Alfonso Otero - Academia.edu (original) (raw)
Papers by Alfonso Otero
Metallurgical and Materials Transactions B, 2009
Minerals Engineering, 2011
In the quest of new, less hazardous, and more ambient-friendly froth flotation reagents, the use ... more In the quest of new, less hazardous, and more ambient-friendly froth flotation reagents, the use of biosolids or humic acids as both collector and frother for the concentration of copper sulphide ores was investigated. Rougher flotation tests were conducted in Denver cells on a laboratory scale, and metallurgical indicators such as copper recovery, copper concentrate grade, and concentration and enrichment ratios were compared with those obtained under similar conditions but using conventional collectors and frothers for the industrial flotation of copper sulphide ores. With a dosage of 10% (w/w) biosolids, copper recovery and grade were 26% and 0.81%, respectively. The copper recovery and grade obtained with 1.5% (w/w) salt of humic acids were 29.7% and 3.5%, respectively. A significantly higher copper recovery (65.1%) was obtained with conventional industrial collectors and frothers, but the grade was also low (3.1% Cu). With the same dosage of humic substances, humic acid show that the flotation rate constant was significantly higher (0.2 min À1) than that obtained with the same dosage of biosolids (0.09 min À1). These results indicate that humic acids have more affinity than biosolids for copper-containing mineral species, and also show that biosolids and humic acids could be used as both collector and frother in the sulphide mineral concentration process by froth flotation. Because the distribution of iron in the concentrate obtained with biosolids is highest, these materials seem to have more affinity for pyrite.
Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2010
The kinetics and reaction mechanism of the flash oxidation of +35/–53 μm molybdenite particles in... more The kinetics and reaction mechanism of the flash oxidation of +35/–53 μm molybdenite particles in air, as well as in 25, 50, and 100 pct oxygen higher than 800 K, has been investigated using a stagnant gas reactor and a laminar flow reactor coupled to a fast-response, two-wavelength pyrometer. The changes in the morphology and in the chemical composition of partially reacted particles were also investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal analysis (DTA), and electron microprobe. High-speed photography was also used to characterize the particle combustion phenomena. The effects of oxygen concentration and gas temperature on ignition and peak combustion temperatures were studied. The experimental results indicate that MoS2 goes through a process of ignition/combustion with the formation of gaseous MoO3 and SO2 with no evidence of formation of a molten phase, although the reacting molybdenite particles reach temperatures much higher ...
Chronobiology International
Current hypertension guidelines fail to provide a recommendation on when-to-treat, thus disregard... more Current hypertension guidelines fail to provide a recommendation on when-to-treat, thus disregarding relevant circadian rhythms that regulate blood pressure (BP) level and 24 h patterning and medication pharmacokinetics and pharmacodynamics. The ideal purpose of ingestion-time (chronopharmacology, i.e. biological rhythm-dependent effects on the kinetics and dynamics of medications, and chronotherapy, i.e. the timing of pharmaceutical and other treatments to optimize efficacy and safety) trials should be to explore the potential impact of endogenous circadian rhythms on the effects of medications. Such investigations and outcome trials mandate adherence to the basic standards of human chronobiology research. In-depth review of the more than 150 human hypertension pharmacology and therapeutic trials published since 1974 that address the differential impact of upon-waking/morning versus at-bedtime/evening schedule of treatment reveals diverse protocols of sometimes suboptimal or defective design and conduct. Many have been "time-of-day," i.e. morning versus evening, rather than circadian-time-based, and some relied on wake-time office BP rather than around-the-clock ambulatory BP measurements (ABPM). Additionally, most past studies have been of too small sample size and thus statistically underpowered. As of yet, there has been no consensual agreement on the proper design, methods and conduct of such trials. This Position Statement recommends ingestion-time hypertension trials to follow minimum guidelines: (i) Recruitment of participants should be restricted to hypertensive individuals diagnosed according to ABPM diagnostic thresholds and of a comparable activity/sleep routine. (ii) Tested treatment-times should be selected according to internal biological time, expressed by the awakening and bed times of the sleep/wake ARTICLE HISTORY
Chronobiology International
Chronobiology International
European heart journal, Jan 10, 2018
Sleep-time blood pressure (BP) is a stronger risk factor for cardiovascular disease (CVD) events ... more Sleep-time blood pressure (BP) is a stronger risk factor for cardiovascular disease (CVD) events than awake and 24 h BP means, but the potential role of asleep BP as therapeutic target for diminishing CVD risk is uncertain. We investigated whether CVD risk reduction is most associated with progressive decrease of either office or ambulatory awake or asleep BP mean. We prospectively evaluated 18 078 individuals with baseline ambulatory BP ranging from normotension to hypertension. At inclusion and at scheduled visits (mainly annually) during follow-up, ambulatory BP was measured for 48 consecutive hours. During the 5.1-year median follow-up, 2311 individuals had events, including 1209 experiencing the primary outcome (composite of CVD death, myocardial infarction, coronary revascularization, heart failure, and stroke). The asleep systolic blood pressure (SBP) mean was the most significant BP-derived risk factor for the primary outcome [hazard ratio 1.29 (95% CI) 1.22-1.35 per SD elev...
