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1.
Artículo en Inglés | MEDLINE | ID: mdl-34948576

RESUMEN

Natural resources are becoming scarcer and, together with the growth of the population, a widespread situation of overexploitation is inevitable that has become the biggest challenge for today's world. In this context, the agri-food sector has a considerable environmental impact in terms of water and energy consumption. For about two decades, the Water-Energy-Food Nexus (WEF) Nexus has been trying to address this problem, focusing on efficient interrelationships among these dimensions. The objective of this work is to analyse the evolution of research on WEF Nexus in the agri-food sector and its development in scientific databases. For that purpose, a bibliometric study was carried out with publications obtained from the Scopus database, examining the main journals, authors, institutions, countries, subject areas, funding sponsors, and keywords. Moreover, a final section is specifically dedicated to the agri-food innovations in WEF Nexus in order to explore innovative aspects to effectively overcome technical barriers that hinder a real implementation of the Nexus approach. The results show that, over the past decade, Nexus research in the agri-food sector has been growing exponentially. The top country in this field is USA, the most studied area is environmental science, and the most relevant keywords are "energy use", "water budget", "food security", "sustainable development", and "water resources".


Asunto(s)
Abastecimiento de Agua , Agua , Alimentos , Abastecimiento de Alimentos , Recursos Hídricos
2.
Int J Clin Pract ; 75(9): e14479, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34107137

RESUMEN

INTRODUCTION: In addition to respiratory support needs, patients' characteristics to guide indication or timing of corticosteroid treatment in COVID-19 patients are not completely established. This study aimed to evaluate the impact of methylprednisolone on mortality rate in patients with COVID-19 pneumonia-induced severe systemic inflammation (PI-SSI). METHODS: Between 9 March and 5 May 2020 (final follow-up on 2 July 2020), a retrospective cohort study was conducted in hospitalised patients with COVID-19 PI-SSI (≥2 inflammatory biomarkers [IBs]: temperature ≥38℃, lymphocyte ≤800 cell/µL, C-reactive protein ≥100 mg/L, lactate dehydrogenase ≥300 units/L, ferritin ≥1000 mcg/L, D-dimer ≥500 ng/mL). Patients received 0.5-1.0 mg/kg of methylprednisolone for 5-10 days or standard of care. The primary outcome was 28-day all-cause mortality. Secondary outcomes included ≥2 points improvement on a 7-item WHO-scale (Day 14), transfer to intensive care unit (ICU) (Day 28) and adverse effects. Kaplan-Meier method and Cox proportional hazard regression were implemented to analyse the time to event outcomes. RESULTS: A total of 142 patients (corticosteroid group n = 72, control group n = 70) were included. A significant reduction in 28-day all-cause mortality was shown with methylprednisolone in patients with respiratory support (HR: 0.15; 95% CI 0.03-0.71), with ≥3 (HR: 0.17; 95% CI 0.05-0.61) or ≥4 altered IB (HR: 0.15; 95% CI 0.04-0.54) and in patients with both respiratory support and ≥3 (HR: 0.11; 95% CI 0.02-0.53] or ≥4 altered IB (HR: 0.14; 95% CI 0.04-0.51). No significant differences were found in secondary outcomes. CONCLUSION: Intermediate to high doses of methylprednisolone, initiated between 5 and 12 days after symptom onset, was associated with a significant reduction in 28-day all-cause mortality in patients with COVID-19 pneumonia and ≥3 o ≥ 4 altered IB, independently of the need of respiratory support.


Asunto(s)
COVID-19 , Metilprednisolona , Humanos , Inflamación , Estudios Retrospectivos , SARS-CoV-2
3.
Artículo en Inglés | MEDLINE | ID: mdl-32102209

