Corrosion resistant behaviour of PANI–metal bilayer coatings

The present work discusses on the corrosion resistant behaviour of polymer metal bilayer coatings, viz. polyaniline (PANI), polyaniline–nickel (PANI–Ni), nickel–polyaniline (Ni–PANI), polyaniline–zinc (PANI–Zn) and zinc–polyaniline (Zn–PANI). The coatings were synthesized by means of cyclic voltametric method. The coatings thus obtained were uniform in nature and highly adherent to the mild steel substrate. The effectiveness of the coatings in preventing corrosion was tested by electrochemical impedance studies (EIS) using Nyquist and Bode plots and potentiodynamic polarization studies as well. Among the various coatings synthesized, the PANI–Zn coating was found to offer the maximum protection, followed by PANI–Ni coatings. Metal–PANI coatings were found to offer the least resistance to corrosion. The coatings thus obtained were characterized by scanning electron microscopic (SEM) analysis and the results are discussed

PHYSICOCHEMICAL CHARACTERISTICS OF RASAMANIKYA-AN AYURVEDIC ARSENICAL FORMULATION

Objective: The objective of this study was standardization and Chemical characterization of rasamanikya prepared as per standard operating procedures (SOP) mentioned in the classical text. Methods: Rasamanikya was prepared by putting churnodaka shodhita haratala (Orpiment-As2S3) between two abhraka (white mica) sheets which are heated for a while to obtain a red colored finished product. The Ayurvedic specifications for the analysis of rasamanikya were performed through qualitative and quantitative analysis. Physicochemical analysis, assay of elements by atomic absorption spectrometer (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) were carried out and some other tests such as x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray analyzer (EDAX) were also performed to ensure the quality of the drug. Results: In the finished drug Arsenic and Sulphur are present in the form of As4S4, As2S3, As2S5. On the basis of XPS survey scans, scanning electron microscopy-energy dispersive x-ray analyzer (SEM-EDAX) and carbon, hydrogen, nitrogen, sulphur (CHNS) analysis the Arsenic to Sulphur (As to S) ratio is thus standardized as 39-47: 53-61. In addition to this powder, XRD shows a major conversion into an amorphous phase. Conclusion: The results could be used to lay down a new set of pharmacopoeial standards for the preparation of rasamanikya for getting optimal efficacy of medicine. Therefore, the information will help the Scientists and Researchers to build comprehensive standards, to screen the compounds responsible for different bioactivities, and to elucidate the molecular mechanism of action

Isolation, identification and diesel-oil biodegradation capacities of indigenous hydrocarbon-degrading strains of Cellulosimicrobium cellulans and Acinetobacter baumannii from tarball at Terengganu beach, Malaysia

In this study, we isolated two indigenous hydrocarbon-degrading bacteria from tarball found in Rhu Sepuluh beach, Terengganu, Malaysia. These bacteria were identified based on their physiological characteristic and 16S rRNA gene sequence analysis, and they showed 99% similarity with Cellulosimicrobium cellulans DSM 43879 and Acinetobacter baumannii ATCC 19606 respectively. Their hydrocarbon-degrading capabilities were tested using diesel-oil as sole carbon source. Results analysed using GC–MS, showed diesel-oil alkanes were degraded an average 64.4% by C. cellulans and 58.1% by A. baumannii with medium optical density reaching 0.967 (C. cellulans) and 1.515 (A. baumannii) in minimal salt media at 32 °C for 10 days. Individual diesel-oil alkanes were degraded between 10%–95.4% by C. cellulans and 0.2%–95.9% by A. baumannii. Both strains utilized diesel-oil for growth. The study suggests both strains are part of indigenous hydrocarbon-degrading bacteria in tarball with potential for bioremediation of oil-polluted marine environment

Isolation, molecular identification and biodegradation capacities of indigenous hydrocarbon-degrading bacteria from tarball at Terengganu beach, Malaysia

