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| Registros recuperados: 11.818 | |
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| Rupachandra Singh,Laishram; Ranjana Devi,Yengkokpam; Kunjeshwori Devi,Sanjenbam. |
| Proteinases have the potential to effect partial solubilization of the proteinaceous gum sericin involved in binding the silk strands together in cocoon, an essential step in the silk cocoon cooking and reeling. Therefore, pineapple extract rich in cysteine proteinases was enzymologically characterized for its potential application in oak tasar (Antheraea proylei J.) silk cocoon cooking and reeling. Optimum sodium carbonate concentration (9.8 mM) and optimum temperature (60ºC) for the proteinase activity were determined. Though relatively thermostable, an enhanced activity loss was observed when the extract was incubated in the temperature range 70-90ºC with sodium carbonate. Bulk of the activity (80-83%) remained after 1 hr of time-dependent inactivation... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300005 |
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| Montealegre,Jaime R.; Reyes,Rodrigo; Pérez,Luz María; Herrera,Rodrigo; Silva,Polyana; Besoain,Ximena. |
| Bacteria from the rhizoplane and surrounding soil of healthy and Rhizoctonia solani diseased tomato plants, cropped in greenhouse of the V Region of Chile, were collected. The best bacterial strains, based on their ability to control development of three R. solani isolates (identified as belonging to the anastomosis groups AG-2-1, AG‑4), were identified as B. subtilis (one isolate) and B. lentimorbus (two different isolates). All bacterial isolates resulted effective for the in vitro control of growth of all R. solani isolates, where the control mechanisms used by the bacteria do not involve the secretion of fungal cell wall hydrolytic enzymes. R. solani AG-2-1 was more sensitive than R. solani AG-4. On the other hand, all bacteria grew well in... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000200006 |
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| Ojalvo,Ariana G.; Seralena,Alina; Vázquez,Raysa; Montequín,José F; Vispo,Nelson S.; Silva,Ricardo; Aldama,Alfredo; Puchades,Yaquelin; Sorell,Luis T.; Lopez-Saura,Pedro; Alfonso,María A.; Simón,Rafael; Alí,Alfonso; Seuc,Armando; Herrera,Luis. |
| Abstract <A HREF="../../../../fbpe/img/ejb/v6n3/a02/bip/bip.html">Reprint (BIP)</A> <A HREF="../../../../fbpe/img/ejb/v6n3/a02/reprint.html">Reprint (PDF)</A> Abstract <A HREF="#article">Article </A> <A HREF="#references">References </A> Vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, has been shown to promote therapeutic angiogenesis in animal models of critical limb ischemia. Ischemic skeletal muscle is advantageous for taking up and expressing foreign genes transferred as naked plasmid DNA. Accordingly, we investigated the hypothesis that intramuscular administration of naked plasmid DNA encoding the 121-amino acid isoform of VEGF could augment collateral development and... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300006 |
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| Vara Prasad,Majeti Narasimha; de Oliveira Freitas,Helena Maria. |
| The importance of biodiversity (below and above ground) is increasingly considered for the cleanup of the metal contaminated and polluted ecosystems. This subject is emerging as a cutting edge area of research gaining commercial significance in the contemporary field of environmental biotechnology. Several microbes, including mycorrhizal and non-mycorrhizal fungi, agricultural and vegetable crops, ornamentals, and wild metal hyperaccumulating plants are being tested both in lab and field conditions for decontaminating the metalliferous substrates in the environment. As on todate about 400 plants that hyperaccumulate metals are reported. The families dominating these members are Asteraceae, Brassicaceae, Caryophyllaceae, Cyperaceae, Cunouniaceae, Fabaceae,... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300012 |
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| Li,Mingshan; Leung,David W.M.. |
| Root induction using Agrobacterium rhizogenes was conducted in hypocotyl explants, intact seedlings, de-rooted seedling cuttings and adventitious shoots of radiata pine (Pinus radiata D. Don). Use of two A. rhizogenes strains (A4T and LB9402), with or without application of IBA, can trigger root formation in different explants. Strain LBA9402 was more effective than A4T in increasing rooting percentage and root number. Addition of 4.4 uMIBA to the medium further enhanced rooting from the cultured hypocotyl segments inoculated with the two A. rhizogenes strains. Strain LBA9402+IBA induced in about 75% of the cultured hypocotyl segments to form roots. In contrast the controls failed to initiate roots on intact seedlings or cultured segments in presence or... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300010 |
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| Bonny,Sylvie. |
