622 research outputs found
Trends and strategies to enhance triacylglycerols and high-value compounds in microalgae
Microalgae are important sources of triacylglycerols (TAGs) and high-value compounds such as carotenoids and long-chain polyunsaturated fatty acids (LC-PUFAs). TAGs are feedstocks for biofuels or edible oils; carotenoids are used as pigments in the food and feed industries; and LC-PUFAs are beneficial for human health, being also key to the correct development of fish in aquaculture. Current trends in microalgal biotechnology propose the combined production of biofuels with high-value compounds to turn large-scale production of microalgal biomass into an economically feasible venture. As TAGs, carotenoids and LC-PUFAs are lipophilic biomolecules, they not only share biosynthetic precursors and storage sinks, but also their regulation often depends on common environmental stimuli. In general, stressful conditions favor carotenoid and TAGs biosynthesis, whereas the highest accumulation of LC-PUFAs is usually obtained under conditions promoting growth. However, there are known exceptions to these general rules, as a few species are able to accumulate LC-PUFAs under low light, low temperature or long-term stress conditions. Thus, future research on how microalgae sense, transduce and respond to environmental stress will be crucial to understand how the biosynthesis and storage of these lipophilic molecules are regulated. The use of high-throughput methods (e.g. fluorescent activated cell sorting) will provide an excellent opportunity to isolate triple-producers, i.e. microalgae able to accumulate high levels of LC-PUFAs, carotenoids and TAGs simultaneously. Comparative transcriptomics between wild type and tripleproducers could then be used to identify key gene products involved in the regulation of these biomolecules even in microalgal species not amenable to reverse genetics. This combined approach could be a major step towards a better understanding of the microalgal metabolism under different stress conditions. Moreover, the generation of triple-producers would be essential to raise the biomass value in a biorefinery setting and contribute to meet the world's rising demand for food, feed and energy.Foundation for Science and Technology (Portugal) through research programme [CCMAR/Multi/04326/2013]doctoral research grants [SFRH/BD/105541/2014, SFRH/BD/115325/2016]Spanish Ministry of Economy and Competitiveness [AGL2016-74866-C3-02]CEIMARNord University and Nordland County Government project Bioteknologi-en framtidsrettet noeringinfo:eu-repo/semantics/publishedVersio
Use of performance indicators in the analysis of running gait impacts
[Summary]
Foot-ground impact is a critical event during the running cycle. In this work, three performance indicators were used to characterize foot-ground impact intensity: the effective preimpact kinetic energy, representative elements of the effective mass matrix, and the critical coefficient of friction. These performance indicators can be obtained from the inertial properties of the biomechanical system and its pre-impact mechanical state, avoiding the need to carry out force measurements. Ground reaction forces and kinematic data were collected from the running motion of an adult that adopted both rear-foot and fore-foot strike patterns. Different running cycles were analysed and statistical tests performed. Results showed that the three proposed indicators are able to illustrate significant differences between fore-foot and rear-foot strike impacts. They also support the hypothesis that fore-foot strike reduces impact intensity. On the other hand, a higher likelihood of slipping during the contact onset is associated with fore-foot strike pattern.Ministerio de Economía y Competitividad (MINECO). JCI-2012-1237
Tectonoelins, new norlignans from a bioactive extract of Tectona grandis
A phytochemical study on the most bioactive extract from Tectona grandis led to the isolation of two new norlignans, tectonoelin A and tectonoelin B, together with ten known compounds. The structures of the compounds were determined by a combination of 1D and 2D NMR techniques. This is the first time that this type of compound (C8–C80 linkage norlignans) has been isolated from a dicotyledon. The general bioactivities of the isolated compounds have been studied using etiolated wheat coleoptiles. The activities showed that the isolated lignans and norlignans should be part of the defence mechanisms of this plant