RESUMEN

Understanding eco-innovation is an essential endeavor to achieve global sustainable development. In this sense, further research on implementation is needed to expand knowledge beyond current boundaries. The aim of this paper is to contribute to this debate by conducting an original multidimensional analysis using Spanish agri-food sector data. The empirical methodology applies a combination of descriptive statistics, cluster analysis and the chi-squared test. Two groups of well-differentiated eco-innovative firms are identified, those with high and low eco-innovation implementation levels. Quality certifications, environmental consulting and cooperation with stakeholders are the variables that contribute most to distinguishing these two groups. The results also reveal that operating income volume, number of employees and commercialization volume are key factors to become more eco-innovative. In this sense, larger firms are found to have a higher level of eco-innovation implementation than small- and medium-sized enterprises. The main contributions of this work are fourfold. Firstly, it presents a comprehensive framework of eco-innovation implementation in its four dimensions (product, process, organizational and marketing). Secondly, it fills existing gaps in the literature by analyzing green organizational and marketing eco-practices. Thirdly, it expands the sectorial scope of eco-innovation research primarily focused on high-tech sectors. Finally, this study makes it possible to design certain policies for public and private decision makers.


Asunto(s)
Agricultura , Conservación de los Recursos Naturales/métodos , Abastecimiento de Alimentos , Desarrollo Sostenible , Adolescente , Adulto , Análisis por Conglomerados , Humanos , Persona de Mediana Edad , España , Encuestas y Cuestionarios , Adulto Joven
4.
Sensors (Basel) ; 19(3)2019 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-30691214

RESUMEN

This work describes a method for the metrological characterization of structured surfaces using a confocal microscope. The proposed method is based on the calculation of texture parameters established in ISO 25178-2:2012. To ensure the traceability of these parameters, a procedure for the calibration of the Z-axis of the confocal microscope is proposed. The calculation of uncertainty associated with each parameter employs the Monte Carlo method, as well as the concept of a virtual instrument. The validity of the algorithms has been verified through the use of synthetic data provided by the National Institute of Standards and Technology (NIST) and physical standards, with minimum differences being obtained between the certified values and calculated or measured values. Finally, using the proposed method, the topography of a structured surface manufactured by laser machining is evaluated, obtaining the most used roughness parameters, as well as their measurement uncertainties and possible correlations. In general, it can be affirmed that it is possible to obtain metrologically reliable results with the proposed method.

5.
Artículo en Inglés | MEDLINE | ID: mdl-30322194

RESUMEN

Food safety management in short supply chains of fruit and vegetables, controlled by large retailers, has been widely studied in the literature. However, when it comes to traditional long supply chains, which include a greater number of intermediaries and wholesalers who, in some cases, play a dual role as resellers and producers, the mechanisms which promote the use of safety certifications have yet to be clearly defined. The present study intended to fill this gap in the literature and shed light on the food safety level that exists in this channel. In addition, this work attempted to identify the existence of differences between both sales systems. For this purpose, the empirical research studied the most important variables that influence the food safety level of some of the main European fruit and vegetable wholesalers. A survey was thus designed and later applied to Spanish and French intermediaries working in key wholesale markets and in the southeast of Spain, which is the leading commercialization area of these products in Europe. The results revealed the positive influence of specific customers (big retailers) on establishing stricter safety controls within wholesale companies. It was also observed that specific wholesalers also play an important role in the system, namely those dedicated to importing, but which are also responsible for quality and safety inspection of agri-food products exported from third countries into the European Union.


Asunto(s)
Inocuidad de los Alimentos , Abastecimiento de Alimentos/normas , Frutas/normas , Verduras/normas , Certificación , Comercio , Abastecimiento de Alimentos/estadística & datos numéricos , Francia , Frutas/provisión & distribución , Humanos , Mercadotecnía , España , Encuestas y Cuestionarios , Verduras/provisión & distribución
6.
Materials (Basel) ; 11(9)2018 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-30135371

RESUMEN

The term additive manufacturing (AM) groups together a set of technologies with similar characteristics forming part of the Fourth Industrial Revolution. AM is being developed globally, as evidenced by the standards published by and the agreements between the ISO and the ASTM in 2013. The purpose of this paper is to anticipate the main changes that will occur in AM by 2030 as forecast by more than 100 Spanish experts through Delphi prospection performed in 2018. In this way, the areas, aspects, and business models with the greatest probabilities of occurrence are obtained. The need for technical experts with specific knowledge and skills requires changes to current training syllabuses. Such changes will enable students to have the profiles foreseen in these job trends. The encouragement of STEAM (Science, Technology, Engineering, Arts, and Mathematics) training through the introduction of AM in study plans may be an appropriate alternative. Finally, the consequences of the Fourth Industrial Revolution for the employment market and on jobs, particularly in Spain, are set out and the latest Spanish Research, Development, and Innovation (R&D + I) plans are summarized as the framework for the possible implementation and development of AM.

