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| Registros recuperados: 978 | |
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| Jones,Phillip B.C.. |
| During the fall of 1998, three research groups announced that they had devised methods for obtaining human embryonic stem cells. Human stem cells are characterized by the ability to form many cell types, and the scientific community anticipates that the cells should be useful for the treatment of a wide variety of diseases. The dilemma is that human stem cell methodology can require, at least to some extent, research with human fetal tissue or research involving human embryos. Those opposed to federal funding of the former are concerned that the studies would support the "legitimacy" of abortion, while the latter is seen as prohibited under current law. The National Bioethics Advisory Committee has suggested that the federal government should fund both... |
| Tipo: Journal article |
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| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582000000100003 |
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| Masani,Mat Yunus Abdul; Parveez,Ghulam Kadir Ahmad. |
| The main target of Malaysian Palm Oil Board (MPOB) genetic engineering programme is to produce high oleate transgenic palms. The availability of effective transformation vector is one of the pre-requisites for genetic manipulation of oil palm through recombinant DNA technology. Here, we describe the construction of a series of transformation vectors that have a maize ubiquitin promoter (UbiPro)-driven bar gene for selection of transformants on herbicide (Basta or Bialaphos), and mesocarp-specific promoter (MSP1) for expression of the transgenes [antisense palmitoyl-ACP-thioesterase (PAT) and sense β-ketoacyl-ACP-synthase II (KASII) and sense Δ9-stearoyl-ACP-desaturase (SAD)] potentially responsible for high oleate content in oil palm... |
| Tipo: Journal article |
Palavras-chave: Oleate; Transformation vectors; Transgenic oil palm. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000300003 |
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| Suliman Al-Badah,Abdulhakim; S.S. Ibrahim,Abdelnasser; Al-Salamah,Ali A; Ibrahim,Shebl Salah S. |
| Background Enterococcus faecalis is considered to be one of most prevalent species in the oral cavity, particularly in endodontic infections. The aim of the present study was to investigate the prevalence of E. faecalis in dental root canals, clonal diversity by restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD-PCR) analysis, and the antibiotic susceptibility of E. faecalis isolates. Results Among the bacterial strains isolated from dental root canal specimens (n = 82), E. faecalis was determined to have the highest prevalence followed by Streptococcus viridians, Leuconostoc mesenteroides, Staphylococcus aureus, Streptococcus mitis, and Pediococcus pentosaceus. Cluster analysis of RAPD-PCR and RFLP patterns of the... |
| Tipo: Journal article |
Palavras-chave: Antimicrobial susceptibility; Endodontic infection; Enterococcus faecalis; Genotype; RAPD; RFLP. |
| Ano: 2015 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582015000300006 |
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| Gentina,Juan Carlos; Acevedo,Fernando. |
| Background: Bioleaching of minerals is a process that allows the treatment of insoluble sulphides and insoluble oxides via hydrometallurgy, as opposed to the more traditional technology of pyrometallurgy. Bioleaching presents several technological, environmental and economic advantages as compared with pyrometallurgy, as well as some limitations. Results: In this work a general panorama of copper mining and biomining, the influence of the most relevant operating variables and their present and future situation in Chile are presented and discussed. Conclusions: Today, Chile plays an important role in the development and commercial application of bioleaching to copper ores. This background information allows predicting a brilliant future for this technology... |
| Tipo: Journal article |
Palavras-chave: Dumps; Heap leaching; Hydrometallurgy; Leaching microorganisms; Pyrometallurgy. |
| Ano: 2013 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582013000300016 |
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| Çevrml,Bekir Stk; Karipta,Ergin; Yaar,Ahmet; Ytolu,Mustafa. |
| Influences of phenol, ?-naphtol and ?-naphtol, which are toxic chemicals, on citric acid biosynthesis and biomass in the artificial culture setting of Aspergillus niger using batch fermenter are examined in the most favorable fermentation conditions, and a model is proposed. Addition of certain concentrations of phenol, ?-naphtol and ?-naphtol to the culture increases the citric acid production. According to this model, maximum citric acid concentration is 48.3 g L-1 in a culture that does not contain any toxic chemicals, whereas the maximum concentrations obtained in cultures containing 25 mg L-1 phenol, 25 mg L-1 alpha-naphtol and 15 mg L-1 beta-naphtol are 62.5 g L-1, 78.1 g L-1 and 86.0 g L-1, respectively. Moreover, addition of toxic chemicals to the... |
| Tipo: Journal article |
Palavras-chave: A. niger; Citric acid; Fermenter; Toxic chemicals (phenols). |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000600008 |
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| Cesio,Verónica; Dutra,Carmelo; Moyna,Patrick; Heinzen,Horacio. |
| Morphological variation in type IV trichomes in Ss and Ng was studied through SEM. The differences can be related to chemical differences in the excreted sugar esters. Ng trichomes exude two fractions, one of glucose tri-esters and the other one of sucrose tetra-esters, in a 3:7 ratio. The main acid found forming these esthers, is 3-methylvalerianic acid, in consonance to those secreted by other Solanaceae. Esters from Ss are novel structures, which can also be separated into three fractions, two of arabinoxylans, and the other one of arabinose, all glycosilated with β-hydroxipalmitic acid and sterified with the C12-C16 acids. All five fractions have antifungic activity at μg/cm² concentrations, both against common and mycotoxigenic... |
| Tipo: Journal article |
Palavras-chave: Antifungic activity; Interespecies variability; Mycotoxins; Sugar esters. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000300021 |
