646 research outputs found
Producción de emulsiones submicrónicas formuladas con dos biodisolventes y tres tensioactivos ecológicos diferentes
El objetivo de este trabajo fue comparar las propiedades emulsionantes de tres tensioactivos ecológicos que derivan del aceite de coco para la preparación de emulsiones aceite-en-agua formuladas con una mezcla de disolventes verdes como fase dispersa, N,Ndimetildecanamiday a-pineno. La reología, la difracción láser, la microscopía óptica y el “multiple lightscattering” fueron las técnicas principales utilizadas para evaluar las propiedades emulsionantes de estos tensioactivos. Se obtuvieron emulsiones ligeramente concentradas usando cualquiera de los tensio activos estudiados, que difieren en el número de grupos etoxilados.Sin embargo, se ha demostrado que el uso del tensioactivo no-iónico con el mayor número de grupos etoxilados (Levenol C201) es adecuado por tresmotivos: (a) permite obtener los menores tamaños degota, (b) proporciona suficiente viscosidad para prevenirel cremado y (c) no se produce desestabilización por coalescencia. La caracterización sistemática quese presenta en este trabajo proporciona importantes resultados sobre las propiedades emulsionantes de los ésteres polietoxilados de glicerina derivados del aceitede coco, que pueden ser utilizados para el desarrollo de nuevos productos biocompatibles
Corrective shoeing as the only treatment of a congenital flexural deformity of the distal interphalangeal joint in the hind limb of a Spanish filly
En el presente artículo se describe el caso de una potra PRE, de 18
meses de edad, con una deformación flexural congénita de la articulación
interfalangiana distal del miembro pelviano derecho, que respondió a una serie
de herrados correctivos. Existen diversas opciones terapéuticas en una
deformación flexural en la articulación interfalangiana distal en potros:
tratamiento conservador (modificación de la dieta, ejercicio controlado,
oxitetraciclina y control del dolor), quirúrgico (desmotomía del ligamento
accesorio del tendón del flexor digital profundo y tenotomía del flexor digital
profundo) y herrado terapéutico. En este caso, debido a la larga duración del
proceso y a la negativa del propietario a someter a la potra a cirugía, se optó
por un tratamiento ortopédico podológico. En el primer herrado, se aplicó una
herradura de tamaño superior al casco, con extensión craneal, sin recortar los
talones. Además, se hicieron claveras alternativas en las cuartas partes y
talones. En el segundo herrado, 45 días después, se colocó una herradura sin
compensar en las lumbres, del mismo tamaño que la utilizada en el primer
herrado. Debido al crecimiento del casco, se recortaron los talones. En el tercer
herrado, 45 días tras el segundo, las lumbres habían crecido, ocupando la
extensión craneal de la herradura. Se mantuvieron las claveras alternativas
para evitar clavar en hombros, favoreciendo así la expansión del casco en esta
zona. Además, para mejorar la sujeción al caso se usó una herradura con
pestañas en los hombros. Tras la serie de tres herrados, se apreció una
notable mejoría clínica en esta potra. En conclusión, la deformación flexural
congénita de la articulación interfalangiana distal puede responder a una serie
de herrados correctores en algunos casos, sin necesidad de tratamientos
adicionales.In the present article, we describe a congenital flexural limb deformity
affecting the distal interphalangeal joint of the right hind limb in an 18-months
old Spanish filly which positively responded to serial corrective shoeing
procedures. There are different therapeutic options for the treatment of
flexural limb deformity in the distal interphalangeal joint in horses:
conservative treatment (changes in diet, controlled exercise intensity,
oxytetracycline and medical pain management), surgical (inferior check
ligament desmotomy and deep digital flexor tenotomy) and therapeutic
shoeing. In the case presented here, because of the long duration of the
process and because the owner refused the surgical option, we selected the
orthopedic shoeing. In the first shoeing, we used a shoe bigger than the hoof,
with cranial toe extensions. Additionally, we use alternative nail holes in
quarters and heels. In the second shoeing, carried out 45 days after the first
shoeing, we used a non-compensated shoe of the same size those used in the
first shoeing. Furthermore, and because of the growth of the hoof, the heels
were lowered. In the third shoeing, performed 45 days after the second, we
observed that the toe grew up in the cranial toe extensions. We kept the
alternative nail holes in order to avoid the holes in the toes promoting the
growth of the hoof in the toes. Moreover, and in order to hold better the shoe,
we applied with clicks in the toes. After 3 shoeing procedures, the filly
underwent a marked improvement. It is concluded that a congenital flexural
deformity affecting the distal interphalangeal joint might favorably respond in
some cases to a series of corrective shoeing procedures without the necessity
of additional treatments
How can we all help conserve nature?