| A strong movement of opposition to GMOs developed in the late 1990s in many countries, especially in Europe, although these technologies were presented from the outset as highly promising and their advantages were often highlighted. How can this rejection be explained? The aim of this paper is to answer that question through the case of France, which is fairly representative in this respect of various European countries, even if the opposition movement is here particularly strong. One examines various factors, actors and processes that have led to such strong opposition to GMOs that at this stage their development in Europe has almost totally been halted. In the first part of the article we recall the results of several recent surveys, showing the level of... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000100008 |
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| Marshall,Sergio H.; Arenas,Gloria. |
| A large group of low molecular weight natural compounds that exhibit antimicrobial activity has been isolated from animals and plants during the past two decades. Among them, cationic peptides are the most widespread. Interestingly, the variety and diversity of these peptides seem to be much wider than suspected. In fact, novel classes of peptides with varying chemical propertiescontinue to be isolated from different vertebrate and invertebrate species, as well as from bacteria. To the early characterized peptides, mostly cationic in nature, anionic peptides, aromatic dipeptides, processed forms of oxygen-binding proteins and processed forms of natural structural and functional proteins can now be added, just to name a few. In spite of the astonishing... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300011 |
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| Morales G.,Esteban. |
| In the coming years the worldwide energetic resources based on hydrocarbons will diminish, and methane hydrates can become an alternative source, given its huge deposits. Chile does not have great amounts of energetic resources; however, during the cruise C-2901 on board the R/V CONRAD in 1998, seismic profiles that took place in the Chilean continental margin between 35º and 45ºS show the presence of methane hydrates through BSR analysis. The following parameters for the hydrate layer can be assumed: Thickness = 100 m, Longitude E-W = 20 km, Latitude N-S = 1000 km, hydrate concentration in the sediments = 10%, and 160 m³ of gas per m³ of hydrate. With these figures, the volume of estimated gas is 3.2 x 10(13) m³. |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000200002 |
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| Mohd. Raih,Mohd. Firdaus; Sailan,Ahmad Tarmidi; Zamrod,Zulkeflie; Embi,Mohd. Noor; Mohamed,Rahmah. |
| Cytochrome c oxidase, the terminal enzyme of the respiratory chains of mitochondria and aerobic bacteria, catalyzes electron transfer from cytochrome c to molecular oxygen. The enzyme belongs to the haem-copper-containing oxidases superfamily. A recombinant plasmid carrying a 2.0 kb insert from a Burkholderia pseudomallei genomic library was subjected to automated DNA sequencing utilizing a primer walking strategy. Analysis of the 2002 bp insert revealed a 1536 bp open reading frame predicted to encode a putative cytochrome c oxidase. Further analysis using sequence alignments and tertiary structure analysis tools demonstrated that the hypothetical B. pseudomallei cytochrome c oxidase is similar to cytochrome c oxidases from other organisms such as Thermus... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000100005 |
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| González,Ramón; Gentina,Juan C.; Acevedo,Fernando. |
| The large-scale biooxidation of gold concentrates is usually carried on in continuous stirred tank reactors (CSTR). Attaining homogeneous slurries is a difficult task, as solids tend to stratify in the tank. The objective of this work was to determine the optimal conditions of agitation in a CSTR so to obtain the best solids suspension. The experiments were performed in a 5 litre glass tank operated with 3 litres of 6% w/v slurry. The impellers (pitched blade turbine or marine propeller) were placed at heights of 6.7 to 13.4 cm from the bottom and operated at 370 to 1040 rpm, with specific aeration rates of 0.3 to 3.7 vvm. A statistical experimental design was used which allowed the derivation of a model representing response surfaces of the exit and mean... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300008 |
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| Tzanov,Tzanko; Andreaus,Jürgen; Guebitz,Georg; Cavaco-Paulo,Artur. |
| Enzymes are the catalysts of all reactions in living systems. These reactions are catalysed in the active sites of globular proteins. The proteins are composed by amino acids with a variety of side chains ranging from non-polar aliphatic and aromatic to acidic, basic and neutral polar. This fact allows to a globular 3D protein to create in the active site all ranges of microenvironments for catalysis. Major advances in microbial technology and genetics allow recently the broad range of enzymatic applications in the industry. Enzymatic processes have been increasingly incorporated in textiles over the last years. Cotton, wool, flax or starches are natural materials used in textiles that can be processed with enzymes. Enzymes have been used for desizing,... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300013 |