7.
MethodsX ; 5: 635-638, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30013946

RESUMEN

As sustainability is a philosophical concept, the evaluation of sustainability of an agri-system is underpinned by a philosophical understanding. Deconstruction is the qualitative methodology derived from philosophical science that allows to show what is hidden, to reveal the implicit meaning of a sustainability assessment tool. •Qualitative methodology of analysis.•Applicable to all kind of qualitative analysis.•Suitable for review article.

8.
Biotechnol Prog ; 34(4): 900-909, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29603901

RESUMEN

The growth rate of four strains of Pseudomonas putida, KT2440, KT2442, KTH2, and KTH2 (pESOX3), under different fluid dynamic conditions has been studied. The cultures were conducted in a stirred tank bioreactor by changing the stirrer speed. Several process variables, such as biomass concentration, dissolved oxygen concentration, oxygen mass transfer rate and oxygen uptake rate, have been measured or calculated. Also cell viability was determined by viable colony counting in Petri dishes and culture samples were subjected into a transmission electron microscopy analysis, in order to describe the integrity of the individual cells. The experimental results show that the genetically modified organisms, the strains KTH2 and KTH2 (pESOX3), present a different growth under low agitation conditions, and low oxygen supply level, while the growth of the wild type strains, KT2440 and KT2442, followed the typical sigmoidal evolution that could be described by the logistic equation. The presence of outer membrane vesicles has been observed in the GMO strains. When the cultures were conducted at low stirrer speed, and so at low oxygen transfer rate, these vesicles were detected, indicating the bacterial response to oxidative stress, caused by the catalytic activity of the HpaC enzyme. For all of the strains tested, no hydrodynamic stress has been detected, even at very high agitation levels. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:900-909, 2018.


Asunto(s)
Oxígeno/metabolismo , Pseudomonas putida/crecimiento & desarrollo , Pseudomonas putida/fisiología , Biomasa , Reactores Biológicos/microbiología
9.
J Environ Manage ; 204(Pt 1): 594-604, 2017 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-28942190

RESUMEN

Eco-efficiency is currently receiving ever increasing interest as an indicator of sustainability, as it links environmental and economic performances in productive activities. In agriculture these indicators and their determinants prove relevant due to the close ties in this activity between the use of often limited natural resources and the provision of basic goods for society. The present paper analyzes eco-efficiency at micro-level, focusing on small-scale family farms as the principal decision-making units (DMUs) of horticulture in southeast Spain, which represents over 30% of fresh vegetables produced in the country. To this end, Data Envelopment Analysis (DEA) framework is applied, computing several combinations of environmental pressures (water usage, phytosanitary contamination, waste management, etc.) and economic value added. In a second stage we analyze the influence of family farms' socio-economic and environmental features on eco-efficiency indicators, as endogenous variables, by using truncated regression and bootstrapping techniques. The results show major inefficiency in aspects such as waste management, among others, while there is relatively minor inefficiency in water usage and nitrogen balance. On the other hand, features such as product specialization, adoption of quality certifications, and belonging to a cooperative all have a positive influence on eco-efficiency. These results are deemed to be of interest to agri-food systems structured on small-scale producers, and they may prove useful to policy-makers as regards managing public environmental programs in agriculture.


Asunto(s)
Agricultura , Conservación de los Recursos Naturales , Granjas , Agricultura/métodos , Conservación de los Recursos Naturales/métodos , Ambiente , España
10.
Sensors (Basel) ; 16(10)2016 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-27754441

RESUMEN

Coordinate measuring machines (CMM) are main instruments of measurement in laboratories and in industrial quality control. A compensation error model has been formulated (Part I). It integrates error and uncertainty in the feature measurement model. Experimental implementation for the verification of this model is carried out based on the direct testing on a moving bridge CMM. The regression results by axis are quantified and compared to CMM indication with respect to the assigned values of the measurand. Next, testing of selected measurements of length, flatness, dihedral angle, and roundness features are accomplished. The measurement of calibrated gauge blocks for length or angle, flatness verification of the CMM granite table and roundness of a precision glass hemisphere are presented under a setup of repeatability conditions. The results are analysed and compared with alternative methods of estimation. The overall performance of the model is endorsed through experimental verification, as well as the practical use and the model capability to contribute in the improvement of current standard CMM measuring capabilities.

