36 research outputs found
Sound-Speed Prediction as a Function of Temperature at Discrete Depths in the Bay of Bengal
Through regression analysis, temperature dependent relationships are developed to predict sound-speed. at discrete depths in the Bay of Bengal, thereby demonstrating the feasibility of sound-speed prediction through polynomial expressions in temperature disregarding salinity variations. A separate regression equation is develbped for the historical sound-speed and temperature data at the standard depths upto 250 m. At specific depths and in the given geographic area in the Bay of Bengal (5-8" N, 90-93" E) polynomials of temperature are proved to be a precise way to predict sound-speed
Dendrimers as a Novel Carrier in Anti-HIV Therapy
The present treatments for HIV transfection include chemical agents and gene therapies. Although many chemical drugs, peptides and genes have been developed for HIV inhibition, a variety of non-ignorable drawbacks limited the efficiency of these materials. Dendrimers has ability to carrier of antiviral drugs due to some properties such as mono-dispersity, defined structure, amenability for functionalization using diverse ligands and its low-nanometer size. In this review, we discuss the application of dendrimers as both therapeutic agents and non-viral vectors of chemical agents and genes for HIV treatment. In one way, dendrimers with functional end groups combine with the gp120 of HIV and CD4 molecule of host cell to suppress the attachment of HIV to the host cell. In another way, dendrimers are also able to transfer chemical drugs and genes into the host cells, which increase the anti-HIV activity of these materials. Dendrimers as therapeutic tools provide a potential treatment for HIV infection.
Keywords: Dendrimers, Drug release, Drug targeting, gp120, CD4, Antiviral dru
Volatile Organic Compounds Emitted by Fungal Associates of Conifer Bark Beetles and their Potential in Bark Beetle Control
Conifer bark beetles attack and kill mature spruce and pine trees, especially during hot and dry conditions. These beetles are closely associated with ophiostomatoid fungi of the Ascomycetes, including the genera Ophiostoma, Grosmannia, and Endoconidiophora, which enhance beetle success by improving nutrition and modifying their substrate, but also have negative impacts on beetles by attracting predators and parasites. A survey of the literature and our own data revealed that ophiostomatoid fungi emit a variety of volatile organic compounds under laboratory conditions including fusel alcohols, terpenoids, aromatic compounds, and aliphatic alcohols. Many of these compounds already have been shown to elicit behavioral responses from bark beetles, functioning as attractants or repellents, often as synergists to compounds currently used in bark beetle control. Thus, these compounds could serve as valuable new agents for bark beetle management. However, bark beetle associations with fungi are very complex. Beetle behavior varies with the species of fungus, the stage of the beetle life cycle, the host tree quality, and probably with changes in the emission rate of fungal volatiles. Additional research on bark beetles and their symbiotic associates is necessary before the basic significance of ophiostomatoid fungal volatiles can be understood and their applied potential realized
Distribution of mesopelagic micronekton in the Arabian Sea during the winter monsoon
227-237Response of micronekton to oxygen minimum zones in the Arabian Sea (AS)
during winter monsoon period was investigated using data of 52 trawls deployed
during four winter cruises between 1998 and 2000. Twenty-nine species,
representing 19 groups were identified in the deep scattering layer (DSL). The
mesopelagic community was dominated by shrimps, myctophids, fish larvae,
phosichthyids and leptocephalus. Based on the distribution, two regions were
distinguished: the southern Arabian Sea (sAS) and the northern Arabian Sea
(nAS). Ceratoscopelus warmingii, Diogenichthys panurgus, Diaphus fragilis,
Lampanyctus turneri, Thallasocaris carinata, Leptochela robusta, Oplophorus
typus, Viniciguria nimbaria, V.leucita were dominant in the sAS; Benthosema
pterotum, Bolinichthys longipes, Diogenichthys panurgus, D. fragilis, D.
aliciae, V. nimbaria, V. leucita were dominant in the nAS. Most of these
species were abundant in the upper 50 m during night, but were found in the
oxygen minimum zone (OMZ) between 175 to 800 m north of 13oN during daytime.
Fourteen of 29 species were detected within the OMZ during day time
SiO<sub>2</sub>-H<sub>3</sub>PO<sub>4</sub> catalyzed condensation of amines and aldehydes: Solvent-free synthesis of some <i>E</i>-imines, spectral correlations of (<i>E</i>)-<i>N</i>-(substituted benzylidene)-1-benzylpiperidin-4-amines and XRD structure of (<i>E</i>)-<i>N</i>-(4-nitrobenzylidene)-1-benzylpiperidin-4-amine<span style="mso-ansi-language:EN-GB" lang="EN-GB"> </span>
779-790A series of Schiff
bases (aryl E-imines) including (E)-N-(substituted
benzylidene)-1-benzylpiperidin-4-amines have been derived from the SiO2-H3PO4
catalyzed solvent-free condensation of aryl amines including
1-benzylpiperidin amines and substituted benzaldehydes under microwave irradiation.