Neuroglial involvement in abnormal glutamate transport in the cochlear nuclei of the Igf1—/— mouse
Insulin-like growth factor 1 (IGF-1) is a powerful regulator of synaptic activity and a
deficit in this protein has a profound impact on neurotransmission, mostly on excitatory
synapses in both the developing and mature auditory system. Adult Igf1—/— mice
are animal models for the study of human syndromic deafness; they show altered
cochlear projection patterns into abnormally developed auditory neurons along with
impaired glutamate uptake in the cochlear nuclei, phenomena that probably reflect
disruptions in neuronal circuits. To determine the cellular mechanisms that might
be involved in regulating excitatory synaptic plasticity in 4-month-old Igf1—/— mice,
modifications to neuroglia, astroglial glutamate transporters (GLTs) and metabotropic
glutamate receptors (mGluRs) were assessed in the cochlear nuclei. The Igf1—/— mice
show significant decreases in IBA1 (an ionized calcium-binding adapter) and glial
fibrillary acidic protein (GFAP) mRNA expression and protein accumulation, as well
as dampened mGluR expression in conjunction with enhanced glutamate transporter
1 (GLT1) expression. By contrast, no differences were observed in the expression
of glutamate aspartate transporter (GLAST) between these Igf1—/— mice and their
heterozygous or wildtype littermates. These observations suggest that congenital IGF-1
deficiency may lead to alterations in microglia and astrocytes, an upregulation of GLT1,
and the downregulation of groups I, II and III mGluRs. Understanding the molecular,
biochemical and morphological mechanisms underlying neuronal plasticity in a mouse
model of hearing deficits will give us insight into new therapeutic strategies that could
help to maintain or even improve residual hearing when human deafness is related to
IGF-1 deficiencyThis work was supported by the Spanish Ministerio de Economía
y Competitividad (MINECO; SAF2016-788898-C2-1R) to JJ and
VF-S; Seventh Framework Programme (FP7)-HEALTH-
2012-INNOVATON (#304925) to JJ; CIBERER/FEDER
ACCI-ER16P5AC7091 and ER17P5AC7612 to LR-R;
and Spanish MINECO/FEDER (SAF2014-53979-R), FP7-
PEOPLE-2013-IAPP TARGEAR, CIBERER/FEDER (ACCIER16P5AC7091
and ER17P5AC7612) to IV-N. LR-R holds a
contract supported by CIBERER (Institute of Health Carlos III)
co-financed with FEDER fund
Ciberacoso, uso problemático de redes sociales virtuales e ideación suicida en adolescentes
Los avances tecnológicos han posibilitado el uso y abuso de las TICS en la adolescencia. Entre
los usos inadecuados se encuentran el Ciberacoso y el Uso Problemático de las Redes Sociales
Virtuales (en adelante UPRSV). El objetivo de este trabajo es analizar las relaciones entre victimización,
el UPRSV y la ideación suicida en adolescentes en función del género. La muestra
está constituida por 2399 adolescentes de ambos sexos de 12 a 18 años (M = 14. 63; DT = 1.91).
Participaron 19 centros educativos, de los cuales 12 son de titularidad pública y 7 de titularidad
privada/concertada de las provincias que componen la región de Andalucía occidental. Se
realizó un muestro estratificado proporcional en función de los contextos rural y urbano. Los
instrumentos utilizados fueron la escala de cibervictimización (Buelga, Cava & Musitu, 2012),
la Escala de ideación suicida (Roberts, 1980) y la escala de UPRSV. Se calculó un MANOVA
factorial con el programa SPSS. Los resultados muestran una relación entre cibervictimización,
UPRSV y la ideación suicida. Además, se constataron diferencias en función del género
en las variables analizadas. Finalmente, se discuten los resultados y sus implicaciones con la
evidencia empírica para potenciar los programas de intervención en el ámbito de la cibervictimización
escolar teniendo en cuenta las diferencias en función del género, desde el trabajo
social educativo y comunitario
Allelopathic studies with furanocoumarins isolated from Ducrosia anethifolia. vitro and in silico investigations to protect legumes, rice and grain crops
