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991.

Pfaffia glomerata has potential pharmacological and medicinal properties due to the production of a secondary metabolite known as the phytoecdysteroid 20-hydroxyecdysone (20E). There have been increasing efforts for massive in vitro propagation of Pfaffia plants due to high extractivism and overharvesting of this species. Research on the species has shown that photoautotrophic cultivation can improve the production of 20E. In addition, other abiotic factors such as the formulations of culture media can influence the morphophysiological behavior of the plants in vitro. Therefore, the objective of this study was to analyze the morphological and physiological performances of P. glomerata plants in different formulations of culture media, under photoautotrophic and photomixotrophic propagation conditions. Six medium formulations, the Driver and Kuniyuki medium (DKW), Correia et al. medium (JADS), Murashige and Skoog medium (MS), Quoirin and Lepoivre medium (QL), Rugini medium (OM), and Woody Plant medium (WPM), all supplemented with DKW vitamins, 100 mg L−1 myo-inositol, 6.5 g L−1 agar, and with or without 3% (w/v) sucrose, were evaluated. Cultures were maintained at 25 ± 2°C, with a 16 h-photoperiod under 60 μmol m−2 s−1 of irradiance under a fluorescent lamp for 50 d. Results showed that the presence or absence of sucrose, and the different nutritional formulations influenced growth, photosynthetic pigment content, endogenous levels of sugars, leaf morphology, levels of 20E, and transport of water and minerals in P. glomerata. Notably, OM, DKW, QL, and WPM media promoted higher production of 20E under photomixotrophic growth conditions.

  相似文献   
992.
BackgroundHigh-grade gliomas (HGGs) are a heterogeneous disease group, with variable prognosis, inevitably causing deterioration of the quality of life. The estimated 2-year overall survival is 20%, despite the best trimodality treatment consisting of surgery, chemotherapy, and radiotherapy.AimTo evaluate long-term survival outcomes and factors influencing the survival of patients with high-grade gliomas treated with radiotherapy.Materials and methodsData from 47 patients diagnosed with high-grade gliomas between 2009 and 2014 and treated with three-dimensional radiotherapy (3DRT) or intensity-modulated radiotherapy (IMRT) were analyzed retrospectively.ResultsMedian survival was 16.6 months; 29 patients (62%) died before the time of analysis. IMRT was employed in 68% of cases. The mean duration of radiotherapy was 56 days, and the mean delay to the start of radiotherapy was 61.7 days (range, 27–123 days). There were no statistically significant effects of duration of radiotherapy or delay to the start of radiotherapy on patient outcomes.ConclusionsAge, total amount of gross resection, histological type, and use of adjuvant temozolomide influenced survival rate (p < 0.05). The estimated overall survival was 18 months (Kaplan–Meier estimator). Our results corroborated those reported in the literature.  相似文献   
993.
994.
Gomes, S. R., Britto da Silva, F., Mendes, I. L. V., Thomé, J. W. & Bonatto, S. L. (2009). Molecular phylogeny of the South American land slug Phyllocaulis (Mollusca, Soleolifera, Veronicellidae). —Zoologica Scripta, 39, 177–186. Our main objectives were investigate the phylogenetic relationships between the species of the land slug Phyllocaulis and the monophyly of the genus based on mitochondrial (16S and COI) and nuclear (ITS2) DNA sequences from multiple individuals from each species. Evolutionary trees were constructed using Bayesian inference, maximum likelihood, maximum parsimony and neighbor‐joining methods. All species accepted in the current taxonomy based on penial characteristics and radular measurements were reciprocally monophyletic. Five species out of six formed a clade with the following highly supported relationship: Phyllocaulis gayi, Phyllocaulis soleiformis, Phyllocaulis renschi, Phyllocaulis variegatus, Phyllocaulis boraceiensis. The position of Vaginulus taunaisii changed according to the analysis, appearing as sister‐group of Phyllocaulis or as sister‐group of Phyllocaulis tuberculosus. Divergence times estimated from the 16S tree indicated that the extant species of Phyllocaulis shared a common ancestor around 1.3 Ma and that most species originated between 0.8 and 0.6 Ma.  相似文献   
995.
Crypthecodinium cohnii with emphasis on DHA production: a review   总被引:3,自引:0,他引:3  
Docosahexaenoic acid (DHA) is a polyunsaturated fatty acid (PUFA) that belongs to the ω-3 group. In recent years, DHA has attracted much attention because of its recognized beneficial effect on human health. At present, fish oil is the major source of DHA, but it may be produced by microorganisms with additional benefits. Marine microorganisms may contain large amounts of DHA and are considered a potential source of this important fatty acid. Some of these organisms can be grown heterotrophically on organic substrates without light, offering the possibility of greatly increasing microalgal cell concentration under controlled and monitored conditions, resulting in a very high quality product. Among the heterotrophic marine dinoflagellates, Crypthecodinium cohnii has been identified as a prolific producer of DHA. The organism is extraordinary in that it produces no other PUFAs than DHA in its cell lipid in any significant amount, which makes the DHA purification process very attractive, particularly for pharmaceutical and nutraceutical applications. This paper reviews recent advances in the biotechnological production of DHA by C. cohnii.  相似文献   
996.
997.
This study evaluated the partitioning of ovomucoid from egg white, in aqueous two-phase systems (ATPS) composed of PEG 1500 and inorganic salt (lithium sulfate, sodium sulfate, magnesium sulfate, sodium carbonate or sodium citrate) at 25 °C. The results showed a great effect of the electrolyte nature on the partition coefficient. The partition coefficient value ranges from 0.02 to 6.0. The highest partition coefficients were obtained from systems composed of sodium carbonate and the lowest in systems composed of magnesium sulfate. In the system containing magnesium sulfate, a recovery percentage greater than 90% was obtained.  相似文献   
998.
Different immobilized preparations of three different lipases – those from Aspergillus niger (ANL), Candida rugose (CRL) and Candida antarctica B (CAL-B) – have been used in the regioselective monohydrolysis of different peracetylated-β-galactopyranosides. Three very different immobilization strategies – covalent attachment, anionic exchange and interfacial activation on a hydrophobic support – were employed for each lipase. The role of the immobilization strategy on the hydrolytic activities, specificities and regioselectivities of the lipases were investigated. Moreover, the effect the biocatalysts performance of the presence of different moieties in the anomeric position of the substrate was analyzed. The PEI-ANL immobilized preparation was six times more active than the CNBr-ANL in the hydrolysis of 1-thioisopropyl-2,3,4,6-tetra-O-acetyl-β-d-galactopyranoside whereas the CNBr-ANL showed 2 times more activity than the PEI-ANL in the hydrolysis of galactal. Using CRL, the octyl-CRL was completely specific and regioselective in the hydrolysis of galactal, producing the C-6 monohydroxylated product in 99% yield. The PEI-CRL showed low specificity and poor regioselectivity, hydrolyzing in C-6 but also in C-3 positions whereas the PEI-CRL preparation showed good specificity although low regioselectivity, hydrolyzing in C-6, C-4 and C-3 positions.  相似文献   
999.
1000.
The discovery of microRNAs (miRNAs), almost 10 years ago, changed dramatically our perspective on eukaryotic gene expression regulation. However, the broad and important functions of these regulators are only now becoming apparent. The expansion of our catalogue of miRNA genes and the identification of the genes they regulate owe much to the development of sophisticated computational tools that have helped either to focus or interpret experimental assays. In this article, we review the methods for miRNA gene finding and target identification that have been proposed in the last few years. We identify some problems that current approaches have not yet been able to overcome and we offer some perspectives on the next generation of computational methods.  相似文献   
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