Carlos Fernandez | Universidad de Alcala (original) (raw)
Papers by Carlos Fernandez
The Science of the total environment, Jan 20, 2000
Three biochemical parameters, DNA quantification in soil samples and two enzymatic activities, be... more Three biochemical parameters, DNA quantification in soil samples and two enzymatic activities, beta-galactosidase and dehydrogenase have been assessed as potential end-points for the use in cost-effective toxicity tests on soil microorganisms. The assessment included the development of a classical dose-response 24-h assay and the incorporation of measurements of the effects on microbial activities in soil column leaching studies and multispecies miniaturised terrestrial systems (MTS). Four different chemicals, copper, a new herbicide, thiabendazole and fenthion were studied. A rapid fluorescence DNA quantification technique did not produce adequate responses. The efforts to quantify DNA after extraction and clean-up procedures failed due to the presence of humic acids. From the protocol of the technique one could see that the technical procedure is time-consuming and expensive and, for this reason, not suitable for use as a parameter in rapid and cost-effective tests. However, the e...
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Icarus, 2010
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Planetary and Space Science, 2000
Mercurian lobate scarps are interpreted to be the surface expressions of thrust faults formed by ... more Mercurian lobate scarps are interpreted to be the surface expressions of thrust faults formed by planetary cooling and contraction, which deformed the crust down to the brittle–ductile transition (BDT) depth at the time of faulting. In this work we have used a forward modeling procedure in order to analyze the relation between scarp topography and fault geometries and depths associated
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Soil & Sediment Contamination, 2009
Ivermectin is a worldwide used antiparasitic compound acting against both endo- and ecto parasite... more Ivermectin is a worldwide used antiparasitic compound acting against both endo- and ecto parasites of livestock. Ivermectin can reach the environment through the direct emission of dung from livestock on pasture and via manure application on agricultural lands. Due to its very high acute toxicity to many invertebrates, especially to D. magna, the excretion profile of ivermectin in dung after
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The Biochemical journal, Jan 15, 2002
Dietary phytosterols are cholesterol-lowering agents that interfere with the intestinal absorptio... more Dietary phytosterols are cholesterol-lowering agents that interfere with the intestinal absorption of cholesterol. In the present study, we have studied their effects on cholesterol biosynthesis in human cells, particularly in the sterol-conversion pathway. For this, both Caco-2 (intestinal mucosa) and HL-60 (promyelocytic) human cell lines were incubated with [(14)C]acetate, and the incorporation of radioactivity into sterols was determined using HPLC and radioactivity detection online. Sterols containing a double bond at C-22 in the side chain (stigmasterol, brassicasterol and ergosterol) dramatically inhibited the activity of sterol Delta(24)-reductase, as indicated by the decrease in radioactivity incorporation into cholesterol and the accumulation of its precursors (mainly desmosterol). Phytosterols with the saturated side chain (beta-sitosterol and campesterol) were inactive in this regard. The inhibition of sterol (24)-reductase was confirmed in rat liver microsomes by using ...
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Molecular pharmacology, 2003
The administration of the H(2)O(2)-specific scavenger catalase attenuated the generation of apopt... more The administration of the H(2)O(2)-specific scavenger catalase attenuated the generation of apoptosis by the antitumor drugs etoposide, camptothecin, doxorubicin, and cisplatin in U-937 human promonocytic cells. By contrast, the antioxidant potentiated the generation of apoptosis by the inducers of the stress response, heat shock and cadmium, in this and other myeloid cell types. Catalase also increased the heat shock-provoked stimulation of caspase-3 and -9 activities, as well as the release of cytochrome c from mitochondria to the cytosol. The potentiation of cell death by catalase correlated with its capacity to inhibit the stress response, as demonstrated by the suppression of 70- or 27-kDa heat-shock protein expression and the inhibition of heat-shock transcription factor 1 binding activity. Conversely, the toxicity of catalase plus heat shock was attenuated when the cells were preconditioned with a soft heating, which elevated the 70-kDa heat-shock protein levels. By contrast ...