11.
Sensors (Basel) ; 16(10)2016 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-27690052

RESUMEN

The development of an error compensation model for coordinate measuring machines (CMMs) and its integration into feature measurement is presented. CMMs are widespread and dependable instruments in industry and laboratories for dimensional measurement. From the tip probe sensor to the machine display, there is a complex transformation of probed point coordinates through the geometrical feature model that makes the assessment of accuracy and uncertainty measurement results difficult. Therefore, error compensation is not standardized, conversely to other simpler instruments. Detailed coordinate error compensation models are generally based on CMM as a rigid-body and it requires a detailed mapping of the CMM's behavior. In this paper a new model type of error compensation is proposed. It evaluates the error from the vectorial composition of length error by axis and its integration into the geometrical measurement model. The non-explained variability by the model is incorporated into the uncertainty budget. Model parameters are analyzed and linked to the geometrical errors and uncertainty of CMM response. Next, the outstanding measurement models of flatness, angle, and roundness are developed. The proposed models are useful for measurement improvement with easy integration into CMM signal processing, in particular in industrial environments where built-in solutions are sought. A battery of implementation tests are presented in Part II, where the experimental endorsement of the model is included.

12.
Percept Mot Skills ; 118(1): 126-44, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24724518

RESUMEN

Use of different effectors in two consecutive actions could generate an attentional shift between the effectors with shorter latencies in the second action of reaching. 18 participants (10 men; M age = 21.3 yr.) participated in an experiment with two main variables: (1) effector switching with two levels (Switching and No Switching), where the participants use or do not use a different motor effector for each action; (2) lifting muscles, i.e., the muscles involved in the first phase of the reaching, with two levels (finger-lifting muscle and palm-lifting muscle). Premotor time, Motor time, Reaction time, Movement time, and Total time were measured. For Premotor, Movement, and Total times, faster responses were observed when there was no switching of the effector. This delay could be due to an attentional shift between motor effectors and its relations with motor processes. Possible applications include the ergonomic design of device controls, considering that the use of the same effector is beneficial when fast reaction times are sought.


Asunto(s)
Movimiento/fisiología , Músculo Esquelético/fisiología , Memoria Implícita/fisiología , Extremidad Superior/fisiología , Atención , Electromiografía , Femenino , Humanos , Masculino , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Adulto Joven
13.
Schizophr Res ; 133(1-3): 199-204, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21907548

RESUMEN

Schizophrenia patients, particularly those with current delusions, show a cognitive bias known as jumping to conclusions, defined as a decision made quickly on the basis of little evidence. The aim of this work was to examine the underlying mechanisms of this cognitive bias by means of the Picture To Decision Task, which allows one to analyse the effect of the context on decisions made. We compared the performance of this task by 42 psychotic patients, 21 siblings of these patients and 77 controls. The results of the current study suggest that, relative to siblings and controls, patients display a general tendency to jump to conclusions, characterised by overestimating the conviction in their choices at the beginning of the decision process and by a lowered threshold for making decisions in ambiguous contexts, where a greater amount of information is required. These results are interpreted in terms of faulty appraisal, which would be the first mechanism responsible for the Jumping To Conclusions bias. Theoretical and clinical implications are discussed.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Toma de Decisiones , Trastornos Psicóticos/complicaciones , Trastornos Psicóticos/psicología , Adulto , Atención/fisiología , Sesgo , Emociones , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Estimulación Luminosa , Reconocimiento en Psicología/fisiología , Hermanos/psicología , Estadística como Asunto , Adulto Joven
14.
Anim Reprod Sci ; 118(1): 54-61, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19586729

