University of Glasgow). Characterisation of surface properties under different salinities (University of Sheffield), ensured that cell–liquid separation efficiency would be maximised post-treatment, as well as monitoring the secretion of mucopolysaccharides in the medium during cell growth. Work at Newcastle University is focused on the social acceptance of this scenario, together with an assessment of the potential risks through the generation and application of a Hazard Analysis and Critical Control Points plan. Finally, researchers in Imperial College (London) designed the process, from biomass production to water treatment and generation of a model photobioreactor. This multimodal approach has produced promising first results, and further optimisation is expected to result in mass scaling of this process

ANTI-INFLAMMATORY EFFECT OF ZINGIBER OFFICINALE ON SPRAGUE DAWLEY RATS

ABSTRACTObjective: To investigate the anti-inflammatory effect of aqueous extract of Zingiber officinale on carrageenan-induced inflammation on SpragueDawley (SD) rats.Methods: SD rats were divided into six of five groups and allowed to acclimatize for 1 week. Inflammation was induced on the animal by injecting theright hand paw with carrageenan (0.1 ml of 1%). Group 1 was given normal saline and served as a control. Group 2 was fed with food and water andserved as the carrageenan control. Group 3 was given 200 mg/kg aqueous extract of ginger, Group 4 with 400 mg/kg aqueous extract of ginger, andGroup 5 with 150 mg/kg diclofenac sodium (reference drug for inflammation).Results: The paw edema in carrageenan-induced SD rats was considerably reduced by treating with 400 mg/kg aqueous ginger extracts whencompared to the untreated SD rats (p<0.001).Conclusion: This study indicates that aqueous extract of Z. officinale possesses anti-inflammatory properties.Keywords: Anti-inflammatory, Sprague Dawley rats, Zingiber officinale, Carrageenan, Edem

Adapting the algal microbiome for growth on domestic landfill leachate

We aimed to improve algal growth rate on leachate by optimising the algal microbiome. An algal-bacterial consortium was enriched from landfill leachate and subjected to 24 months of adaptive laboratory evolution, increasing the growth rate of the dominant algal strain, Chlorella vulgaris, almost three-fold to 0.2 d^−1. A dramatic reduction in nitrate production suggested a shift in biological utilisation of ammoniacal-N, supported by molecular 16S rRNA taxonomic analyses, where Nitrosomonas numbers were not detected in the adapted consortium. A PICRUSt approach predicted metagenomic functional content and revealed a high number of sequences belonging to bioremediation pathways, including degradation of aromatic compounds, benzoate and naphthalene, as well as pathways known to be involved in algal-bacterial symbiosis. This study enhances our understanding of beneficial mechanisms in algal-bacterial associations in complex effluents, and ultimately enables the bottom-up design of optimised algal microbiomes for exploitation within industry

Active Data Replication in Cloud to Enhance the Availability of Popular Facts

Data replication is a method to improve the performance of the data access in distributed systems. Dynamic replication is a replication that adapts replication configuration with the change of user behavior during the time to ensure the benefits of replication. Availability can be enhanced by replicating and maintaining popular data in various servers depending upon the access pattern of the end users. Finalizing the number of and location of replica servers has become a research dispute in the emerging cloud computing scenario. Since it was a constantly changing factor, an active replica management strategy is highly required that would scheme an appropriate quantity of copies to satisfy realistic system requirements and introducing replica servers within data nodes in a fair technique. It needs examining the relationship between replica count and method availability, appraising and recognizing popular data then initiate replica management process on reaching dynamic threshold limits. As a result of the proposed method, increase the availability, performance, reduce user waiting time and also reduce the execution time of the system

A double-blind study of oral salbutamol supplement and repeat sputum smear microscopy in enhancing diagnosis of smear-negative tuberculosis in south India

Background: As routine culture facilities are not available in TB control programme in low income countries like India, there is an urgent need to improve the sensitivity of sputum microscopy, especially in diagnosis of smear negative pulmonary TB. Methodology: In a double blind placebo controlled study, the role of repeat sputum microscopy after antibiotics and oral salbutamol supplement in improving the diagnosis of smear negative TB suspects was investigated in an urban TB clinic. We undertook culture examinations for all study patients to find out proportions of TB cases in this series. Results: Of 206 enrolled, (101 salbutamol (S), 105 placebo (P) groups) 26 were positive by repeat sputum smear examination; similar in two groups (S 16, P 10, p = 0.25). In all, 40 (S 23, P 17) including 26 smear- positives, were culture -positive for M. tuberculosis. Conclusions: Two thirds of initially smear negative but culture positive TB patients were smear positive on repeat sputum examination. Thus, repeat sputum smear microscopy for TB suspects improved the diagnosis, nevertheless oral salbutamol therapy was not beneficial. In resource poor settings, repeat sputum smear microscopy after a trial of antibiotics, could significantly improve the diagnosis of smear-negative PTB patients

Enumeration of sulphate-reducing bacteria for assessing potential for hydrogen sulphide production in urban drainage systems

Urban drainage structures have increasing demands which can lead to increasing hydrogen sulphide related problems forming in places where they have not previously been prevalent. This puts pressure on the methods currently used to monitor and diagnose these problems and more sophisticated methods may be needed for identifying the origin of the problems. Molecular microbiological techniques, such as quantitative polymerase chain reaction, offer a potential alternative for identifying and quantifying bacteria likely to be causing the production of hydrogen sulphide, information that when combined with an appropriate sampling programme, can then be used to identify the potentially most effective remediation technique. The application of these methods in urban drainage systems is however, not always simple, but good results can be achieved. In this study hydrogen sulphide producing bacteria were quantified in three small combined sewer overflow storage tanks. Bacterial counts were compared between wastewater, biofilms and sediments. Similar numbers were found in the wastewater and biofilms, with the numbers in the sediments being lower. If remediation methods for hydrogen sulphide is deemed necessary in the tanks, methods that target both the wastewater and the biofilms should therefore be considered

Regeneration of cellulose acetate nanofibrous mat from discarded cigarette butts

Cellulose acetate present in the cigarette butts has beenregenerated into nanofibrous mat. The developed mat is thencharacterized using various analytical tools. Uniform bead-freecellulose acetate fibre is obtained at 12 % w/v concentration ofcellulose acetate. The mat thus obtained exhibits goodantimicrobial property