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Retina (Philadelphia, Pa.), 2004
Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for RETINA. Enter you... more Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for RETINA. Enter your Email address: Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your ...
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Journal of lipid research, 2005
Cholesterol is a major lipid component of the plasma membrane in animal cells. In addition to its... more Cholesterol is a major lipid component of the plasma membrane in animal cells. In addition to its structural requirement, cholesterol is essential in cell proliferation and other cell processes. The aim of the present study was to elucidate the stringency of the requirement for cholesterol as a regulator of proliferation and cell cycle progression, compared with other sterols of the cholesterol biosynthesis pathway. Human promyelocytic HL-60 cells were cultured in cholesterol-free medium and treated with different distal inhibitors of cholesterol biosynthesis (zaragozic acid, SKF 104976, SR 31747, BM 15766, and AY 9944), which allow the synthesis of isoprenoid derivatives and different sets of sterol intermediates, but not cholesterol. The results showed that only the inhibition of sterol Delta7-reductase was compatible with cell proliferation. Blocking cholesterol biosynthesis upstream of this enzyme resulted in the inhibition of cell proliferation and cell cycle arrest selectively...
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Journal of nanoscience and nanotechnology, 2006
Monodispersive gold nanoparticles can be synthesized by a dropwise addition of a reducing agent m... more Monodispersive gold nanoparticles can be synthesized by a dropwise addition of a reducing agent microemulsion to a gold ion microemulsion followed by immediate stabilization with 1-decanethiol. No size-selective precipitations or digestive ripening procedures are necessary. There is no need for metal functionalization of the surfactant AOT. Gold nanoparticles with an average size of 3.8 nm and a relative size dispersion of 5.4% were observed using n-heptane as a solvent. It seems possible to adjust the nanoparticle size by small changes in the carbon chain length of the solvent. Self-assembled 2D and 3D arrays of gold nanoparticles with adjustable sizes have been obtained on carbon-coated copper grids and on a silicon wafer. The arrays have good crystallinity as evidenced by the external morphology and transmission electron diffraction results. The size of the gold nanoparticle 3D arrays depends on the immersion time and can be greater than 15 microm. This approach could be used to ...
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Small (Weinheim an der Bergstrasse, Germany), 2006
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Langmuir : the ACS journal of surfaces and colloids, Jan 21, 2010
The considerable number of important physical properties, including optical, electronic, and magn... more The considerable number of important physical properties, including optical, electronic, and magnetic properties, of Prussian blue (PB) analogues have attracted fundamental and industrial interest. Nevertheless, the gas sorption properties of PB coordination compounds were only investigated very recently. In this work, we report the synthesis and gas sorption properties of PB nanocomposites with different size and shape obtained by using poly(vinylpyrrolidone) (PVP), chitosan, and dioctyl sodium sulfosuccinate (AOT) as stabilizers and structure directing agents. All three porous nanocrystals show high and selective CO(2) adsorption over CH(4) or N(2). No distinct relationship was found between the size (or shape) of the nanosorbents and their gas uptake capacities. To our knowledge, this is the first report on the use of PB nanocomposites for CO(2) capture applications.
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Journal of the American Chemical Society, Jan 6, 2012
Krypton (Kr) and xenon (Xe) adsorption on two partially fluorinated metal-organic frameworks (FMO... more Krypton (Kr) and xenon (Xe) adsorption on two partially fluorinated metal-organic frameworks (FMOFCu and FMOFZn) with different cavity size and topologies are reported. FMOFCu shows an inversion in sorption selectivity toward Kr at temperatures below 0 °C while FMOFZn does not. The 1D microtubes packed along the (101) direction connected through small bottleneck windows in FMOFCu appear to be the reason for this peculiar behavior. The FMOFCu shows an estimated Kr/Xe selectivity of 36 at 0.1 bar and 203 K.
