48 research outputs found

    PHARMACOGNOSTIC AND HPTLC BASED COMPARATIVE STUDY ON LEAVES OF MERREMIA EMARGINATA BURM. F. AND CENTELLA ASIATICA (L.) URBAN

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    Objective: In this study, an attempt was made to generate information based on botanical, physicochemical and HPTLC data needed for proper identification and authentication of M. emarginata and C. asiatica belonging to two different families. Methods: Botanical study comprises of macroscopy, microscopy and powder microscopy of leaves of both crude drugs. The physicochemical parameters such as water-soluble extractive, alcohol soluble extractive and loss on drying at 105℃, total ash, acid insoluble ash, and volatile oil were determined according to standard methods. HPTLC studies of chloroform extracts of leaves of both drugs were conducted at 254 nm, 366 nm and 575 nm after derivatisation using vanillin-sulphuric acid and the results were documented. Results: The present study reveals that microscopy and most of the physicochemical parameters of both the plant materials are different. Anatomy of the leaves showed two main characteristic differences. First plenty of trichome with trichome base and calcium oxalate crystal is common in M. emarginata, which is not observed in C. asiatica. Both plants have different venation patterns and leaf constants. The total ash content and the solubility in alcohol and water for leaves of C. asiatica are higher than that of M. emarginata. The HPTLC fingerprinting pattern obtained for both drugs are different. Conclusion: All the results obtained from this study help in determining differences and similarities of leaves of M. emarginata and C. asiatica and thereby preventing adulteration and substitution and emphasizing the importance of standardization

    Transient Expression of Hemagglutinin Antigen from Low Pathogenic Avian Influenza A (H7N7) in Nicotiana benthamiana

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    The influenza A virus is of global concern for the poultry industry, especially the H5 and H7 subtypes as they have the potential to become highly pathogenic for poultry. In this study, the hemagglutinin (HA) of a low pathogenic avian influenza virus of the H7N7 subtype isolated from a Swedish mallard Anas platyrhynchos was sequenced, characterized and transiently expressed in Nicotiana benthamiana. Recently, plant expression systems have gained interest as an alternative for the production of vaccine antigens. To examine the possibility of expressing the HA protein in N. benthamiana, a cDNA fragment encoding the HA gene was synthesized de novo, modified with a Kozak sequence, a PR1a signal peptide, a C-terminal hexahistidine (6×His) tag, and an endoplasmic retention signal (SEKDEL). The construct was cloned into a Cowpea mosaic virus (CPMV)-based vector (pEAQ-HT) and the resulting pEAQ-HT-HA plasmid, along with a vector (pJL3:p19) containing the viral gene-silencing suppressor p19 from Tomato bushy stunt virus, was agro-infiltrated into N. benthamiana. The highest gene expression of recombinant plant-produced, uncleaved HA (rHA0), as measured by quantitative real-time PCR was detected at 6 days post infiltration (dpi). Guided by the gene expression profile, rHA0 protein was extracted at 6 dpi and subsequently purified utilizing the 6×His tag and immobilized metal ion adsorption chromatography. The yield was 0.2 g purified protein per kg fresh weight of leaves. Further molecular characterizations showed that the purified rHA0 protein was N-glycosylated and its identity confirmed by liquid chromatography-tandem mass spectrometry. In addition, the purified rHA0 exhibited hemagglutination and hemagglutination inhibition activity indicating that the rHA0 shares structural and functional properties with native HA protein of H7 influenza virus. Our results indicate that rHA0 maintained its native antigenicity and specificity, providing a good source of vaccine antigen to induce immune response in poultry species

    Rewiring carotenoid biosynthesis in plants using a viral vector

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    [EN] Plants can be engineered to sustainably produce compounds of nutritional, industrial or pharmaceutical relevance. This is, however, a challenging task as extensive regulation of biosynthetic pathways often hampers major metabolic changes. Here we describe the use of a viral vector derived from Tobacco etch virus to express a whole heterologous metabolic pathway that produces the health-promoting carotenoid lycopene in tobacco tissues. The pathway consisted in three enzymes from the soil bacteria Pantoea ananatis. Lycopene is present at undetectable levels in chloroplasts of non-infected leaves. In tissues infected with the viral vector, however, lycopene comprised approximately 10% of the total carotenoid content. Our research further showed that plant viruses that express P. ananatis phytoene synthase (crtB), one of the three enzymes of the heterologous pathway, trigger an accumulation of endogenous carotenoids, which together with a reduction in chlorophylls eventually result in a bright yellow pigmentation of infected tissues in various host-virus combinations. So, besides illustrating the potential of viral vectors for engineering complex metabolic pathways, we also show a yellow carotenoid-based reporter that can be used to visually track infection dynamics of plant viruses either alone or in combination with other visual markers.We thank Veronica Aragones and M. Rosa Rodriguez-Goberna for excellent technical assistance. This research was supported by Spanish Ministerio de Economia y Competitividad (MINECO) grants BIO2014-54269-R to J.-A.D., and BIO2014-59092-P and BIO2015-71703-REDT to M. R.-C. Financial support from the Generalitat Valenciana (PROMETEOII/2014/021), the Programa Iberoamericano de Ciencia y Tecnologia para el Desarrollo (Ibercarot 112RT0445), and the Generalitat de Catalunya (2014SGR-1434) is also acknowledged. E.M. is the recipient of a pre-doctoral fellowship (AP2012-3751) from the Spanish Ministerio de Educacion, Cultura y Deporte. B.L. is supported by a postdoctoral fellowship (FPDI-2013-018882) from MINECO.Majer, E.; Llorente, B.; Rodríguez-Concepción, M.; Daros Arnau, JA. (2017). Rewiring carotenoid biosynthesis in plants using a viral vector. Scientific Reports. 7. https://doi.org/10.1038/srep41645S7O’Connor, S. E. Engineering of secondary metabolism. Annu. Rev. Genet. 49, 71–94 (2015).Sainsbury, F. & Lomonossoff, G. P. Transient expressions of synthetic biology in plants. Curr. Opin. Plant Biol. 19, 1–7 (2014).Gleba, Y. Y., Tusé, D. & Giritch, A. Plant viral vectors for delivery by Agrobacterium. Curr. Top. Microbiol. 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    Experimental Studies on a 1/12 Scale Model of Prithvi Missile