Six different furanocoumarins were isolated from the aerial parts of Ducrosia anethifolia and tested in vitro for plant cell elongation in etiolated wheat coleoptile. They were also tested for their ability to control three different weeds: ribwort plantain, annual ryegrass, and common purslane. These compounds exhibited strong inhibition of plant cell elongation. In the case of (+)-heraclenin, the IC50 was lower than 20 mu M, indicating a better inhibition than the positive control Logran (R). Computational experiments for docking and molecular dynamics revealed for the investigated furanocoumarins bearing an epoxide moiety an improved fitting and stronger interaction with the auxin-like TIR1 ubiquitin ligase. Furthermore, the formed inhibition complex remained also stable during dynamic evaluation. Bidental interaction at the active site, along with an extended hydrogen-bond lifetime, explained the enhanced activity of the epoxides. The in vitro weed bioassay results showed that Plantago lan-ceolata was the most affected weed for germination, root, and shoot development. In addition, (+)-heraclenin displayed better inhibition values than positive control even at 300 mu M concentration
Allelopathic studies with furanocoumarins isolated from Ducrosia anethifolia. In vitro and in silico investigations to protect legumes, rice and grain crops
Neuroglial Involvement in Abnormal Glutamate Transport in the Cochlear Nuclei of the Igf1−/− Mouse
Insulin-like growth factor 1 (IGF-1) is a powerful regulator of synaptic activity and a deficit in this protein has a profound impact on neurotransmission, mostly on excitatory synapses in both the developing and mature auditory system. Adult Igf1−/− mice are animal models for the study of human syndromic deafness; they show altered cochlear projection patterns into abnormally developed auditory neurons along with impaired glutamate uptake in the cochlear nuclei, phenomena that probably reflect disruptions in neuronal circuits. To determine the cellular mechanisms that might be involved in regulating excitatory synaptic plasticity in 4-month-old Igf1−/− mice, modifications to neuroglia, astroglial glutamate transporters (GLTs) and metabotropic glutamate receptors (mGluRs) were assessed in the cochlear nuclei. The Igf1−/− mice show significant decreases in IBA1 (an ionized calcium-binding adapter) and glial fibrillary acidic protein (GFAP) mRNA expression and protein accumulation, as well as dampened mGluR expression in conjunction with enhanced glutamate transporter 1 (GLT1) expression. By contrast, no differences were observed in the expression of glutamate aspartate transporter (GLAST) between these Igf1−/− mice and their heterozygous or wildtype littermates. These observations suggest that congenital IGF-1 deficiency may lead to alterations in microglia and astrocytes, an upregulation of GLT1, and the downregulation of groups I, II and III mGluRs. Understanding the molecular, biochemical and morphological mechanisms underlying neuronal plasticity in a mouse model of hearing deficits will give us insight into new therapeutic strategies that could help to maintain or even improve residual hearing when human deafness is related to IGF-1 deficiency
Biological activities and chemical composition of methanolic extracts of selected Autochthonous microalgae strains from the Red Sea
Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 mu g/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and -carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.National Science, Technology and Innovation Program of King Abdulaziz Medical City for Science and Technology, Riyadh, Saudi Arabia [NPST, 11-ENE 1719-02]; Foundation for Science and Technology (FCT), Portugal [SFRH/BD/78062/2011]; FCT [IF/00049/2012, SFRH/BPD/86071/2012, Pest-OE/QUI/UI0612/2013]info:eu-repo/semantics/publishedVersio
Hydrolysable Tannins and Biological Activities of Meriania hernandoi and Meriania nobilis (Melastomataceae)
A bio-guided study of leaf extracts allowed the isolation of two new macrobicyclic
hydrolysable tannins, namely merianin A (1) and merianin B (2), and oct-1-en-3-yl
b-xylopyranosyl-(1”-6’)-b-glucopyranoside (3) from Meriania hernandoi, in addition to 11 known
compounds reported for the first time in the Meriania genus. The structures were elucidated by
spectroscopic analyses including one- and two-dimensional NMR techniques and mass spectrometry.
The bioactivities of the compounds were determined by measuring the DPPH radical scavenging
activity and by carrying out antioxidant power assays (FRAP), etiolated wheat coleoptile assays
and phytotoxicity assays on the standard target species Lycopersicum esculentum W. (tomato).
Compounds 1 and 2 exhibited the best free radical scavenging activities, with FRS50 values of
2.0 and 1.9 M, respectively
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