RESUMEN

The aim of this study was to evaluate the cryoprotective effect of different freezing extenders against cryopreservation injuries on Iberian boar sperm. The sperm-rich fraction was collected and pooled from six sexually mature Iberian boars, and was frozen in different extenders containing glucose, lactose or fructose as sugar source and including Orvus ES Paste only in the freezing extender-2 (Glucose; Lactose and Fructose) or in both freezing extenders (Glucose2; Lactose2 and Fructose2). During the cryopreservation process, the supernatant was removed after the centrifugation step, then was extended with freezing extender-1 for the equilibration period and with freezing extender-2 immediately before freezing. Post-thaw sperm characteristics, such as plasma membrane integrity (SYBR-14/PI), mitochondrial function (Rhodamine 123) and acrosome integrity (NAR), were monitored. Overall sperm motility and the individual kinematic parameters of motile spermatozoa (assessed by the computer-aided sperm analysis system Sperm Class Analyzer [SCA]) were recorded in the different experimental treatments. Measurements were taken at 30 and 150 min post-thaw. The state of the acrosome after thawing did not show significant differences between the freezing extenders studied. Freezing-thawing caused a significant decrease (P<0.001) in plasma membrane integrity and in mitochondrial activity in the spermatozoa frozen with Orvus ES Paste in both freezing extenders. Furthermore, spermatozoa frozen with Orvus ES Paste in both freezing extenders exhibited lower (P<0.05) motility and kinematic parameters than those frozen in the absence of Orvus ES Paste in the first freezing extender. The spermatozoa frozen with the Lactose extender and with Orvus ES Paste only in the second freezing extender showed a better evolution of the motility and kinematic characteristics (P<0.05) over time. The deterioration in post-thaw sperm motility and kinematic parameters were concurrent with reduced sperm characteristics. It can be suggested that in the Iberian pig, the beneficial effects of Orvus ES Paste during the freezing process of spermatozoa is time dependent. The analysis of different sperm characteristics such as motility, plasma membrane integrity and mitochondrial function, determined that the extenders studied in the present experiment affected the quality of frozen-thawed semen in Iberian boar.


Asunto(s)
Criopreservación/métodos , Crioprotectores/farmacología , Preservación de Semen/métodos , Espermatozoides/efectos de los fármacos , Porcinos , Acrosoma/efectos de los fármacos , Acrosoma/fisiología , Animales , Criopreservación/veterinaria , Congelación , Calor , Masculino , Mitocondrias/efectos de los fármacos , Mitocondrias/fisiología , Análisis de Semen/veterinaria , Preservación de Semen/veterinaria , Espermatozoides/citología , Espermatozoides/fisiología , Espermatozoides/ultraestructura , Porcinos/fisiología
15.
Biotechnol Adv ; 27(2): 153-76, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19041387

RESUMEN

In aerobic bioprocesses, oxygen is a key substrate; due to its low solubility in broths (aqueous solutions), a continuous supply is needed. The oxygen transfer rate (OTR) must be known, and if possible predicted to achieve an optimum design operation and scale-up of bioreactors. Many studies have been conducted to enhance the efficiency of oxygen transfer. The dissolved oxygen concentration in a suspension of aerobic microorganisms depends on the rate of oxygen transfer from the gas phase to the liquid, on the rate at which oxygen is transported into the cells (where it is consumed), and on the oxygen uptake rate (OUR) by the microorganism for growth, maintenance and production. The gas-liquid mass transfer in a bioprocess is strongly influenced by the hydrodynamic conditions in the bioreactors. These conditions are known to be a function of energy dissipation that depends on the operational conditions, the physicochemical properties of the culture, the geometrical parameters of the bioreactor and also on the presence of oxygen consuming cells. Stirred tank and bubble column (of various types) bioreactors are widely used in a large variety of bioprocesses (such as aerobic fermentation and biological wastewater treatments, among others). Stirred tanks bioreactors provide high values of mass and heat transfer rates and excellent mixing. In these systems, a high number of variables affect the mass transfer and mixing, but the most important among them are stirrer speed, type and number of stirrers and gas flow rate used. In bubble columns and airlifts, the low-shear environment compared to the stirred tanks has enabled successful cultivation of shear sensitive and filamentous cells. Oxygen transfer is often the rate-limiting step in the aerobic bioprocess due to the low solubility of oxygen in the medium. The correct measurement and/or prediction of the volumetric mass transfer coefficient, (k(L)a), is a crucial step in the design, operation and scale-up of bioreactors. The present work is aimed at the reviewing of the oxygen transfer rate (OTR) in bioprocesses to provide a better knowledge about the selection, design, scale-up and development of bioreactors. First, the most used measuring methods are revised; then the main empirical equations, including those using dimensionless numbers, are considered. The possible increasing on OTR due to the oxygen consumption by the cells is taken into account through the use of the biological enhancement factor. Theoretical predictions of both the volumetric mass transfer coefficient and the enhancement factor that have been recently proposed are described; finally, different criteria for bioreactor scale-up are considered in the light of the influence of OTR and OUR affecting the dissolved oxygen concentration in real bioprocess.


