Liquid-phase microextraction-gas chromatography-mass spectrometry for the determination of bromate, iodate, bromide and iodide in high-chloride matrix.

In the determination of bromate and iodate, any free bromide and iodide present was quantitatively removed by anion exchange with silver chloride exploiting the differences in silver salts solubility product, being AgCl, 1.8 x 10(-10), AgBr, 5.0 x 10(-13), AgI, 8.

Optimization of experimental parameters in single-drop microextraction-gas chromatography-mass spectrometry for the determination of periodate by the Malaprade reaction, and its application to ethylene glycol.

The aim of present work was to optimize the experimental parameters in single drop microextraction under solution immersion (SDME) and headspace (HS-SDME) extraction modes for the determination of periodate using guaifenesine [3-(2'-methoxyphenoxy)-1,2-propane diol] and norephedrine (phenylpropanolamine) as new and alternative reagents for the Malaprade reaction. The reactions were complete within 5min resulting in the formation of 2-(2'-methoxyphenoxy)-acetaldehyde and benzaldehyde, respectively. SDME/HS-SDME of oxidation products with 2mul of anisole or 1mul of toluene, respectively, has permitted the determination of periodate at mugl(-1) concentration levels.

First case of cryptococcosis in a new species of bandicoot (Bandicota indica) caused by Cryptococcus neoformans var. grubii.

The first case of cryptococcosis caused by Cryptococcus neoformans var. grubii in a new species of bandicoot (Bandicota indica) is described. The animal was trapped in a bamboo thicket in a park located in the city of Jabalpur, India.

Preparation, characterization and microhardness study of semi interpenetrating polymer networks of polyvinyl alcohol and crosslinked polyacrylamide.

Semi-IPNs based on polyvinyl alcohol (PVA) and crosslinked polyacrylamide (PAM) were prepared and characterized. Various compositions of semi-interpenetrating polymer networks (semi-IPNs) were prepared by varying concentrations of PVA, acrylamide (AM) and crosslinker N,N'-methylene bis acrylamide (MBA) in the feed mixtures and polymerized using a suitable redox system comprising of potassium persulphate and metabisulphite. The prepared semi-IPNs were characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods.

Catalytic and regulatory properties of sulphur metabolizing enzymes in cyanobacterium Synechococcus elongatus PCC 7942.

Synechococcus elongatus PCC 7942 was able to grow with several S sources. The sulphur metabolizing enzymes viz. ATP sulphurylase, cysteine synthase, thiosulphate reductase and L- and D-cysteine desulphydrases were regulated by sulphur sources, particularly by sulphur amino acids and organic sulphate esters.

Screening and selection of most potent diazotrophic cyanobacterial isolate exhibiting natural tolerance to rice field herbicides for exploitation as biofertilizer.

Periodic applications of heavy dosages of herbicides in modern rice-agriculture are a necessary evil for obtaining high crop productivity. Such herbicides are not only detrimental to weeds but biofertilizer strains of diazotrophic cyanobacteria also. It is therefore, essential to screen and select such biofertilizer strains of diazotrophic cyanobacteria exhibiting natural tolerance to common rice-field herbicides that can be further improved by mutational techniques to make biofertilizer technology a viable one.

Internal Transcribed Spacer (ITS) of rDNA of appendaged and non-appendaged strains of Microsporum gypseum reveals Microsporum appendiculatum as its synonym.

Recently a new taxon of geophilic dermatophytes was established as Microsporum appendiculatum Bhat and Mariam, based on the presence of appendaged macroconidia. However, such appendages are already known in the related species Microsporum gypseum. We conducted a survey of soil in central India as a part of a microbial biodiversity project and obtained two strains of M.

Characterization of proteases in guts of Daphnia magna and their inhibition by Microcystis aeruginosa PCC 7806.

Many cyanobacteria produce peptides that inhibit mammalian proteases. The hypothesis that inhibitors of mammalian proteases produced by cyanobacteria also interfere with digestive proteases of natural cladoceran grazers was tested by comparing the effects of cyanobacterial protease inhibitors on digestive proteases from Daphnia magna and on commercially available bovine proteases. The major digestive proteases of D.

Cysteine and serine protease-mediated proteolysis in body homogenate of a zooplankter, Moina macrocopa, is inhibited by the toxic cyanobacterium, Microcystis aeruginosa PCC7806.

The paper describes the characterization of proteases in the whole body homogenate of Moina macrocopa, which can possibly be inhibited by the extracts of Microcystis aeruginosa PCC7806. With the use of oligopeptide substrates and specific inhibitors, we detected the activities of trypsin, chymotrypsin, elastase and cysteine protease. Cysteine protease, the predominant enzyme behind proteolysis of a natural substrate, casein, was partially purified by gel filtration.

Single drop microextraction or solid phase microextraction-gas chromatography-mass spectrometry for the determination of iodine in pharmaceuticals, iodized salt, milk powder and vegetables involving conversion into 4-iodo-N,N-dimethylaniline.

A rapid sequence of oxidation and iodination using 2-iodosobenzoate as an oxidizing agent and N,N-dimethylaniline as an iodine scavenger at pH 6.4, when 4-iodo-N,N-dimethylaniline is formed, has been used for the determination of iodide by GC-MS. Solid phase microextraction (SPME) and single drop microextraction (SDME) have been used for the extraction of the iodo-derivative and their relative efficiencies compared.

Prevalence & distribution of aeromonads in different chlorinated water samples.

Four different sites were selected for sampling of water samples--river, pond, hand-pump, and municipal water. These were analyzed for physico-chemical and bacteriological parameters with special reference to aeromonads following standard methods. Chlorinated disinfectants in the form of powder and liquid (drops) were used for the treatment.