Bitacora Arquitectura, Mar 10, 2012
Actas Del Ii Seminario Iberoamericano De Construccion Con Tierra Recurso Electronico Escuela Tecnica Superior De Arquitectura De Madrid 18 Y 19 De Septiembre De 2003 2004 Isbn 84 933016 9 8 Pags 114 125, 2004
Actas Del Ii Seminario Iberoamericano De Construccion Con Tierra Recurso Electronico Escuela Tecnica Superior De Arquitectura De Madrid 18 Y 19 De Septiembre De 2003 2004 Isbn 84 933016 9 8 Pags 126 136, 2004
Formalin-fixed tissues are an important source of biological samples for biomedical research. How... more Formalin-fixed tissues are an important source of biological samples for biomedical research. However, proteomics analysis of formalin-fixed tissues has been set aside by formalin-induced protein modifications, which reduce protein extraction efficiency. In this study, a two level full factorial experimental design (2 4) was used to determine the effects of the extracting conditions in the efficiency of protein recovery from formalin-fixed kidney samples. The following variables were assessed: temperature of extraction, pH of extraction, composition of the extracting buffer and the use ultrasonic energy applied with probe. It is clearly demonstrated that when hating and ultrasonic energy are used in conjunction, a 7-fold increase (p o 0.05) in protein extraction is obtained if compared to extracting conditions for which neither heating nor ultrasonic energy are used. The optimization study was done following the amount of protein extracted by UV (Nanodrop s technology, protein ABS at 280 nm) and by 1D SDS-PAGE. Extracts obtained with the optimized conditions were subjected to LC-MALDI MS/MS. A total of 112 proteins were identified.
Boletin Das Ciencias, 2005
... Cando este fluído alcanza o outro extremo transmite o sinal á dendrita. Os impulsos recibidos... more ... Cando este fluído alcanza o outro extremo transmite o sinal á dendrita. Os impulsos recibidos dende a sinapses súmanse ou réstanse á magnitude das variacións do potencial da membrana. Si as contribucións totais Page 3. ... James A. Freeman y David M. Skapura. Ed. ...
Nefrologia: publicacion oficial de la Sociedad Espanola Nefrologia
Metallurgical and Materials Transactions B, 2009
Minerals Engineering, 2011
In the quest of new, less hazardous, and more ambient-friendly froth flotation reagents, the use ... more In the quest of new, less hazardous, and more ambient-friendly froth flotation reagents, the use of biosolids or humic acids as both collector and frother for the concentration of copper sulphide ores was investigated. Rougher flotation tests were conducted in Denver cells on a laboratory scale, and metallurgical indicators such as copper recovery, copper concentrate grade, and concentration and enrichment ratios were compared with those obtained under similar conditions but using conventional collectors and frothers for the industrial flotation of copper sulphide ores. With a dosage of 10% (w/w) biosolids, copper recovery and grade were 26% and 0.81%, respectively. The copper recovery and grade obtained with 1.5% (w/w) salt of humic acids were 29.7% and 3.5%, respectively. A significantly higher copper recovery (65.1%) was obtained with conventional industrial collectors and frothers, but the grade was also low (3.1% Cu). With the same dosage of humic substances, humic acid show that the flotation rate constant was significantly higher (0.2 min À1) than that obtained with the same dosage of biosolids (0.09 min À1). These results indicate that humic acids have more affinity than biosolids for copper-containing mineral species, and also show that biosolids and humic acids could be used as both collector and frother in the sulphide mineral concentration process by froth flotation. Because the distribution of iron in the concentrate obtained with biosolids is highest, these materials seem to have more affinity for pyrite.
Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2010
The kinetics and reaction mechanism of the flash oxidation of +35/–53 μm molybdenite particles in... more The kinetics and reaction mechanism of the flash oxidation of +35/–53 μm molybdenite particles in air, as well as in 25, 50, and 100 pct oxygen higher than 800 K, has been investigated using a stagnant gas reactor and a laminar flow reactor coupled to a fast-response, two-wavelength pyrometer. The changes in the morphology and in the chemical composition of partially reacted particles were also investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal analysis (DTA), and electron microprobe. High-speed photography was also used to characterize the particle combustion phenomena. The effects of oxygen concentration and gas temperature on ignition and peak combustion temperatures were studied. The experimental results indicate that MoS2 goes through a process of ignition/combustion with the formation of gaseous MoO3 and SO2 with no evidence of formation of a molten phase, although the reacting molybdenite particles reach temperatures much higher ...