Asunto(s)
Bacterias/metabolismo , Reactores Biológicos , Modelos Biológicos , Oxígeno/metabolismo , Algoritmos , Bacterias/crecimiento & desarrollo , Microbiología Industrial , Cinética
16.
J Assist Reprod Genet ; 25(9-10): 445-52, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18839305

RESUMEN

PURPOSE: The objective of this study was to evaluate the effect of men and recipient age on the reproductive outcome of our oocyte donation program. METHODS: We retrospectively analyzed 915 cycles, taking into account men and recipient age, separately and together. RESULTS: The significant cut off value for men and recipients age with incidence in the reproductive outcome was 39 years. Recipient older than 38 years presented a significantly lower pregnancy and implantation rates than others (44.92 vs. 55.75 +/- 1.53%, 25.66 vs. 32.79 +/- 1.64%). If men age was older than 38, a significant reduction in pregnancy and implantation rates was observed, too (46.0 vs. 54.65%, 26.00 +/- 1.52 vs. 32.43 +/- 1.65%). When men and recipient age was analyzed together, a reduction in pregnancy and implantation was detected only if both were older than 38. CONCLUSIONS: Present study suggests that age has a detrimental effect on the reproductive outcome of oocyte donation cycles when both men and recipient are > or = 39 years old.


Asunto(s)
Envejecimiento , Donación de Oocito , Resultado del Embarazo , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Índice de Embarazo , Estudios Retrospectivos , Adulto Joven
17.
J Environ Manage ; 88(4): 1552-61, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17825476

RESUMEN

This study investigates the effect of environmental investment and related spillover effects on productivity in the agricultural sector by using a panel data of horticultural firms in Andalusia (Southern Spain). The results indicate a positive relationship between firm investment in environmental practices and productivity improvement, also showing the presence of positive environmental spillovers. In a second-stage of analysis, the incidence of environmental factors in firm specific individual technical efficiency is estimated. This analysis also shows the link between environmental knowledge diffusion and horticultural firms' performance.


Asunto(s)
Agricultura , Conservación de los Recursos Naturales , Eficiencia , Modelos Teóricos , España
18.
J Androl ; 28(2): 273-81, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17021334

RESUMEN

The use of mammalian oocytes to assess human sperm functionality could be a helpful tool with potential applications in clinical and research programs. In an attempt to develop the pig model, the aim of the present work was to study the interaction between human spermatozoa and pig oocytes at the zona pellucida (ZP), the oolemma, and the ooplasm levels. In vitro matured pig oocytes and human spermatozoa from fertile and low-fertility donors were employed. The induction of the acrosome reaction by the ZP, the ability of the sperm to penetrate the oocyte after coincubation, and the male pronuclear formation after ICSI were evaluated. Human spermatozoa can bind to pig ZP and undergo the acrosome reaction (15% to 58%, depending on the individual); they are not able to fuse with the oolemma but they can decondense and form a male pronucleus (40%-100%) when injected into pig oocytes. In conclusion, this study shows that pig oocytes can be a useful model to assess human sperm functionality.