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Scientific reports, 2014
Crystalline metal organic framework (MOF) materials containing interconnected porosity can be che... more Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCN...
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Reumatología Clínica (English Edition), 2011
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Small, 2009
The ability to process and purify engineered nanomaterials using near critical or supercritical f... more The ability to process and purify engineered nanomaterials using near critical or supercritical fluids (NcFs or ScFs) has enormous potential for the application at various stages of the development of green nanomaterials. The dispersibility of octanethiol-stabilized gold nanocrystals of different core sizes is explored, which were chosen to serve as model nanomaterials of general interest in compressed ethane and propane over a wide range of fluid conditions. Both solvents have enormous potential for the environmentally benign processing and transport of engineered nanomaterials due to their nominal toxicity and high degree of tunability and processability that can essentially eliminate solvent waste. The dispersibility is determined by measuring the absorption spectra of dispersions of various sizes of nanocrystals in NcFs. To better understand the obtained results three models, the total interaction theory, the sedimentation coefficient equation, and the Chrastil method, are discussed. Nanoparticle dispersibility versus density plots are strongly dependent on nanoparticle size and solvent conditions, with the dispersion of larger nanocrystals more dependent on changes of pressure or density at a given temperature. For the range of nanoparticle sizes studied, compressed ethane at 25 degrees C leads to a greater tunability of nanoparticle dispersion when compared with compressed propane at 65 degrees C. For equivalent pressures, compressed propane is found to provide better solubility than ethane due to its higher density. The results quantitatively demonstrate that NcFs can offer pressure-tunable, size-selective control of nanoparticle solvation and transport at easily obtainable temperature and pressure conditions. These capabilities provide clear advantages over conventional solvents and direct application to various nanomaterials processes, such as synthesis, separation, transport, and purification of nanocrystals.
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The Science of the total environment, Jan 20, 2000
Three biochemical parameters, DNA quantification in soil samples and two enzymatic activities, be... more Three biochemical parameters, DNA quantification in soil samples and two enzymatic activities, beta-galactosidase and dehydrogenase have been assessed as potential end-points for the use in cost-effective toxicity tests on soil microorganisms. The assessment included the development of a classical dose-response 24-h assay and the incorporation of measurements of the effects on microbial activities in soil column leaching studies and multispecies miniaturised terrestrial systems (MTS). Four different chemicals, copper, a new herbicide, thiabendazole and fenthion were studied. A rapid fluorescence DNA quantification technique did not produce adequate responses. The efforts to quantify DNA after extraction and clean-up procedures failed due to the presence of humic acids. From the protocol of the technique one could see that the technical procedure is time-consuming and expensive and, for this reason, not suitable for use as a parameter in rapid and cost-effective tests. However, the e...
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Icarus, 2010
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Planetary and Space Science, 2000
Mercurian lobate scarps are interpreted to be the surface expressions of thrust faults formed by ... more Mercurian lobate scarps are interpreted to be the surface expressions of thrust faults formed by planetary cooling and contraction, which deformed the crust down to the brittle–ductile transition (BDT) depth at the time of faulting. In this work we have used a forward modeling procedure in order to analyze the relation between scarp topography and fault geometries and depths associated
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Soil & Sediment Contamination, 2009
Ivermectin is a worldwide used antiparasitic compound acting against both endo- and ecto parasite... more Ivermectin is a worldwide used antiparasitic compound acting against both endo- and ecto parasites of livestock. Ivermectin can reach the environment through the direct emission of dung from livestock on pasture and via manure application on agricultural lands. Due to its very high acute toxicity to many invertebrates, especially to D. magna, the excretion profile of ivermectin in dung after
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The Biochemical journal, Jan 15, 2002
Dietary phytosterols are cholesterol-lowering agents that interfere with the intestinal absorptio... more Dietary phytosterols are cholesterol-lowering agents that interfere with the intestinal absorption of cholesterol. In the present study, we have studied their effects on cholesterol biosynthesis in human cells, particularly in the sterol-conversion pathway. For this, both Caco-2 (intestinal mucosa) and HL-60 (promyelocytic) human cell lines were incubated with [(14)C]acetate, and the incorporation of radioactivity into sterols was determined using HPLC and radioactivity detection online. Sterols containing a double bond at C-22 in the side chain (stigmasterol, brassicasterol and ergosterol) dramatically inhibited the activity of sterol Delta(24)-reductase, as indicated by the decrease in radioactivity incorporation into cholesterol and the accumulation of its precursors (mainly desmosterol). Phytosterols with the saturated side chain (beta-sitosterol and campesterol) were inactive in this regard. The inhibition of sterol (24)-reductase was confirmed in rat liver microsomes by using ...
