Novel hydrothermal synthesis of MoS2nanocluster structure for sensitive electrochemical detection of human and environmental hazardous pollutant 4-aminophenol

A trace level electrochemical detection platform for the determination of environmentally hazardous pollutant 4-aminophenol at MoS₂nanoclusters is reported.

Nanostructured Anodic Multilayer Dielectric Stacked Metal-Insulator-Metal Capacitors

This paper presents the fabrication of Al2O3/TiO2/Al2O3 metal-insulator-metal (MIM) capacitor using anodization technique. High capacitance density of > 3.5 fF/μm2, low quadratic voltage coefficient of capacitance of < 115 ppm/V2 and a low leakage current density of 4.457 x 10(-11) A/cm2 at 3 V are achieved which are suitable for analog and mixed signal applications. We found that the anodization voltage played a major role in electrical and structural properties of the thin film. This work suggests that the anodization method can offer crystalline multilayer dielectric stack required for high performance MIM capacitor.

Isolation, purification, and characterization of avian antimicrobial glycopeptide from the posterior salivary gland of Sepia pharaonis

A proteinaceous glycopeptide was isolated from the posterior salivary gland (PSG) of Sepia pharaonis by gel (Sephadex G-100) filtration chromatography and purified by reversed-phase high-performance liquid chromatography (RP-HPLC). Among the collected fractions, fraction 12 showed a retention time (RT) of 31 min. The total protein and neutral sugar contents of the purified glycopeptide were recorded as 68.14 and 2.95 mg, respectively. The molecular weight of the purified glycopeptide was found to be ~50 kDa. The infrared (IR) and circular dichroism (CD) spectroscopy confirmed the presence of peptide and secondary structure in the purified glycopeptide. The antibacterial activity of the purified glycopeptide against avian bacterial strains was also determined. Gas chromatography-mass spectrometry (GC-MS) of the purified glycopeptide revealed the likely compounds for the antibacterial activity such as 22, 23-dibromostigmasterol acetate, 3-methyl 2-(2-oxypropyl) furan, and 2,4,4-trimethyl-3-hydroxymethyl-5A-(3-methyl-but-2-enyl)-cyclohexene. These three compounds found in the purified glycopeptide could be responsible for the antibacterial activity against the avian pathogens. The results of this study suggest that the purified glycopeptide from the PSG of S. pharaonis could be an antibacterial agent against avian bacterial pathogens.

Nanostructured bilayer anodic TiO2/Al2O3 metal-insulator-metal capacitor

This paper presents the fabrication of high performance bilayer TiO2/Al2O3 Metal-Insulator-Metal capacitor using anodization technique. A high capacitance density of 7 fF/microm2, low quadratic voltage coefficient of capacitance of 150 ppm/V2 and a low leakage current density of 9.1 nA/cm2 at 3 V are achieved which are suitable for Analog and Mixed signal applications. The influence of anodization voltage on structural and electrical properties of dielectric stack is studied in detail. At higher anodization voltages, we have observed the transformation of amorphous to crystalline state of TiO2/Al2O3 and improvement of electrical properties.

Abundance, species composition of microzooplankton from the coastal waters of Port Blair, South Andaman Island

BACKGROUND

Microzooplankton consisting of protists and metazoa <200 μm. It displays unique feeding mechanisms and behaviours that allow them to graze cells up to five times their own volume. They can grow at rates which equal or exceed prey growth and can serve as a viable food source for metazoans. Moreover, they are individually inconspicuous, their recognition as significant consumers of oceanic primary production. The microzooplankton can be the dominant consumers of phytoplankton production in both oligo- and eutrophic regions of the ocean and are capable of consuming >100% of primary production.

RESULTS

The microzooplankton of the South Andaman Sea were investigated during September 2011 to January 2012. A total of 44 species belong to 19 genera were recorded in this study. Tintinnids made larger contribution to the total abundance (34%) followed in order by dinoflagellates (24%), ciliates (20%) and copepod nauplii (18%). Foraminifera were numerically less (4%). Tintinnids were represented by 20 species belong to 13 genera, Heterotrophic dinoflagellates were represented by 17 species belong to 3 genera and Ciliates comprised 5 species belong to 3 genera. Eutintinus tineus, Tintinnopsis cylindrical, T. incertum, Protoperidinium divergens, Lomaniella oviformes, Strombidium minimum were the most prevalent microzooplankton. Standing stock of tintinnids ranged from 30-80 cells.L-1 and showed a reverse distribution with the distribution of chlorophyll a relatively higher species diversity and equitability was found in polluted harbour areas.

CONCLUSIONS

The change of environmental variability affects the species composition and abundance of microzooplankton varied spatially and temporarily. The observations clearly demonstrated that the harbor area differed considerably from other area in terms of species present and phytoplankton biomass. Further, the phytoplankton abundance is showed to be strongly influenced by tintinnid with respect to the relationship of prey-predator. Consequently, further investigation on microzooplankton grazing would shed light on food web dynamics.

Fatal cerebral abscess caused by Cladophialophora bantiana

Primary cerebral phaeohyphomycosis is caused by pigmented fungi that exhibit distinct neurotropism often in immunocompetent individuals. A 20-yr-old male presented with multiple brain abscess which was subsequently proven microbiologically to be due to Cladophialophora Bantiana. In spite of near total excision and appropriate antifungal agents succumbed to his illness. We report this case to highlight its rarity and high mortality in an immunocompetent host. There is no initial clinical or laboratory feature that makes a preoperative diagnosis possible and relies on microbiological confirmation.

Angioplasty and stenting of solitary supra-aortic artery and aortoplasty by kissing balloon technique

A child presented with symptoms of compromise to cerebral blood flow and cardiac failure. On diagnostic angiography, he was found to have a discrete coarctation and related ostial stenosis of the left subclavian artery, which acted as the sole source of cerebral blood flow. The subclavian lesion was initially dilated with a 6 mm x 50 mm balloon. The discrete coarctation was then dilated with an 8 mm x 50 mm balloon. Since significant residual stenosis was present at the subclavian origin, it was stented with a 20 mm Palmaz-Schatz stent (Cordis Corporation, Miami Lakes, Florida). Since the coarcted segment required further dilatations, the kissing balloon technique was used, wherein the 6 mm balloon was placed extending from the left subclavian lesion distally to the related aortic lesion proximally, along with another 10 mm balloon in the aorta. The end result was acceptable and the patient's symptoms improved significantly after the procedure.