Asunto(s)
Oocitos/fisiología , Interacciones Espermatozoide-Óvulo/fisiología , Espermatozoides/fisiología , Reacción Acrosómica/fisiología , Animales , Femenino , Humanos , Masculino , Modelos Animales , Inyecciones de Esperma Intracitoplasmáticas , Porcinos , Zona Pelúcida/fisiología
19.
Biotechnol Bioeng ; 92(6): 761-72, 2005 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-16155951

RESUMEN

Oxygen mass transfer in sparged stirred tank bioreactors has been studied. The rate of oxygen mass transfer into a culture in a bioreactor is affected by operational conditions and geometrical parameters as well as the physicochemical properties of the medium (nutrients, substances excreted by the micro-organism, and surface active agents that are often added to the medium) and the presence of the micro-organism. Thus, oxygen mass transfer coefficient values in fermentation broths often differ substantially from values estimated for simple aqueous solutions. The influence of liquid phase physicochemical properties on kLa must be divided into the influence on k(L) and a, because they are affected in different ways. The presence of micro-organisms (cells, bacteria, or yeasts) can affect the mass transfer rate, and thus kLa values, due to the consumption of oxygen for both cell growth and metabolite production. In this work, theoretical equations for kLa prediction, developed for sparged and stirred tanks, taking into account the possible oxygen mass transfer enhancement due to the consumption by biochemical reactions, are proposed. The estimation of kLa is carried out taking into account a strong increase of viscosity broth, changes in surface tension and different oxygen uptake rates (OURs), and the biological enhancement factor, E, is also estimated. These different operational conditions and changes in several variables are performed using different systems and cultures (xanthan aqueous solutions, xanthan production cultures by Xanthomonas campestris, sophorolipids production by Candida bombicola, etc.). Experimental and theoretical results are presented and compared, with very good results.


Asunto(s)
Reactores Biológicos/microbiología , Candida/metabolismo , Oxígeno/metabolismo , Xanthomonas campestris/metabolismo , Adsorción , Difusión , Modelos Biológicos , Modelos Químicos , Consumo de Oxígeno/fisiología , Polisacáridos Bacterianos/biosíntesis , Soluciones
20.
Cir. Esp. (Ed. impr.) ; 77(4): 236-239, abr. 2005. ilus, tab
Artículo en Es | IBECS | ID: ibc-037761

RESUMEN

El carcinoma insular de tiroides es una entidad infrecuente, denominada así por Carcangiu et al, en 1984, cuando describió su característica anatomía patológica. Desde un punto de vista morfológico, y también clínico, se le considera en una posición intermedia entre el carcinoma diferenciado de tiroides, papilar o folicular, y el indiferenciado o anaplásico. No obstante, la mayoría de los autores lo consideran una entidad independiente y aparte. Su pronóstico es peor que el del carcinoma tiroideo clásico, y la mayoría de los autores recomienda un tratamiento enérgico, que en algunos casos puede proporcionar supervivencias prolongadas. Presentamos a 2 pacientes que, tras el tratamiento de un tumor primario, sufrieron recidiva, que fue tratada, pero con una evolución diferente (AU)


Insular carcinoma of the thyroid is an infrequent entity, named in 1984 by Carcangiu when he described its characteristic histology. Clinically and morphologically it is considered to be in an intermediate position between well-differen-tiated carcinoma of the thyroid (papillary or follicular) and undifferentiated or anaplastic carcinoma of the thyroid. However, most authors believe it to be an independent entity. The prognosis of this tumor is worse than that of classic carcinoma of the thyroid, and most authors advise aggressive therapy, which in some cases can achieved prolonged survival. We describe 2 patients who experienced recurrence after treatment for the primary tumor. The recurrences were treated but the clinical courses differed (AU)


Asunto(s)
Femenino , Adulto , Persona de Mediana Edad , Humanos , Carcinoma/complicaciones , Carcinoma/cirugía , Toracotomía/métodos , Toracotomía , Tomografía Computarizada de Emisión/métodos , Escisión del Ganglio Linfático/métodos , Neoplasias de la Tiroides/diagnóstico , Neoplasias de la Tiroides/cirugía , Tiroidectomía/métodos , Neoplasias de la Tiroides/radioterapia , Neoplasias de la Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/epidemiología
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