In this study, we isolated four indigenous hydrocarbon-degrading bacteria from tarball found in Rhu Sepuluh beach, Terengganu, Malaysia. These bacteria were identified based on their physiological characteristic and 16S rRNA gene sequence analysis, and they showed 99% similarity with Pseudomonas stutzeri strain A1501, Pseudomonas balearica strain SP1402, Cellulosimicrobium cellulans DSM 43879 and Acinetobacter baumannii ATCC 19606 respectively. Their hydrocarbon-degrading capabilities were tested using diesel-oil as sole carbon source. Results analysed using GC-MS, showed diesel-oil alkanes were degraded an average 30.5%, 16.4%, 64.4% and 58.1% with medium optical density reaching 1.172, 1.503, 0.967 and 1.515 by Pseudomonas stutzeri, Pseudomonas balearica, Cellulosimicrobium cellulans and Acinetobacter baumannii respectively in minimal salt media at 32oC for 10 days. Individual diesel-oil alkanes were degraded between 19.7% - 49.2% (P. stutzeri), 2.5% to 27.5% (P. balearica), 10% - 95.4% (C. cellulans) and 0.2% - 95.9% (A. baumannii). All strains utilized diesel-oil for growth. The study suggests all strains are part of indigenous hydrocarbon-degrading bacteria in tarball with potential for bioremediation of oil-polluted marine environment

Green public spaces in the cities of South and Southeast Asia: Protecting needs towards sustainable well-being

The significance of green public spaces is well documented in relation to social inclusiveness, human health, and biodiversity, yet how green public spaces achieve what Gough (2017) has termed sustainable wellbeing is less understood. This contribution presents preliminary results from a study of green public spaces in four mega-cities of South and Southeast Asia: Chennai (the Republic of India), Metro Manila (the Republic of the Philippines), Singapore (the Republic of Singapore), and Shanghai (the People\u27s Republic of China), cities that have climates ranging from tropical, to subtropical and temperate. The conceptual framework brings together social practice theories with human development theories, methodological implications for the study of park usage, and Protected Needs. This study sets out to understand how parks satisfy human needs by uncovering practices in relation to activities and material arrangements. Central to the research design and sampling strategy is a desire to understand park-related practices in all of their diversity, and accounting for how different activities are carried out by diverse groups of people. The paper presents exemplary results showing that parks provide a space in which a multitude of needs are satisfied, and that parks cannot be substituted by other settings such as commercialized spaces. The paper will conclude by discussing tensions between types of park usage, and in relation to commercial encroachments on public space

Whole-Genome Sequencing to Identify Missed Rifampicin and Isoniazid Resistance Among Tuberculosis Isolates—Chennai, India, 2013–2016

India has a high burden of drug-resistant tuberculosis (DR TB) and many cases go undetected by current drug susceptibility tests (DSTs). This study was conducted to identify rifampicin (RIF) and isoniazid (INH) resistance associated genetic mutations undetected by current clinical diagnostics amongst persons with DR TB in Chennai, India. Retrospectively stored 166 DR TB isolates during 2013–2016 were retrieved and cultured in Löwenstein-Jensen medium. Whole genome sequencing (WGS) and MGIT DST for RIF and INH were performed. Discordant genotypic and phenotypic sensitivity results were repeated for confirmation and the discrepant results considered final. Further, drug resistance-conferring mutations identified through WGS were analyzed for their presence as targets in current WHO-recommended molecular diagnostics. WGS detected additional mutations for rifampicin and isoniazid resistance than WHO-endorsed line probe assays. For RIF, WGS was able to identify an additional 10% (15/146) of rpoB mutant isolates associated with borderline rifampicin resistance compared to MGIT DST. WGS could detect additional DR TB cases than commercially available and WHO-endorsed molecular DST tests. WGS results reiterate the importance of the recent WHO revised critical concentrations of current MGIT DST to detect low-level resistance to rifampicin. WGS may help inform effective treatment selection for persons at risk of, or diagnosed with, DR TB