Chronobiology International
Current hypertension guidelines fail to provide a recommendation on when-to-treat, thus disregard... more Current hypertension guidelines fail to provide a recommendation on when-to-treat, thus disregarding relevant circadian rhythms that regulate blood pressure (BP) level and 24 h patterning and medication pharmacokinetics and pharmacodynamics. The ideal purpose of ingestion-time (chronopharmacology, i.e. biological rhythm-dependent effects on the kinetics and dynamics of medications, and chronotherapy, i.e. the timing of pharmaceutical and other treatments to optimize efficacy and safety) trials should be to explore the potential impact of endogenous circadian rhythms on the effects of medications. Such investigations and outcome trials mandate adherence to the basic standards of human chronobiology research. In-depth review of the more than 150 human hypertension pharmacology and therapeutic trials published since 1974 that address the differential impact of upon-waking/morning versus at-bedtime/evening schedule of treatment reveals diverse protocols of sometimes suboptimal or defective design and conduct. Many have been "time-of-day," i.e. morning versus evening, rather than circadian-time-based, and some relied on wake-time office BP rather than around-the-clock ambulatory BP measurements (ABPM). Additionally, most past studies have been of too small sample size and thus statistically underpowered. As of yet, there has been no consensual agreement on the proper design, methods and conduct of such trials. This Position Statement recommends ingestion-time hypertension trials to follow minimum guidelines: (i) Recruitment of participants should be restricted to hypertensive individuals diagnosed according to ABPM diagnostic thresholds and of a comparable activity/sleep routine. (ii) Tested treatment-times should be selected according to internal biological time, expressed by the awakening and bed times of the sleep/wake ARTICLE HISTORY
Chronobiology International
Chronobiology International
European heart journal, Jan 10, 2018
Sleep-time blood pressure (BP) is a stronger risk factor for cardiovascular disease (CVD) events ... more Sleep-time blood pressure (BP) is a stronger risk factor for cardiovascular disease (CVD) events than awake and 24 h BP means, but the potential role of asleep BP as therapeutic target for diminishing CVD risk is uncertain. We investigated whether CVD risk reduction is most associated with progressive decrease of either office or ambulatory awake or asleep BP mean. We prospectively evaluated 18 078 individuals with baseline ambulatory BP ranging from normotension to hypertension. At inclusion and at scheduled visits (mainly annually) during follow-up, ambulatory BP was measured for 48 consecutive hours. During the 5.1-year median follow-up, 2311 individuals had events, including 1209 experiencing the primary outcome (composite of CVD death, myocardial infarction, coronary revascularization, heart failure, and stroke). The asleep systolic blood pressure (SBP) mean was the most significant BP-derived risk factor for the primary outcome [hazard ratio 1.29 (95% CI) 1.22-1.35 per SD elev...
Bitacora Arquitectura, Mar 10, 2012
Actas Del Ii Seminario Iberoamericano De Construccion Con Tierra Recurso Electronico Escuela Tecnica Superior De Arquitectura De Madrid 18 Y 19 De Septiembre De 2003 2004 Isbn 84 933016 9 8 Pags 114 125, 2004
Actas Del Ii Seminario Iberoamericano De Construccion Con Tierra Recurso Electronico Escuela Tecnica Superior De Arquitectura De Madrid 18 Y 19 De Septiembre De 2003 2004 Isbn 84 933016 9 8 Pags 126 136, 2004
Formalin-fixed tissues are an important source of biological samples for biomedical research. How... more Formalin-fixed tissues are an important source of biological samples for biomedical research. However, proteomics analysis of formalin-fixed tissues has been set aside by formalin-induced protein modifications, which reduce protein extraction efficiency. In this study, a two level full factorial experimental design (2 4) was used to determine the effects of the extracting conditions in the efficiency of protein recovery from formalin-fixed kidney samples. The following variables were assessed: temperature of extraction, pH of extraction, composition of the extracting buffer and the use ultrasonic energy applied with probe. It is clearly demonstrated that when hating and ultrasonic energy are used in conjunction, a 7-fold increase (p o 0.05) in protein extraction is obtained if compared to extracting conditions for which neither heating nor ultrasonic energy are used. The optimization study was done following the amount of protein extracted by UV (Nanodrop s technology, protein ABS at 280 nm) and by 1D SDS-PAGE. Extracts obtained with the optimized conditions were subjected to LC-MALDI MS/MS. A total of 112 proteins were identified.
Boletin Das Ciencias, 2005
... Cando este fluído alcanza o outro extremo transmite o sinal á dendrita. Os impulsos recibidos... more ... Cando este fluído alcanza o outro extremo transmite o sinal á dendrita. Os impulsos recibidos dende a sinapses súmanse ou réstanse á magnitude das variacións do potencial da membrana. Si as contribucións totais Page 3. ... James A. Freeman y David M. Skapura. Ed. ...
Nefrologia: publicacion oficial de la Sociedad Espanola Nefrologia