When we speak about conserving nature, we are really talking about taking care of our future, because nature provides essential resources for our survival and enjoyment. We asked an international group of scientists working on different environmental issues worldwide to identify important practical actions that we can all do to help conserve nature. We obtained nearly 100 responses and grouped them into three main categories: (1) Actions to reduce our ecological footprint; (2) Actions to conserve nature; and (3) Actions that help us connect with nature. We briefly explain actions that can be performed daily to reduce our impact on nature, and provide some useful links for further readin
Memory for Object Location in Augmented Reality: The Role of Gender and the Relationship Among Spatial and Anxiety Outcomes
The potential of augmented reality (AR) technology for the study of spatial memory and orientation is a new research field. AR defines systems that attempt to enhance the user's experience with the physical world. In our app, we enhance the sense of sight by adding interactive 3D elements to the real environment. Our app can be used in any real environment so that the experimental conditions during the tasks and the way in which an individual navigates are similar to those used in real life. With AR, the experimenter has a high level of control of the task and can store the participant's responses accurately. The classical factors that influence an individual's performance on virtual spatial tasks are gender and cognitive factors. The influence of emotional factors on spatial performance has been studied more recently. Since AR tasks for the study of spatial memory and spatial orientation are new developments, little is known about the factors that are related to performance on tasks of this type. In our study, we tested 46 young adults (26 women) in an AR object-location task that was performed in a building. The participants had to memorize the position of eight virtual objects while they were walking through the environment. We also assessed the participants' performance on an object-recall task, a map-pointing task, and a paper-and-pencil spatial orientation task. The self-reported importance of different spatial strategies for wayfinding and the levels of trait anxiety and wayfinding anxiety were also evaluated. Our findings indicate that men performed better on the spatial paper-and-pencil test and spent more time completing the learning phase of the AR task. The spatial memory for the location of the objects in AR and on the map correlated positively. Anxiety was related to individual differences in the self-reported use of a spatial orientation strategy, but the association among them was weak. Trait anxiety was positively related to the time employed by the participants during the learning phase of the AR task, whereas wayfinding anxiety correlated negatively with the preference for an orientation strategy. Our results highlight the importance of anxiety in spatial orientation
Magnetic order and magnetic properties of the oxygen deficient SmBaMn2O5 layered perovskite
Magnetism in SmBaMn2O5 was investigated on a single crystal by magnetic and neutron diffraction measurements. This is an oxygen deficient perovskite with a layered ordering of Sm and Ba cations. Mn atoms are coordinated with five oxygens forming a square pyramid and they are ordered in a checkerboard pattern of expanded-compressed pyramids in the ab-plane. The neutron diffraction study revealed a ferrimagnetic ordering of Mn moments below TN=134 K. Macroscopic measurements reveal a very anisotropic behavior. Measurements with the external magnetic field parallel (M||c) and perpendicular (M¿c) to the c-axis confirm that this is the easy axis above 10 K. Below this temperature, the Sm sublattice begins to polarize and the magnetization M||c decreases while M¿c experiences a huge increase. This indicates that Sm moments begin to order around 10 K in the ab-plane with a minor component on the c-axis that opposes the overall magnetization from Mn sublattices
Association between parameters related to oxidative stress and trace minerals in Athletes
The aim of the present study was to evaluate the basal concentrations of malondialdehyde (MDA) nonenzymatic antioxidants, such as ascorbic acid, a-tocopherol, and retinol in plasma or erythrocytes, and the plasma concentrations of 16 trace minerals in endurance athletes from Extremadura (Spain). In addition, we aimed to assess the possible relationships between some parameters related to cellular oxidative stress with plasma concentrations of some trace minerals. Sixty-two national long-distance men athletes participated in this study. The parameters related to oxidative stress and antioxidant activity were analyzed through high pressure liquid chromatography (HPLC), and trace minerals analysis was performed by inductively coupled plasma mass spectrometry (ICP-MS). We found that plasma MDA was positively correlated with selenium and rubidium. Plasma ascorbic acid was positively correlated with manganese and negatively correlated with cobalt and cadmium. Erythrocyte ascorbic acid was related to arsenic and cesium. Plasma a-tocopherol correlated with copper and manganese negatively and positively with arsenic. Erythrocyte a-tocopherol was positively related to copper, rubidium, and lithium. The findings show that athletes with a high degree of training should monitor their intake and concentrations of a-tocopherol for its fundamental role of neutralizing the excess of reactive oxygen species produced by exercise and the prooxidant effects of several minerals such as arsenic, copper, and lithium
Electromodulation of the Magnetoresistance in Diluted Magnetic Semiconductors Based Heterostructures
We study the properties of heterostructures formed by two layers of diluted
magnetic semiconductor separated by a nonmagnetic semiconductor layer. We find
that there is a RKKY-type exchange coupling between the magnetic layers that
oscilles between ferromagnetic and antiferromagnetic as a function of the
different parameters in the problem. The different transport properties of
these phases make that this heterostructure presents strong magnetoresistive
effects. The coupling can be also modified by an electric field. We propose
that it is possible to alter dramatically the electrical resistance of the
heterostructure by applying an electric field. Our results indicate that in a
single gated sample the magnetoresistance could be modulated by with an
electrical bias voltage.Comment: 4 pages, 5 figures include
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