The yields of the imines are more than 85%. The synthesized imines are
characterized by their physical constants, analytical and spectroscopic data
earlier reported in literature. The group frequencies of imines such as
infrared (<span style="font-family:Symbol;mso-ascii-font-family:
" times="" new="" roman";mso-hansi-font-family:"times="" roman";mso-char-type:symbol;="" mso-symbol-font-family:symbol"="" lang="EN-GB">v, cm-1), NMR both 1H
and 13C chemical shifts (<span style="font-family:
Symbol;mso-ascii-font-family:" times="" new="" roman";mso-hansi-font-family:"times="" roman";="" mso-char-type:symbol;mso-symbol-font-family:symbol"="" lang="EN-GB">, ppm)
have been correlated with Hammett substituent constants, F and R parameters.
The XRD structure of the (E)-N-(4-nitrobenzylidene)-1-benzylpiperidin-4-amine
have been established.
</span
Single dose vaccine delivery system of tetanus toxoid formulation based on chitosan microspheres
Biodegradable polymers such as Chitosan or PLGA has been used for sustain release of vaccines for prolonged period. To develop single dose vaccine delivery system of tetanus toxoid using chitosan microspheres. Different batches, 1%, 2% and 3% of chitosan microspheres (CM) were prepared by emulsion cross-linking method using glutaradehyde saturated toluene (GST). The tetanus toxoid (TT) was loaded with 1%, 2% and 3% of CM by adsorption method. Percentage of TT absorbed in 1%, 2% and 3% CM were determined by Limes flocculation method. In vitro release of adsorbed TT from 1%, 2% and 3% CM were performed with PBS (pH 7.4) and evaluated by ELISA assay using purified guinea pig IgG by affinity chromatography.Results: The average particle size of 1%, 2% and 3% of CM were determined by optical microscopic method and particle size was found to be 30μm, 31μm, and 35μm respectively. Percentage of TT adsorbed in 1%, 2% and 3% CM were found to be 71%, 80% and 76% respectively by Limes flocculation method. In vitro studies showed that different batches (1%, 2% and 3%) of CM showed cumulative percentage release of TT 74.09%, 89.31%, and 80.23% respectively for 50 days. Among three batches of microspheres, 2% of chitosan microspheres showed better consistent and sustained release of TT for 50 days.Conclusions: This study suggested that 2% of chitosan microspheres could be useful for sustained release of tetanus toxoid to maintain the antibody titre for prolonged period.Keywords: Tetanus toxoid, Chitosan microspheres, Single shot vaccine
Methyl Eugenol (Parapheromone) Trapping System on Diversity of Fruit Flies and Influence of Weather Parameters on Trap Catches in Mango and Guava Cropping Systems
Studies on species diversity and influence of weather parameters on methyl eugenol (parapheromone) trap catches were carried out in mango and guava orchards at Coimbatore and Dindigul Districts of Tamil Nadu from Standard Meteorological Week (SMW) 16th to SMW 25th. Species diversity indices were calculated, and the methyl eugenol trap catches were correlated with the weather parameters. The results revealed that four fruit fly species viz., Oriental fruit fly, Bactrocera dorsalis (Hendel), Guava fruit fly, B. correcta (Bezii), B. caryeae (Kapoor), and Peach fruit fly, B. zonata (Saunders), were attracted to the parapheromone methyl eugenol traps. Among them the population of B. dorsalis was higher in both mango and guava orchards of Coimbatore and Dindigul Districts. The highest species diversity indices for fruit flies viz., Shannon H’ (0.936) and Simpsons D’ (0.593), evenness (0.468), and richness (0.482) were observed in guava orchard located in Coimbatore District, and the minimum diversity indices Shannon H’ (0.254), Simpsons D’ (0.921), evenness (0.160), and richness (0.291), were observed in mango orchard located in Dindigul District. The maximum number of fruit flies were trapped in 19th SMW in mango orchards in both Districts 134 and 145 flies/three traps, respectively. In Coimbatore District’s guava orchard and Dindigul District's mango orchard, trap catches revealed a significant positive correlation with rainfall. The subsequent weather parameters like max. temperature, min. temperature, wind speed, and relative humidity, were either positively or negatively correlated with trap catches in mango and guava orchards. In multiple regression analysis, the maximum predictability was seen in mango orchard (75.54%) located in Coimbatore District and the minimum (66.68%) in mango orchard located in Dindigul District