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| Jirathitikal,Vichai; Metadilogkul,Orapun; Bourinbaiar,Aldar S.. |
| V-1 Immunitor (V1) is an oral AIDS vaccine currently being used as a therapeutic modality by HIV-positive patients. Upon interim analysis of phase I safety trial it has been discovered that patients who had elevated liver enzymes aspartate (AST/SGOT) and alanine (ALT/SGPT) aminotransferases have experienced the reduction of enzyme levels back to normal. Two other hepatitis markers alkaline phosphatase and bilirubin have also decreased. V1s effect may be hepatitis-specific since liver enzymes in normal patients treated with V1 have not changed and three patients who were Hepatitis B antigen positive at baseline became negative after therapy. The results suggest that V1 supplementation reduces hepatic damage caused by hepatitis viral infection. |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000100010 |
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| Da Silva,Rafael Fernandez; Menéndez-Yuffá,Andrea. |
| Different electroporation conditions were evaluated, toward the goal of transformation of Coffea arabica cv. Catimor. The tissues assayed were: embryogenic calli, leaf sections from in vitro plants, and somatic embryos in globular and torpedo stage obtained from cell suspensions. The effect of 1 or 24-hour pretreatment with an enzymatic solution (2% cellulase, 1% macerozyme) and electric field strength (375, 625, 875 V/cm) was evaluated. In all the experiments the tissues were incubated in ASP buffer (potassium aspartate) during three hours, and then one hour with plasmid DNA (pCambia3201, containing gus and bar genes) at room temperature. The electroporation was performed at a capacitance of 900 μF. The effect of the parameters evaluated was... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000100006 |
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| Champagne,Claude P; Gaudreau,Hélène; Conway,John. |
| Three brewers and three bakers yeast extracts (YE) were obtained from five commercial suppliers. They were added to microbiological media and their growth-promoting properties were examined using four lactic cultures (Lactobacillus casei EQ28 and EQ85, Lactobacillus acidophilus EQ57, Pediococcus acidilactici MA18/5-M). Bakers YE have a higher total nitrogen content than brewers YE, but there was not always a correlation between the nitrogen content and growth. A systematic preference for bakers YE over brewers YE was only encountered with Lb. casei EQ85, but the other lactic cultures had variable reactions to the source of YE. With Lb. casei EQ85 and Pc. acidilactici 17/5M, mixing of the two sources of YE gave progressively higher growth as a... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300004 |
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| Lakrod,Kamolnan; Chaisrisook,Chulee; Skinner,Daniel Z. |
| Albino strain KB20M1 of Monascus purpureus was genetically transformed to hygromycin B resistance with cosmid pMOcosX, using biolistic bombardment. Conidia and mycelial fragments were used as the recipient material and rupture disk strengths of 6.2 and 9.3 MPa each yielded a transformed isolate from five bombardments. Southern analysis suggested a single copy of the cosmid had integrated into each of the transformants. Both of the independent transformants formed cleistothecia but ascospore formation was greatly reduced or absent, suggesting the integration and expression of the genes carried on pMOcosX interfered with fertilization and/or ascospore formation in this homothallic fungus. |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000200007 |
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| Velankar,Harshad Ravindra; Heble,Mohan Ram. |
| This paper reports biotransformation of (L)-citronellal to (L)-citronellol using free and immobilized cells of Rhodotorula minuta. The culture preparation variables such as pH, temperature and incubation period for obtaining maximum cell growth of R. minuta were optimized. The optimized culture conditions for free and immobilized cells of R. minuta. have been compared for (L)-citronellal biotransformation. The various factors such as the optimum substrate concentration and the time of substrate addition at varying cell concentrations during the growth of yeast culture were also studied. Highest (L)-citronellol concentration of 3.5 gl-1 was obtained with free cell catalyzed biotransformation at pH 5.5, 27ºC and 150 rpm after 8 hrs using initial... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000200004 |
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| Registros recuperados: 11.818 | |
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