Determination of aromatic primary amines at microg l(-1) level in environmental waters by gas chromatography-mass spectrometry involving N-allyl-n'-arylthiourea formation and their on-line pyrolysis to aryl isothiocyanates.

Derivatization of aromatic primary amines to N-allyl-N'-arylthioureas by reaction with allyl isothiocyanate and GC-MS of the derivatives, when pyrolysis to aryl isothiocyanates occurs in the heated injector, has been used to determine aromatic amines in the range 0.5-50 microg l(-1) with a correlation coefficient, r, in the range 0.9902-0.

In vitro degradation of keratin by two species of Bacillus.

The ability of two species of Bacillus to degrade child's scalp hair, cow horn, cow hooves, and human nails in vitro under static conditions was studied by the determination of soluble sulphhydryl compounds as cysteine, disulphides as cystine, and release of extracellular keratinase along with changes in alkalinity of the culture filtrate. Child's scalp hair was found to be the most favored keratin substrate for Bacillus spp.

Nutrients and pH regulate algicide accumulation in cultures of the cyanobacterium Oscillatoria laetevirens.

• The change in algicide synthesis in response to nutrients and pH in axenic cultures of the planktonic cyanobacterium, Oscillatoria laetevirens is reported. • Analytical and bioassay techniques were used to determine the effects of nitrogen (N), sulpher (S), phosphorus (P), magnesium (Mg ), calcium (Ca ) and hydrogen (H ) on Oscillatoria laetevirens growth, secondary metabolite accumulation and minimum inhibitory concentration in culture filtrates. • Growth and secondary metabolite production were affected by nutrient addition.

Calculation of pulsed NMR signal in I = 3/2 quadrupolar spin system.

The rf pulse response of I = 3/2 spin system experiencing first order quadrupolar splitting is studied using density matrix approach. A general expression is derived in terms of spin populations, quadrupole splitting and duration and amplitude of the rf pulse for calculating the NMR signal arising due to the centre line and satellite resonances for the situation where the impressed rf pulse excites the resonances selectively as well as non-selectively. The necessary 4 X 4 transformation matrix obtained analytically by diagonalyzing the Hamiltonian are used to get the expression for the centre line response.

Determination of iodide by derivatization to 4-iodo-N,N-dimethylaniline and gas chromatography-mass spectrometry.

A real-time determination of iodide is proposed which involves the oxidation of iodide with 2-iodosobenzoate in the presence of N,N-dimethylaniline. The reaction is completed within 1 min to yield 4-iodo-N,N-dimethylaniline, which is extracted in cyclohexane and determined by GC-MS. It was also possible to determine iodine by derivatization in the absence of 2-iodosobenzoate, and iodate by its reduction with ascorbic acid to iodide and subsequent derivatization.

Experimental aspergillosis in the German cockroach Blattella germanica: a histopathological study.

Inoculation of a spore suspension of Aspergillus flavus in the haemocoel of the German cockroach (Blatella germanica) resulted in large-scale invasion of various internal organs as seen in tissue sections stained with a fungal stain. The organs affected were the alimentary canal, fat bodies, muscle fibres, malpighian tubules and the cerebral neurosecretory cells. No invasion of the trachea and tracheoles was noted.

Aspergillosis in German cockroach Blattella germanica (L.) (Blattoidea: Blattellidae).

Natural infection of Aspergillus flavus was observed in adults of Blattella germanica. Though the adult insects exhibited no external symptoms, they became hypoactive and later died. The dead and experimentally infected insects repeatedly yielded Aspergillus flavus in culture on Czapek's medium.

Characteristics of extracellular proteases produced by Bacillus laterosporus and Flavobacterium sp. isolated from gelatinfactory effluents.

Forty bacterial isolates from the effluents of a gelatin factory (Jabalpur, India) were screened for protease activity and the two most potent producers were identified as Bacillus laterosporus and a Flavobacterium sp. The enzymes of both isolates were optimal at pH 8 and 60°C, with maximum activity after 90 min. The enzyme activity of B.

Maxillary sinusitis caused by Ascotricha chartarum Berk. (anamorph Dicyma ampullifera Boul.): a new phaeoid opportunistic human pathogen.

The first human infection caused by Ascotricha chartarum of the maxillary sinus is described. The patient, a 35-year-old woman, developed a hard bony swelling on the right cheek. Her maxillary X-ray showed complete opacity of the right maxillary antrum with a shadow of erosion.

Short communication: Protoplast formation from the thermophilic fungus Malbranchea sulfurea, using the thermostable chitinase and laminarinase of Paecilomyces varioti.

Two thermostable enzymes produced by the thermophilic fungus Paecilomyces varioti, a chitinase and laminarinase, were used to isolate protoplasts of a thermophilic fungus, Malbranchea sulfurea. The frequency of protoplast regeneration observed (35%) was considerably higher than that obtained using commercial lytic enzymes.

Two cases of cutaneous phaeohyphomycosis caused by Curvularia pallescens.

Two cases of cutaneous phaeohyphomycosis caused by Curvularia pallescens are described. Lesions were found on the feet, thigh and thumb and were irregularly marginated, pruritic black and occasionally purulent. Histopathology revealed heavy infection of the stratum corneum and other cutaneous layers as well as host tissue response.

Chronic bilateral suppurative otitis media caused by Aspergillus terreus.

A case of bilateral suppurative otitis media is described in a patient with the presenting symptoms of otorrhoea, itching, mild deafness, heaviness in the ear and otalgia. The patient had perforation in the tympanic membrane. Histological sections revealed aggregated fungal masses of Aspergillus terreus.