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Molecular pharmacology, 2003
The administration of the H(2)O(2)-specific scavenger catalase attenuated the generation of apopt... more The administration of the H(2)O(2)-specific scavenger catalase attenuated the generation of apoptosis by the antitumor drugs etoposide, camptothecin, doxorubicin, and cisplatin in U-937 human promonocytic cells. By contrast, the antioxidant potentiated the generation of apoptosis by the inducers of the stress response, heat shock and cadmium, in this and other myeloid cell types. Catalase also increased the heat shock-provoked stimulation of caspase-3 and -9 activities, as well as the release of cytochrome c from mitochondria to the cytosol. The potentiation of cell death by catalase correlated with its capacity to inhibit the stress response, as demonstrated by the suppression of 70- or 27-kDa heat-shock protein expression and the inhibition of heat-shock transcription factor 1 binding activity. Conversely, the toxicity of catalase plus heat shock was attenuated when the cells were preconditioned with a soft heating, which elevated the 70-kDa heat-shock protein levels. By contrast ...
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Retina (Philadelphia, Pa.), 2004
Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for RETINA. Enter you... more Close Window. Close Window. Thank you for choosing to subscribe to the eTOC for RETINA. Enter your Email address: Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your ...
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Journal of lipid research, 2005
Cholesterol is a major lipid component of the plasma membrane in animal cells. In addition to its... more Cholesterol is a major lipid component of the plasma membrane in animal cells. In addition to its structural requirement, cholesterol is essential in cell proliferation and other cell processes. The aim of the present study was to elucidate the stringency of the requirement for cholesterol as a regulator of proliferation and cell cycle progression, compared with other sterols of the cholesterol biosynthesis pathway. Human promyelocytic HL-60 cells were cultured in cholesterol-free medium and treated with different distal inhibitors of cholesterol biosynthesis (zaragozic acid, SKF 104976, SR 31747, BM 15766, and AY 9944), which allow the synthesis of isoprenoid derivatives and different sets of sterol intermediates, but not cholesterol. The results showed that only the inhibition of sterol Delta7-reductase was compatible with cell proliferation. Blocking cholesterol biosynthesis upstream of this enzyme resulted in the inhibition of cell proliferation and cell cycle arrest selectively...
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Journal of nanoscience and nanotechnology, 2006
Monodispersive gold nanoparticles can be synthesized by a dropwise addition of a reducing agent m... more Monodispersive gold nanoparticles can be synthesized by a dropwise addition of a reducing agent microemulsion to a gold ion microemulsion followed by immediate stabilization with 1-decanethiol. No size-selective precipitations or digestive ripening procedures are necessary. There is no need for metal functionalization of the surfactant AOT. Gold nanoparticles with an average size of 3.8 nm and a relative size dispersion of 5.4% were observed using n-heptane as a solvent. It seems possible to adjust the nanoparticle size by small changes in the carbon chain length of the solvent. Self-assembled 2D and 3D arrays of gold nanoparticles with adjustable sizes have been obtained on carbon-coated copper grids and on a silicon wafer. The arrays have good crystallinity as evidenced by the external morphology and transmission electron diffraction results. The size of the gold nanoparticle 3D arrays depends on the immersion time and can be greater than 15 microm. This approach could be used to ...