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    Wind Tunnel Tests were carried out to determine the Longitudinal. static stability and roll control characteristics of a 1/12 scale 'PRITHVI' missile configuration with cruciform trapezoidal wings and aft tail fin controls . The tests were conducted ih the 1 .2m Trisonic wind tunnel at Mach numbers from 0 .4 to 1 .5 through an angle of attack range of -10° to 20° . Model roll orientation was varied from -45° to 45 ° . The results indicated good longitudinal stability characteristics throughout the test Mach number range

    Wind Tunnel Force Measurements on 1/12 Scale Model of PRITHVI missile Configuration - II : Final Report

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    This report presents the aerodynamic data generated on a 1/12 scale model of PRITHVI missile configuration - II through tests in the NAL 1.2m wind tunnel. The tests were carried out to obtain aerodynamic data to determine the control effectiveness characteristics of the tail fin Controlled missile model. The presentation of test results include the following : (i) basic tests (without CDS) and roll effectiveness tests at M=0.4 to 1.2 (ii) Pitch and yaw effectiveness tests in the Mach number range 1.5 to 3.5 (iii) Effect of protrusions on the basic configuration. The test Reynolds number based on the body diameter varied from 1.1 million to 2.8 million. Complete test results are given in the form of tables with few typical plots

    Estimation of error in measurement of force and moment coefficients of wind tunnel models

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    It 1s general practice to give the accuracy of measurement of moment and force coefficients from wind tunnel, repeatability tests and the level of uncertainties estimated from various instruments used. However, since the repeatability tests could't be carried out, a method based on the principle of propagation of errors has been used to get the accuracy in force and moment coefficients derived from errors in measurements of all independent parameters. A computer code has been written to get the level of uncertainties and percentage of ,error of various coefficients measured. ,The.listing of the code is given along with the sample output in th form of tables and graphs

    Some studies on induced rolling moment of a missile type configuration 13; 13;

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    Force tests were carried out on a typical missile configuration, featuring a slender body cruciform canard and cruciform tail, in a 1.2-m wind tunnel at subsonic, transonic, and supersonic speeds at various incidence and control deflections. Some discussions on the induced rolling moment experienced by this configuration during maneuvering attitudes are presented. It was observed that the induced rolling moment was primarily due to the interaction of asymmetric flow field induced by the canard deflections on the tail. This induced rolling moment was negligibly small when the tail fins were removed. Also, the variation of the induced rolling moment with incidence was approximately sinusoidal for most of the canard deflections. This paper also includes some discussions on a current method adopted for eliminating such undesirable induced rolling moments by allowing the tail fin to roll freely

    Attitude and practice regarding Hepatitis B vaccination among medical students in a teaching medical institution in Puducherry

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    The incidence of liver diseases associated with hepatitis B virus remains a global public health problem. Medical personnel are the first contact between such patients and health care and medical students are indeed at risk of the same. Present cross-sectional study was undertaken among second year medical undergraduates of MGMC and RI, Puducherry during August 2012, to assess the attitude and practices of medical students towards hepatitis B vaccination (HBV) and find out the vaccination coverage among them. After brief introduction about rationale of the study a pre-tested, self-administered, anonymous questionnaires was distributed. Information regarding background characteristics of participants, Hep-B vaccination coverage and reasons for poor acceptance/compliance were collected. The questionnaires were distributed on a single day in order to avoid sharing of information. Data was analyzed using statistical software using SPSSversion 16.0. Out of total 150 questionnaires circulated, 120 (response rate 80%) were returned (Male 53.3%, Female 46.7%). Among them 21 (17.5%) students had already received three doses of Hep-B vaccination. 22 (18.3%) students didn't receive any dose. Reasons for poor coverage and/or non-compliance of Hep-B vaccination among medical students include forgot to complete the course (43.4%), not a mandatory process in the institution (26.3%), not compulsory for every individual (18.2%), fear of injections (4%) and expensive (5.1%). Coverage of Hep-B vaccination was poor among medical undergraduates in the present study. Concerted efforts should be made to motivate medical students and their family members towards Hep-B vaccination with support from medical college and medical council of India. The admission day can be utilized as an avenue for this initiative
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