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| Lin,Ling; Kan,Xianzhao; Yan,Hao; Wang,Danni. |
| The gram-positive spore-forming bacteria, Bacillus thuringiensis (Bt) strains produced novel cellulases which could liberate glucose from soluble cellulose, carboxymethyl cellulose (CMC), and insoluble crystalline cellulose. The maximal cellulase activities were obtained after 60 hrs incubation at 28ºC in a LB broth medium with 1% CMC. Maximum CMCase activities were got at 40ºC and pH 4.0, respectively, and more than 50% of its maximal activity was retained at 40-60ºC for 1 hr, while approximately 40% of its maximal activity was also retained after incubating at 70ºC for 1 hr. Most metal ions and reagents such as Ca2+, Mg2+, Cd2+, Pb2+, Zn2+, Cu2+, EDTA, and SDS inhibited the enzyme activities, but K+ and Mn2+ activated the activities. The enzymes from... |
| Tipo: Journal article |
Palavras-chave: Bacillus thuringiensis; Cellulase; Cellulose-degrading; Characterization. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582012000300002 |
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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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| Flachowsky,Henryk; Riedel,Marko; Reim,Stefanie; Hanke,Magda-Viola. |
| The generation of transgenic apple plants relies on the molecular analysis of transgene integration and expression based on polymerase chain reaction (PCR) analysis, blotting techniques and enzymatic assays on vitro leaves of putative transgenic regenerates. In order to assess the uniformity and the stability of transfer DNA (T-DNA) integration and gene expression, we studied 26 transgenic apple lines carrying the attacin E gene from Hyalophora cecropia, the β-glucuronidase gene, and the nptII gene. Plants were evaluated using standard molecular techniques, such as PCR, Southern blot, reverse transcription PCR (RT-PCR) and Enzyme Linked Immunosorbent Assay (ELISA), and propagated in vitro on non-selective antibiotic-free media for four years to... |
| Tipo: Journal article |
Palavras-chave: Agrobacterium tumefaciens; Apple; Chimeric tissue; Gene silencing; Malus domestica; T-DNA leakage. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000100003 |
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| Bustamante,José O. |
| Coconut is a major crop of many poor nations. The present paper shows with inexpensive fluorescence microscopy of the enhanced green fluorescent protein (EGFP), that coconut water has the capability of synthesizing proteins from recombinant DNA vectors. After only 4 hrs of 100 pM application of the EGFP plasmid (pEGFP), a strong fluorescent signal was detected with an off-the-shelf, low-tech CCD webcam. Since natural coconut water is sterile, this heat-stable delivery system may be a good option for the dissemination of food supplements and pharmaceuticals in poor nations. As expensive substances could be expressed in coconut water, through bioreactor technology or micropropagation, the concepts presented here may prove invaluable to the economic and... |
| Tipo: Journal article |
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| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000100002 |
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| Bazzini,Ariel A; Mongelli,Vanesa C; Hopp,H. Esteban; del Vas,Mariana; Asurmendi,Sebastián. |
| Gene silencing, also called RNA interference (RNAi) is a specific mechanism of RNA degradation involved in gene regulation, development and defense in eukaryotic organisms. It became an important subject in the teaching programs of molecular biology, genetics and biotechnology courses in the last years. The aim of this work is to provide simple and inexpensive assays to understand and teach gene silencing using plants as model systems. The use of transient and permanent transgenic plants for expressing reporter genes, like those derived from jellyfish green fluorescent protein (gfp) encoding gene, provides a nice, colorful and conclusive image of gene silencing. Three experimental approaches to evidence RNA silencing are depicted. In the first approach... |
| Tipo: Journal article |
Palavras-chave: Gene silencing; GFP; HC-Pro; PDS; Protocols; PTGS; Teaching; Transgenic; Transient expression; TRV; VIGS. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000200002 |
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| Narayanan,Niju; Roychoudhury,Pradip K.; Srivastava,Aradhana. |
| Lactic acid has been first introduced to us as early as 1780 as a sour component of milk. Ever since we have found its applications in food, pharmaceutical, cosmetic industries etc. Now there are emerging uses as a potential feedstock for the biodegradable polymer industry. The microorganisms being used for lactic acid fermentation, the raw materials reported, the various novel fermentation processes and its processing methods have been reviewed. The properties and applications of lactic acid, its derivatives and polymer have been discussed. The various routes to polymerization and the companies presently involved in lactic acid production have been covered |
| Tipo: Journal article |
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| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200008 |
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| We have constructed a fusion protein between mSlo (a recombinant, high conductance, calcium-activated potassium channel or maxi-K), and GFP (green fluorescent protein). This construct represents a tag to not only monitor channel expression, but to locate the protein in living cells. The GFP was fused in frame to the carboxy-terminus of the mSlo core protein (mSlo-GFP fusion protein). Expression of this fusion protein in COS-7 cells resulted in robust fluorescence localized near the cell membrane. Fluorescing cells that were patch clamped exhibited whole cell currents with a direction consistent with potassium currents. Conversely, non-fluorescing cells showed no significant whole cell currents. Excised inside out patches revealed single channel currents... |
| Tipo: Journal article |
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| Ano: 1999 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34581999000300003 |
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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: 978 | |
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