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Small (Weinheim an der Bergstrasse, Germany), 2006
Bookmarks Related papers MentionsView impact
Langmuir : the ACS journal of surfaces and colloids, Jan 21, 2010
The considerable number of important physical properties, including optical, electronic, and magn... more The considerable number of important physical properties, including optical, electronic, and magnetic properties, of Prussian blue (PB) analogues have attracted fundamental and industrial interest. Nevertheless, the gas sorption properties of PB coordination compounds were only investigated very recently. In this work, we report the synthesis and gas sorption properties of PB nanocomposites with different size and shape obtained by using poly(vinylpyrrolidone) (PVP), chitosan, and dioctyl sodium sulfosuccinate (AOT) as stabilizers and structure directing agents. All three porous nanocrystals show high and selective CO(2) adsorption over CH(4) or N(2). No distinct relationship was found between the size (or shape) of the nanosorbents and their gas uptake capacities. To our knowledge, this is the first report on the use of PB nanocomposites for CO(2) capture applications.
Bookmarks Related papers MentionsView impact
Journal of the American Chemical Society, Jan 6, 2012
Krypton (Kr) and xenon (Xe) adsorption on two partially fluorinated metal-organic frameworks (FMO... more Krypton (Kr) and xenon (Xe) adsorption on two partially fluorinated metal-organic frameworks (FMOFCu and FMOFZn) with different cavity size and topologies are reported. FMOFCu shows an inversion in sorption selectivity toward Kr at temperatures below 0 °C while FMOFZn does not. The 1D microtubes packed along the (101) direction connected through small bottleneck windows in FMOFCu appear to be the reason for this peculiar behavior. The FMOFCu shows an estimated Kr/Xe selectivity of 36 at 0.1 bar and 203 K.
Bookmarks Related papers MentionsView impact
Scientific reports, 2014
Crystalline metal organic framework (MOF) materials containing interconnected porosity can be che... more Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCN...
Bookmarks Related papers MentionsView impact
Reumatología Clínica (English Edition), 2011
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Small, 2009
The ability to process and purify engineered nanomaterials using near critical or supercritical f... more The ability to process and purify engineered nanomaterials using near critical or supercritical fluids (NcFs or ScFs) has enormous potential for the application at various stages of the development of green nanomaterials. The dispersibility of octanethiol-stabilized gold nanocrystals of different core sizes is explored, which were chosen to serve as model nanomaterials of general interest in compressed ethane and propane over a wide range of fluid conditions. Both solvents have enormous potential for the environmentally benign processing and transport of engineered nanomaterials due to their nominal toxicity and high degree of tunability and processability that can essentially eliminate solvent waste. The dispersibility is determined by measuring the absorption spectra of dispersions of various sizes of nanocrystals in NcFs. To better understand the obtained results three models, the total interaction theory, the sedimentation coefficient equation, and the Chrastil method, are discussed. Nanoparticle dispersibility versus density plots are strongly dependent on nanoparticle size and solvent conditions, with the dispersion of larger nanocrystals more dependent on changes of pressure or density at a given temperature. For the range of nanoparticle sizes studied, compressed ethane at 25 degrees C leads to a greater tunability of nanoparticle dispersion when compared with compressed propane at 65 degrees C. For equivalent pressures, compressed propane is found to provide better solubility than ethane due to its higher density. The results quantitatively demonstrate that NcFs can offer pressure-tunable, size-selective control of nanoparticle solvation and transport at easily obtainable temperature and pressure conditions. These capabilities provide clear advantages over conventional solvents and direct application to various nanomaterials processes, such as synthesis, separation, transport, and purification of nanocrystals.
Bookmarks Related papers MentionsView impact